Pierre Busson | Gustave Roussy - Paris Sud University (original) (raw)

Papers by Pierre Busson

Cancer Immunology Research, 2016

Galectin-9 (gal-9) is a multifunctional β-galactoside-binding lectin which is frequently released... more Galectin-9 (gal-9) is a multifunctional β-galactoside-binding lectin which is frequently released in the extra-cellular medium where it can modulate various biological activities (cell adhesion, migration), but it acts mainly as a negative regulator of the immune response. Our team has shown an intense and inappropriate production of gal-9 by malignant epithelial cells in Epstein-Barr virus-associated nasopharyngeal carcinoma. Other groups and ourselves have shown that gal-9 is very abundant in plasma samples from patients chronically infected by hepatitis C or B virus, and particularly in those with hepatocellular carcinomas. The most prominent immunosuppressive effects reported for gal-9 are the induction of apoptosis of CD4+ T-helper 1 (Th1) cells, exhaustion of CD8+ T cells, and stimulation of regulatory T cell activity. However, a recent study (and our own data) demonstrates that gal-9 can also activate and expand a subset of IFNγ; producing Th1 cells and central memory T cells...

Epstein-Barr Virus and Human Disease, 1987

IL-1 is the term currently accepted for a cytokine which has a variety of important pleomorphic f... more IL-1 is the term currently accepted for a cytokine which has a variety of important pleomorphic functions in immuno-regulation and inflammation (1). It plays a central role in T cell activation, mainly through induction of IL-2 secretion by activated T cells.

Cancer Research, 2012

Nasopharyngeal carcinomas (NPC) are malignant epithelial tumors of the nasopharyngeal cavity. The... more Nasopharyngeal carcinomas (NPC) are malignant epithelial tumors of the nasopharyngeal cavity. They are consistently associated with the Epstein-Barr virus (EBV). Though NPCs are on average more radiosensitive and chemosensitive than other tumors of the upper aero-digestive tract, many therapeutic challenges remain. In this context the development of therapeutic approaches taking better account of biological characteristics of NPC and well defined biological targets remains a priority. We have previously reported a cooperative effect of the TLR3-agonist poly(I:C) combined to a Smac-mimetic against NPC cells. (Friboulet et al., Neoplasia 2008, 10: 1183-1194 and BMC cancer 2010, 10: 327). However Poly(I:C) is a ligand not only for the TLR3 but also other receptors of double-stranded RNAs, like RIG1 and PKR. In contrast Poly(A:U) is much more specific for TLR3. In addition, Poly(A:U) has less secondary effects in patients and has already been successfully used in a phase III clinical tr...

Cancer Research, 2013

Epstein-Barr virus (EBV) related nasopharyngeal carcinoma (NPC) is the third leading cause of vir... more Epstein-Barr virus (EBV) related nasopharyngeal carcinoma (NPC) is the third leading cause of virus-related human malignancy. On average, NPCs are more radiosensitive and chemosensitive than other head and neck tumors. However, local relapse and distant organ metastases still raise serious therapeutic problems. The aim of this study was to investigate the potential of the novel pan-HDAC inhibitor Abexinostat (S78454) for the treatment of NPC. Three types of EBV-positive NPC cells have been used as targets for in vitro and in vivo treatments. C666-1 and C17 cells were first xenotransplanted from the patients to nude mice and, in a second stage, adapted to permanent in vitro culture. In contrast, C15 cells are still propagated exclusively as xenografts; however, they can be used in short term culture assays. S78454 was applied to these cells either alone or in combination with cis-platinum. All three types of NPC cells - C666-1, C15 and C17 - were sensitive to the cytotoxic effects of...

Proceedings of the National Academy of Sciences, 1987

Applied and Environmental Microbiology, 2001

Clostridium botulinum neurotoxin type A (BTx-A) is known to inhibit the release of acetylcholine ... more Clostridium botulinum neurotoxin type A (BTx-A) is known to inhibit the release of acetylcholine at the neuromuscular junctions and synapses and to cause neuroparalysis and death. In this study, we have identified two monoclonal antibodies, BT57-1 and BT150-3, which protect ICR mice against lethal doses of BTx-A challenge. The neutralizing activities for BT57-1 and BT150-3 were 10 3 and 10 4 times the 50% lethal dose, respectively. Using immunoblotting analysis, BT57-1 was recognized as a light chain and BT150-3 was recognized as a heavy chain of BTx-A. Also, applying the phage display method, we investigated the antibodies' neutralizing B-cell epitopes. These immunopositive phage clones displayed consensus motifs, Asp-Pro-Leu for BT57-1 and Cys-X-Asp-Cys for BT150. The synthetic peptide P4M (KGTFDPLQEPRT) corresponded to the phage-displayed peptide selected by BT57-1 and was able to bind the antibodies specifically. This peptide was also shown by competitive inhibition assay to...

International audienceMechanisms of tumor immune escape are quite diverse and require specific ap... more International audienceMechanisms of tumor immune escape are quite diverse and require specific approaches for their exploration in syngeneic tumor models. In several human malignancies, galectin-9 (gal-9) is suspected to contribute to the immune escape. However, in contrast with what has been done for the infiltrating cells, the contribution of gal-9 produced by malignant cells has never been demonstrated in an animal model. Therefore, we derived isogenic clones—either positive or negative for gal-9—from the MB49 murine bladder carcinoma cell line. A progressive and consistent reduction of tumor growth was observed when gal-9-KO cells were subjected to serial transplantations into syngeneic mice. In contrast, tumor growth was unaffected during parallel serial transplantations into nude mice, thus linking tumor inhibition to the enhancement of the immune response against gal-9-KO tumors. This stronger immune response was at least in part explained by changing patterns of response to ...

<b>Copyright information:</b>Taken from "Biological characterization of two xeno... more <b>Copyright information:</b>Taken from "Biological characterization of two xenografts derived from human CUPs (carcinomas of unknown primary)"http://www.biomedcentral.com/1471-2407/7/225BMC Cancer 2007;7():225-225.Published online 18 Dec 2007PMCID:PMC2241840. : microvillosities; : large vacuole suggestive of aberrant autophagy.

<b>Copyright information:</b>Taken from "Biological characterization of two xeno... more <b>Copyright information:</b>Taken from "Biological characterization of two xenografts derived from human CUPs (carcinomas of unknown primary)"http://www.biomedcentral.com/1471-2407/7/225BMC Cancer 2007;7():225-225.Published online 18 Dec 2007PMCID:PMC2241840. Panel A : surgical specimen (× 200). Panel B: xenografted tumor (× 100). Note that specific staining is mainly associated with the plasma membrane of malignant cells.

Chemical Science, 2018

FRET and rolling circle amplification outperform RT-qPCR for microRNA diagnostics in clinical sam... more FRET and rolling circle amplification outperform RT-qPCR for microRNA diagnostics in clinical samples.

Anticancer research

Aberrant methylation of tumor suppressor gene (TSG) promoters has been extensively investigated i... more Aberrant methylation of tumor suppressor gene (TSG) promoters has been extensively investigated in nasopharyngeal carcinomas (NPC) from South East Asia but not from North Africa. The methylation status of p16, deleted in lung and esophageal cancer (DLEC1), zinc finger, MYND-type containing 10 (BLU) and E-cadherin gene promoters was investigated in 44 Tunisian NPC biopsies and three NPC xenografts, by methylation-specific PCR (MSP) combined with a quantitative assessment of some of the samples. The frequencies of aberrant promoter methylation were similar to previous figures reported for Asian series: p16 27/44 (65%), DLEC1 38/44 (86.3%), BLU 15/44 (34.1%) and E-cadherin 35/44 (79.5%). Although in other malignancies, aberrant promoter hypermethylation increases with patient age, it was at the same high frequency in the juvenile and adult forms of Tunisian NPCs. However, there was a strong association between aberrant methylation of E-cadherin promoter and lymph node invasion (p < ...

Nature Communications, 2021

Nasopharyngeal cancer (NPC), endemic in Southeast Asia, lacks effective diagnostic and therapeuti... more Nasopharyngeal cancer (NPC), endemic in Southeast Asia, lacks effective diagnostic and therapeutic strategies. Even in high-income countries the 5-year survival rate for stage IV NPC is less than 40%. Here we report high somatostatin receptor 2 (SSTR2) expression in multiple clinical cohorts comprising 402 primary, locally recurrent and metastatic NPCs. We show that SSTR2 expression is induced by the Epstein–Barr virus (EBV) latent membrane protein 1 (LMP1) via the NF-κB pathway. Using cell-based and preclinical rodent models, we demonstrate the therapeutic potential of SSTR2 targeting using a cytotoxic drug conjugate, PEN-221, which is found to be superior to FDA-approved SSTR2-binding cytostatic agents. Furthermore, we reveal significant correlation of SSTR expression with increased rates of survival and report in vivo uptake of the SSTR2-binding 68Ga-DOTA-peptide radioconjugate in PET-CT scanning in a clinical trial of NPC patients (NCT03670342). These findings reveal a key role ...

Consistent high concentration of the viral microRNA

Journal of Virology

A family of mRNAs that are transcribed rightward through the BamHI A fragment have been detected ... more A family of mRNAs that are transcribed rightward through the BamHI A fragment have been detected in C15, a nasopharyngeal carcinoma (NPC) which has been passaged in nude mice. Northern (RNA) blot hybridizations indicate that these RNAs are also expressed in three other NPCs which have been established in nude mice and in an NPC obtained at biopsy. Moreover, hybridization in situ detected transcription from BamHI A in 12 NPCs and 1 Epstein-Barr virus (EBV)-containing carcinoma of the parotid gland. In each case, transcription was detected in all of the malignant epithelial cells. Transcription was not detected in two cases of EBV-positive lymphoma biopsies by in situ hybridization nor in latently infected EBV-positive lymphoblastoid cell lines by Northern blot hybridization. The consistent transcription of these sequences in latently infected epithelial malignancy but not in lymphoid cells suggests that this viral function is associated with latent EBV infection of epithelial cells. ...

ACS Sensors

The quantification of very low concentrations of circulating tumor DNA (ctDNA) biomarkers from li... more The quantification of very low concentrations of circulating tumor DNA (ctDNA) biomarkers from liquid biopsies has become an important requirement for clinical diagnostics and personalized medicine. In particular, the simultaneous detection of wild-type dsDNA and their cancer-related counterparts presenting single point mutations with simple, sensitive, specific, and reproducible technologies is paramount for ctDNA assays in clinical practice. Here, we present the development and evaluation of an amplified dsDNA assay based on a combination of isothermal rolling circle amplification (RCA) and time-gated Förster resonance energy transfer (TG-FRET) between a Tb donor and two dye (Cy3.5 and Cy5.5) acceptors. The RCA-FRET assay is free of washing and separation steps and can quantify both wild type and mutated (V600E) dsDNA in the BRAF gene from a single sample in the 75 fM to 4.5 pM (4.5x105 to 2.7x107 copies) concentration range. The assay includes all steps from denaturation of the dsDNA targets to the final duplexed quantification of wild-type and mutated targets. High assay performance at different dsDNA sequence lengths and high target specificity even in the presence of a large excess of non-specific cell-free DNA from human plasma samples demonstrated the applicability to clinical samples. The RCA-FRET single-point-mutation sensor has the potential to become an important complementary technique for analyzing liquid biopsies in advanced cancer diagnostics.

Cellular Oncology

Purpose: Head and neck squamous cell carcinoma (HNSCC) is one of the most common cancers. Concurr... more Purpose: Head and neck squamous cell carcinoma (HNSCC) is one of the most common cancers. Concurrent radio-chemotherapy is the standard of care for advanced tumors. However, there is still a need for more efficient treatments with less secondary effects, resulting from high doses. Therefore, we undertook to explore the therapeutic potential of ternary combinations-bringing together irradiation, cis-platinum and a TLR3 agonist, poly(I:C) with aim to reduce dosage of each treatment. This approach is based on our previous studies showing a selective cytotoxic effect of TLR3 agonists against malignant cells when it is combined with other anti-neoplastic agents. Methods: We have explored the cell survival of the head and neck cancer cells (Detroit 562, FaDu, SQ20B and Cal27) by MTT and caspase 3/7 assay. The radiosensitization effect of poly(I:C) and cisplatin treatment was shown by western blot, cell cycle analysis, ROS determination and qPCR. Results: We have shown here that the combination of poly(I:C) and cisplatin can downregulate cIAP2 and survivin expression, reduce cell survival, induce anti-apoptotic gene expression and apoptosis, generate ROS formation and cause G2/M phase arrest in HNSCC cell lines. Conclusions: Our results show that poly(I:C) and cisplatin combination therapy reduces cancer cell survival and induces radiosensitivity in HNSCC cell lines thus providing a rationale for the development of a novel strategy in head and neck cancer treatment.

Laboratory investigation; a journal of technical methods and pathology, Jan 16, 2018

Epstein-Barr virus (EBV) infects more than 90% of the adult human population. Undifferentiated na... more Epstein-Barr virus (EBV) infects more than 90% of the adult human population. Undifferentiated nasopharyngeal carcinoma (NPC) is common in Southeast Asia, with a particularly high incidence among southern Chinese. The EBV genome can be detected in practically all cancer cells in undifferentiated NPC. The role of EBV in pathogenesis of undifferentiated NPC remains elusive. NPC cell lines are known to be difficult to establish in culture. The EBV+ve NPC cell lines, even if established in culture, rapidly lost their EBV episomes upon prolonged propagation. At present, the C666-1 NPC cell line, which is defective in lytic EBV reactivation, is the only EBV+ve NPC cell line available for NPC and EBV research. The need to establish new and representative NPC cell lines is eminent for NPC and EBV research. In this study, we report the use of the Rho-associated kinase inhibitor (Y-27632) has facilitated the establishment of a new EBV+ve NPC cell line from an earlier established NPC xenograft...

Cancers, Jan 6, 2018

The presence of the Epstein-Barr virus (EBV)-encoded nuclear antigen-1 (EBNA1) protein in all EBV... more The presence of the Epstein-Barr virus (EBV)-encoded nuclear antigen-1 (EBNA1) protein in all EBV-carrying tumours constitutes a marker that distinguishes the virus-associated cancer cells from normal cells and thereby offers opportunities for targeted therapeutic intervention. EBNA1 is essential for viral genome maintenance and also for controlling viral gene expression and without EBNA1, the virus cannot persist. EBNA1 itself has been linked to cell transformation but the underlying mechanism of its oncogenic activity has been unclear. However, recent data are starting to shed light on its growth-promoting pathways, suggesting that targeting EBNA1 can have a direct growth suppressing effect. In order to carry out its tasks, EBNA1 interacts with cellular factors and these interactions are potential therapeutic targets, where the aim would be to cripple the virus and thereby rid the tumour cells of any oncogenic activity related to the virus. Another strategy to target EBNA1 is to i...

Cancer Immunology Research, 2016

Galectin-9 (gal-9) is a multifunctional β-galactoside-binding lectin which is frequently released... more Galectin-9 (gal-9) is a multifunctional β-galactoside-binding lectin which is frequently released in the extra-cellular medium where it can modulate various biological activities (cell adhesion, migration), but it acts mainly as a negative regulator of the immune response. Our team has shown an intense and inappropriate production of gal-9 by malignant epithelial cells in Epstein-Barr virus-associated nasopharyngeal carcinoma. Other groups and ourselves have shown that gal-9 is very abundant in plasma samples from patients chronically infected by hepatitis C or B virus, and particularly in those with hepatocellular carcinomas. The most prominent immunosuppressive effects reported for gal-9 are the induction of apoptosis of CD4+ T-helper 1 (Th1) cells, exhaustion of CD8+ T cells, and stimulation of regulatory T cell activity. However, a recent study (and our own data) demonstrates that gal-9 can also activate and expand a subset of IFNγ; producing Th1 cells and central memory T cells...

Epstein-Barr Virus and Human Disease, 1987

IL-1 is the term currently accepted for a cytokine which has a variety of important pleomorphic f... more IL-1 is the term currently accepted for a cytokine which has a variety of important pleomorphic functions in immuno-regulation and inflammation (1). It plays a central role in T cell activation, mainly through induction of IL-2 secretion by activated T cells.

Cancer Research, 2012

Nasopharyngeal carcinomas (NPC) are malignant epithelial tumors of the nasopharyngeal cavity. The... more Nasopharyngeal carcinomas (NPC) are malignant epithelial tumors of the nasopharyngeal cavity. They are consistently associated with the Epstein-Barr virus (EBV). Though NPCs are on average more radiosensitive and chemosensitive than other tumors of the upper aero-digestive tract, many therapeutic challenges remain. In this context the development of therapeutic approaches taking better account of biological characteristics of NPC and well defined biological targets remains a priority. We have previously reported a cooperative effect of the TLR3-agonist poly(I:C) combined to a Smac-mimetic against NPC cells. (Friboulet et al., Neoplasia 2008, 10: 1183-1194 and BMC cancer 2010, 10: 327). However Poly(I:C) is a ligand not only for the TLR3 but also other receptors of double-stranded RNAs, like RIG1 and PKR. In contrast Poly(A:U) is much more specific for TLR3. In addition, Poly(A:U) has less secondary effects in patients and has already been successfully used in a phase III clinical tr...

Cancer Research, 2013

Epstein-Barr virus (EBV) related nasopharyngeal carcinoma (NPC) is the third leading cause of vir... more Epstein-Barr virus (EBV) related nasopharyngeal carcinoma (NPC) is the third leading cause of virus-related human malignancy. On average, NPCs are more radiosensitive and chemosensitive than other head and neck tumors. However, local relapse and distant organ metastases still raise serious therapeutic problems. The aim of this study was to investigate the potential of the novel pan-HDAC inhibitor Abexinostat (S78454) for the treatment of NPC. Three types of EBV-positive NPC cells have been used as targets for in vitro and in vivo treatments. C666-1 and C17 cells were first xenotransplanted from the patients to nude mice and, in a second stage, adapted to permanent in vitro culture. In contrast, C15 cells are still propagated exclusively as xenografts; however, they can be used in short term culture assays. S78454 was applied to these cells either alone or in combination with cis-platinum. All three types of NPC cells - C666-1, C15 and C17 - were sensitive to the cytotoxic effects of...

Proceedings of the National Academy of Sciences, 1987

Applied and Environmental Microbiology, 2001

Clostridium botulinum neurotoxin type A (BTx-A) is known to inhibit the release of acetylcholine ... more Clostridium botulinum neurotoxin type A (BTx-A) is known to inhibit the release of acetylcholine at the neuromuscular junctions and synapses and to cause neuroparalysis and death. In this study, we have identified two monoclonal antibodies, BT57-1 and BT150-3, which protect ICR mice against lethal doses of BTx-A challenge. The neutralizing activities for BT57-1 and BT150-3 were 10 3 and 10 4 times the 50% lethal dose, respectively. Using immunoblotting analysis, BT57-1 was recognized as a light chain and BT150-3 was recognized as a heavy chain of BTx-A. Also, applying the phage display method, we investigated the antibodies' neutralizing B-cell epitopes. These immunopositive phage clones displayed consensus motifs, Asp-Pro-Leu for BT57-1 and Cys-X-Asp-Cys for BT150. The synthetic peptide P4M (KGTFDPLQEPRT) corresponded to the phage-displayed peptide selected by BT57-1 and was able to bind the antibodies specifically. This peptide was also shown by competitive inhibition assay to...

International audienceMechanisms of tumor immune escape are quite diverse and require specific ap... more International audienceMechanisms of tumor immune escape are quite diverse and require specific approaches for their exploration in syngeneic tumor models. In several human malignancies, galectin-9 (gal-9) is suspected to contribute to the immune escape. However, in contrast with what has been done for the infiltrating cells, the contribution of gal-9 produced by malignant cells has never been demonstrated in an animal model. Therefore, we derived isogenic clones—either positive or negative for gal-9—from the MB49 murine bladder carcinoma cell line. A progressive and consistent reduction of tumor growth was observed when gal-9-KO cells were subjected to serial transplantations into syngeneic mice. In contrast, tumor growth was unaffected during parallel serial transplantations into nude mice, thus linking tumor inhibition to the enhancement of the immune response against gal-9-KO tumors. This stronger immune response was at least in part explained by changing patterns of response to ...

<b>Copyright information:</b>Taken from "Biological characterization of two xeno... more <b>Copyright information:</b>Taken from "Biological characterization of two xenografts derived from human CUPs (carcinomas of unknown primary)"http://www.biomedcentral.com/1471-2407/7/225BMC Cancer 2007;7():225-225.Published online 18 Dec 2007PMCID:PMC2241840. : microvillosities; : large vacuole suggestive of aberrant autophagy.

<b>Copyright information:</b>Taken from "Biological characterization of two xeno... more <b>Copyright information:</b>Taken from "Biological characterization of two xenografts derived from human CUPs (carcinomas of unknown primary)"http://www.biomedcentral.com/1471-2407/7/225BMC Cancer 2007;7():225-225.Published online 18 Dec 2007PMCID:PMC2241840. Panel A : surgical specimen (× 200). Panel B: xenografted tumor (× 100). Note that specific staining is mainly associated with the plasma membrane of malignant cells.

Chemical Science, 2018

FRET and rolling circle amplification outperform RT-qPCR for microRNA diagnostics in clinical sam... more FRET and rolling circle amplification outperform RT-qPCR for microRNA diagnostics in clinical samples.

Anticancer research

Aberrant methylation of tumor suppressor gene (TSG) promoters has been extensively investigated i... more Aberrant methylation of tumor suppressor gene (TSG) promoters has been extensively investigated in nasopharyngeal carcinomas (NPC) from South East Asia but not from North Africa. The methylation status of p16, deleted in lung and esophageal cancer (DLEC1), zinc finger, MYND-type containing 10 (BLU) and E-cadherin gene promoters was investigated in 44 Tunisian NPC biopsies and three NPC xenografts, by methylation-specific PCR (MSP) combined with a quantitative assessment of some of the samples. The frequencies of aberrant promoter methylation were similar to previous figures reported for Asian series: p16 27/44 (65%), DLEC1 38/44 (86.3%), BLU 15/44 (34.1%) and E-cadherin 35/44 (79.5%). Although in other malignancies, aberrant promoter hypermethylation increases with patient age, it was at the same high frequency in the juvenile and adult forms of Tunisian NPCs. However, there was a strong association between aberrant methylation of E-cadherin promoter and lymph node invasion (p < ...

Nature Communications, 2021

Nasopharyngeal cancer (NPC), endemic in Southeast Asia, lacks effective diagnostic and therapeuti... more Nasopharyngeal cancer (NPC), endemic in Southeast Asia, lacks effective diagnostic and therapeutic strategies. Even in high-income countries the 5-year survival rate for stage IV NPC is less than 40%. Here we report high somatostatin receptor 2 (SSTR2) expression in multiple clinical cohorts comprising 402 primary, locally recurrent and metastatic NPCs. We show that SSTR2 expression is induced by the Epstein–Barr virus (EBV) latent membrane protein 1 (LMP1) via the NF-κB pathway. Using cell-based and preclinical rodent models, we demonstrate the therapeutic potential of SSTR2 targeting using a cytotoxic drug conjugate, PEN-221, which is found to be superior to FDA-approved SSTR2-binding cytostatic agents. Furthermore, we reveal significant correlation of SSTR expression with increased rates of survival and report in vivo uptake of the SSTR2-binding 68Ga-DOTA-peptide radioconjugate in PET-CT scanning in a clinical trial of NPC patients (NCT03670342). These findings reveal a key role ...

Consistent high concentration of the viral microRNA

Journal of Virology

A family of mRNAs that are transcribed rightward through the BamHI A fragment have been detected ... more A family of mRNAs that are transcribed rightward through the BamHI A fragment have been detected in C15, a nasopharyngeal carcinoma (NPC) which has been passaged in nude mice. Northern (RNA) blot hybridizations indicate that these RNAs are also expressed in three other NPCs which have been established in nude mice and in an NPC obtained at biopsy. Moreover, hybridization in situ detected transcription from BamHI A in 12 NPCs and 1 Epstein-Barr virus (EBV)-containing carcinoma of the parotid gland. In each case, transcription was detected in all of the malignant epithelial cells. Transcription was not detected in two cases of EBV-positive lymphoma biopsies by in situ hybridization nor in latently infected EBV-positive lymphoblastoid cell lines by Northern blot hybridization. The consistent transcription of these sequences in latently infected epithelial malignancy but not in lymphoid cells suggests that this viral function is associated with latent EBV infection of epithelial cells. ...

ACS Sensors

The quantification of very low concentrations of circulating tumor DNA (ctDNA) biomarkers from li... more The quantification of very low concentrations of circulating tumor DNA (ctDNA) biomarkers from liquid biopsies has become an important requirement for clinical diagnostics and personalized medicine. In particular, the simultaneous detection of wild-type dsDNA and their cancer-related counterparts presenting single point mutations with simple, sensitive, specific, and reproducible technologies is paramount for ctDNA assays in clinical practice. Here, we present the development and evaluation of an amplified dsDNA assay based on a combination of isothermal rolling circle amplification (RCA) and time-gated Förster resonance energy transfer (TG-FRET) between a Tb donor and two dye (Cy3.5 and Cy5.5) acceptors. The RCA-FRET assay is free of washing and separation steps and can quantify both wild type and mutated (V600E) dsDNA in the BRAF gene from a single sample in the 75 fM to 4.5 pM (4.5x105 to 2.7x107 copies) concentration range. The assay includes all steps from denaturation of the dsDNA targets to the final duplexed quantification of wild-type and mutated targets. High assay performance at different dsDNA sequence lengths and high target specificity even in the presence of a large excess of non-specific cell-free DNA from human plasma samples demonstrated the applicability to clinical samples. The RCA-FRET single-point-mutation sensor has the potential to become an important complementary technique for analyzing liquid biopsies in advanced cancer diagnostics.

Cellular Oncology

Purpose: Head and neck squamous cell carcinoma (HNSCC) is one of the most common cancers. Concurr... more Purpose: Head and neck squamous cell carcinoma (HNSCC) is one of the most common cancers. Concurrent radio-chemotherapy is the standard of care for advanced tumors. However, there is still a need for more efficient treatments with less secondary effects, resulting from high doses. Therefore, we undertook to explore the therapeutic potential of ternary combinations-bringing together irradiation, cis-platinum and a TLR3 agonist, poly(I:C) with aim to reduce dosage of each treatment. This approach is based on our previous studies showing a selective cytotoxic effect of TLR3 agonists against malignant cells when it is combined with other anti-neoplastic agents. Methods: We have explored the cell survival of the head and neck cancer cells (Detroit 562, FaDu, SQ20B and Cal27) by MTT and caspase 3/7 assay. The radiosensitization effect of poly(I:C) and cisplatin treatment was shown by western blot, cell cycle analysis, ROS determination and qPCR. Results: We have shown here that the combination of poly(I:C) and cisplatin can downregulate cIAP2 and survivin expression, reduce cell survival, induce anti-apoptotic gene expression and apoptosis, generate ROS formation and cause G2/M phase arrest in HNSCC cell lines. Conclusions: Our results show that poly(I:C) and cisplatin combination therapy reduces cancer cell survival and induces radiosensitivity in HNSCC cell lines thus providing a rationale for the development of a novel strategy in head and neck cancer treatment.

Laboratory investigation; a journal of technical methods and pathology, Jan 16, 2018

Epstein-Barr virus (EBV) infects more than 90% of the adult human population. Undifferentiated na... more Epstein-Barr virus (EBV) infects more than 90% of the adult human population. Undifferentiated nasopharyngeal carcinoma (NPC) is common in Southeast Asia, with a particularly high incidence among southern Chinese. The EBV genome can be detected in practically all cancer cells in undifferentiated NPC. The role of EBV in pathogenesis of undifferentiated NPC remains elusive. NPC cell lines are known to be difficult to establish in culture. The EBV+ve NPC cell lines, even if established in culture, rapidly lost their EBV episomes upon prolonged propagation. At present, the C666-1 NPC cell line, which is defective in lytic EBV reactivation, is the only EBV+ve NPC cell line available for NPC and EBV research. The need to establish new and representative NPC cell lines is eminent for NPC and EBV research. In this study, we report the use of the Rho-associated kinase inhibitor (Y-27632) has facilitated the establishment of a new EBV+ve NPC cell line from an earlier established NPC xenograft...

Cancers, Jan 6, 2018

The presence of the Epstein-Barr virus (EBV)-encoded nuclear antigen-1 (EBNA1) protein in all EBV... more The presence of the Epstein-Barr virus (EBV)-encoded nuclear antigen-1 (EBNA1) protein in all EBV-carrying tumours constitutes a marker that distinguishes the virus-associated cancer cells from normal cells and thereby offers opportunities for targeted therapeutic intervention. EBNA1 is essential for viral genome maintenance and also for controlling viral gene expression and without EBNA1, the virus cannot persist. EBNA1 itself has been linked to cell transformation but the underlying mechanism of its oncogenic activity has been unclear. However, recent data are starting to shed light on its growth-promoting pathways, suggesting that targeting EBNA1 can have a direct growth suppressing effect. In order to carry out its tasks, EBNA1 interacts with cellular factors and these interactions are potential therapeutic targets, where the aim would be to cripple the virus and thereby rid the tumour cells of any oncogenic activity related to the virus. Another strategy to target EBNA1 is to i...