Jodi Alt - Academia.edu (original) (raw)
Papers by Jodi Alt
The EMBO journal, Jan 17, 2003
Mdm2 harnesses the p53 tumor suppressor, yet loss of one Mdm2 allele in Mdm2(+/-) mice has hereto... more Mdm2 harnesses the p53 tumor suppressor, yet loss of one Mdm2 allele in Mdm2(+/-) mice has heretofore not been shown to impair tumor development. Here we report that Mdm2 haplo-insufficiency profoundly suppresses lymphomagenesis in E micro -myc transgenic mice. Mdm2(+/-)E micro -myc transgenics had greatly protracted rates of B cell lymphoma development with life spans twice that of wild-type transgenic littermates. Im paired lymphoma development was associated with drastic reductions in peripheral B cell numbers in Mdm2(+/-)E micro -myc transgenics, and primary pre-B cells from Mdm2(+/-)E micro -myc transgenics and Mdm2(+/-) littermates were extremely susceptible to spontaneous apoptosis. Loss of p53 rescued all of the effects of Mdm2 haplo-insufficiency, indicating they were p53 dependent. Furthermore, half of the lymphomas that ultimately emerged in Mdm2(+/-)E micro -myc transgenics harbored inactivating mutations in p53, and the majority overcame haplo-insufficiency by overexpre...
Oncogene, Jan 25, 2004
The tumor suppressor p19ARF inhibits Mdm2, which restricts the activity of p53. Complicated feedb... more The tumor suppressor p19ARF inhibits Mdm2, which restricts the activity of p53. Complicated feedback and control mechanisms regulate ARF, Mdm2, and p53 interactions. Here we report that ARF haploinsufficiency completely rescued the p53-dependent effects of Mdm2 haploinsufficiency on B-cell development, survival, and transformation. In contrast to Mdm2+/- B cells, Mdm2+/- B cells deficient in ARF were similar to wild-type B cells in their rates of growth and apoptosis and activation of p53. Consequently, the profoundly reduced numbers of B cells in Mdm2+/-Emu-myc transgenic mice were restored to normal levels in ARF+/-Mdm2+/-Emu-myc transgenics. Additionally, ARF+/-Mdm2+/-Emu-myc transgenics developed lymphomas at rates analogous to those observed for wild-type Emu-myc transgenics, demonstrating that loss of one allele of ARF rescued the protracted lymphoma latency in Mdm2+/-Emu-myc transgenics. Importantly, in ARF+/-Mdm2+/-Emu-myc transgenic lymphomas, p53 was inactivated at the fre...
The Journal of biological chemistry, Jan 13, 2005
Mdm2 directly regulates the p53 tumor suppressor. However, Mdm2 also has p53-independent activiti... more Mdm2 directly regulates the p53 tumor suppressor. However, Mdm2 also has p53-independent activities, and the pathways that mediate these functions are unresolved. Here we report the identification of a specific association of Mdm2 with Mre11, Nbs1, and Rad50, a DNA double strand break repair complex. Mdm2 bound to the Mre11-Nbs1-Rad50 complex in primary cells and in cells containing inactivated p53 or p14/p19ARF, a regulator of Mdm2. Further analysis revealed that Mdm2 directly bound to Nbs1 but not to Mre11 or Rad50. Amino acids 198-314 of Mdm2 were required for Mdm2/Nbs1 association, and neither the N terminus forkhead-associated and breast cancer C-terminal domains nor the C terminus Mre11 binding domain of Nbs1 mediated the interaction of Nbs1 with Mdm2. Mdm2 co-localized with Nbs1 to sites of DNA damage following gamma-irradiation. Notably, Mdm2 overexpression inhibited DNA double strand break repair, and this was independent of p53 and ARF, the alternative reading frame of the...
Oncogene, 2004
The tumor suppressor p19 ARF inhibits Mdm2, which restricts the activity of p53. Complicated feed... more The tumor suppressor p19 ARF inhibits Mdm2, which restricts the activity of p53. Complicated feedback and control mechanisms regulate ARF, Mdm2, and p53 interactions. Here we report that ARF haploinsufficiency completely rescued the p53-dependent effects of Mdm2 haploinsufficiency on B-cell development, survival, and transformation. In contrast to Mdm2 þ /À B cells, Mdm2 þ /À B cells deficient in ARF were similar to wild-type B cells in their rates of growth and apoptosis and activation of p53. Consequently, the profoundly reduced numbers of B cells in Mdm2 þ /À El-myc transgenic mice were restored to normal levels in ARF þ /À Mdm2 þ /À El-myc transgenics. Additionally, ARF þ /À Mdm2 þ /À El-myc transgenics developed lymphomas at rates analogous to those observed for wild-type El-myc transgenics, demonstrating that loss of one allele of ARF rescued the protracted lymphoma latency in Mdm2 þ /À El-myc transgenics. Importantly, in ARF þ /À Mdm2 þ /À El-myc transgenic lymphomas, p53 was inactivated at the frequency observed in lymphomas of wild-type El-myc transgenics. Collectively, these results support a model whereby the stoichiometry of Mdm2 and ARF controls apoptosis and tumor development, which should have significant implications in the treatment of malignancies that have inactivated ARF.
Cancer Cell International, 2014
The enumeration and characterization of circulating tumor cells (CTCs) in the blood of cancer pat... more The enumeration and characterization of circulating tumor cells (CTCs) in the blood of cancer patients is useful for cancer prognostic and treatment monitoring purposes. The number of CTCs present in patient blood is very low; thus, robust technologies have been developed to enumerate and characterize CTCs in patient blood samples. One of the challenges to the clinical utility of CTCs is their inherent fragility, which makes these cells very unstable during transportation and storage of blood samples. In this study we investigated Cell-Free DNA BCT™ (BCT), a blood collection device, which stabilizes blood cells in a blood sample at room temperature (RT) for its ability to stabilize CTCs at RT for an extended period of time. Blood was drawn from each donor into K3EDTA tube, CellSave tube and BCT. Samples were then spiked with breast cancer cells (MCF-7), transported and stored at RT. Spiked cancer cells were counted using the Veridex CellSearch™ system on days 1 and 4. The effect of storage on the stability of proteins and nucleic acids in the spiked cells isolated from K3EDTA tube and BCT was determined using fluorescence staining and confocal laser scanning microscopy. MCF-7 cell recovery significantly dropped when transported and stored in K3EDTA tubes. However, in blood collected into CellSave tubes and BCTs, the MCF-7 cell count was stable up to 4 days at RT. Epithelial cell adhesion molecule (EpCAM) and cytokeratin (CK) in MCF-7 cells isolated from BCTs was stable at RT for up to 4 days, whereas in MCF-7 cells isolated from K3EDTA blood showed reduced EpCAM and CK protein expression. Similarly, BCTs stabilized c-fos and cyclin D1 mRNAs as compared to K3EDTA tubes. Cell-Free DNA™ BCT blood collection device preserves and stabilizes CTCs in blood samples for at least 4 days at RT. This technology may facilitate the development of new non-invasive diagnostic and prognostic methodologies for CTC enumeration as well as characterization.
Mol Diagn Ther , 2014
Background Messenger RNA (mRNA) expression levels in blood cells are important in disease diagno... more Background Messenger RNA (mRNA) expression levels
in blood cells are important in disease diagnosis, prognosis
and biomarker discovery research. Accurate measurements
of intracellular mRNA levels in blood cells depend upon
several pre-analytical factors, including delays in RNA
extraction from blood after phlebotomy. Dramatic changes
in mRNA expression levels caused by delays in blood
sample processing may render such samples unsuitable for
gene expression analysis.
Objectives This study was conducted to evaluate a blood
collection tube, cell-free RNA-BCT (RNA-BCT), for its
ability to stabilize mRNA expression level in blood cells
post-phlebotomy using indicator mRNAs in reverse transcription
quantitative real-time PCR (RT-qPCR) assays.
Methods Blood samples from presumed healthy donors
were drawn into both RNA-BCT and K3EDTA tubes and
maintained at room temperature (18–22 C). The samples
were processed to obtain white blood cells (WBCs) at days
0, 1, 2 and 3. Total cellular RNA was extracted from
WBCs and mRNA concentrations were quantified by RTqPCR
for glyceraldehyde-3-phosphate dehydrogenase
(GAPDH), c-fos, and p53 transcripts.
Results While blood cells isolated from K3EDTA tubes
showed significant changes in cellular mRNA
concentrations for GAPDH, c-fos, and p53, these mRNAs
concentrations were stable in blood drawn into RNA-BCT.
Conclusion The reagent in the RNA-BCT device stabilizes
cellular mRNA concentrations for GAPDH, c-fos and
p53 for at least three days at room temperature.
The EMBO journal, Jan 17, 2003
Mdm2 harnesses the p53 tumor suppressor, yet loss of one Mdm2 allele in Mdm2(+/-) mice has hereto... more Mdm2 harnesses the p53 tumor suppressor, yet loss of one Mdm2 allele in Mdm2(+/-) mice has heretofore not been shown to impair tumor development. Here we report that Mdm2 haplo-insufficiency profoundly suppresses lymphomagenesis in E micro -myc transgenic mice. Mdm2(+/-)E micro -myc transgenics had greatly protracted rates of B cell lymphoma development with life spans twice that of wild-type transgenic littermates. Im paired lymphoma development was associated with drastic reductions in peripheral B cell numbers in Mdm2(+/-)E micro -myc transgenics, and primary pre-B cells from Mdm2(+/-)E micro -myc transgenics and Mdm2(+/-) littermates were extremely susceptible to spontaneous apoptosis. Loss of p53 rescued all of the effects of Mdm2 haplo-insufficiency, indicating they were p53 dependent. Furthermore, half of the lymphomas that ultimately emerged in Mdm2(+/-)E micro -myc transgenics harbored inactivating mutations in p53, and the majority overcame haplo-insufficiency by overexpre...
Oncogene, Jan 25, 2004
The tumor suppressor p19ARF inhibits Mdm2, which restricts the activity of p53. Complicated feedb... more The tumor suppressor p19ARF inhibits Mdm2, which restricts the activity of p53. Complicated feedback and control mechanisms regulate ARF, Mdm2, and p53 interactions. Here we report that ARF haploinsufficiency completely rescued the p53-dependent effects of Mdm2 haploinsufficiency on B-cell development, survival, and transformation. In contrast to Mdm2+/- B cells, Mdm2+/- B cells deficient in ARF were similar to wild-type B cells in their rates of growth and apoptosis and activation of p53. Consequently, the profoundly reduced numbers of B cells in Mdm2+/-Emu-myc transgenic mice were restored to normal levels in ARF+/-Mdm2+/-Emu-myc transgenics. Additionally, ARF+/-Mdm2+/-Emu-myc transgenics developed lymphomas at rates analogous to those observed for wild-type Emu-myc transgenics, demonstrating that loss of one allele of ARF rescued the protracted lymphoma latency in Mdm2+/-Emu-myc transgenics. Importantly, in ARF+/-Mdm2+/-Emu-myc transgenic lymphomas, p53 was inactivated at the fre...
The Journal of biological chemistry, Jan 13, 2005
Mdm2 directly regulates the p53 tumor suppressor. However, Mdm2 also has p53-independent activiti... more Mdm2 directly regulates the p53 tumor suppressor. However, Mdm2 also has p53-independent activities, and the pathways that mediate these functions are unresolved. Here we report the identification of a specific association of Mdm2 with Mre11, Nbs1, and Rad50, a DNA double strand break repair complex. Mdm2 bound to the Mre11-Nbs1-Rad50 complex in primary cells and in cells containing inactivated p53 or p14/p19ARF, a regulator of Mdm2. Further analysis revealed that Mdm2 directly bound to Nbs1 but not to Mre11 or Rad50. Amino acids 198-314 of Mdm2 were required for Mdm2/Nbs1 association, and neither the N terminus forkhead-associated and breast cancer C-terminal domains nor the C terminus Mre11 binding domain of Nbs1 mediated the interaction of Nbs1 with Mdm2. Mdm2 co-localized with Nbs1 to sites of DNA damage following gamma-irradiation. Notably, Mdm2 overexpression inhibited DNA double strand break repair, and this was independent of p53 and ARF, the alternative reading frame of the...
Oncogene, 2004
The tumor suppressor p19 ARF inhibits Mdm2, which restricts the activity of p53. Complicated feed... more The tumor suppressor p19 ARF inhibits Mdm2, which restricts the activity of p53. Complicated feedback and control mechanisms regulate ARF, Mdm2, and p53 interactions. Here we report that ARF haploinsufficiency completely rescued the p53-dependent effects of Mdm2 haploinsufficiency on B-cell development, survival, and transformation. In contrast to Mdm2 þ /À B cells, Mdm2 þ /À B cells deficient in ARF were similar to wild-type B cells in their rates of growth and apoptosis and activation of p53. Consequently, the profoundly reduced numbers of B cells in Mdm2 þ /À El-myc transgenic mice were restored to normal levels in ARF þ /À Mdm2 þ /À El-myc transgenics. Additionally, ARF þ /À Mdm2 þ /À El-myc transgenics developed lymphomas at rates analogous to those observed for wild-type El-myc transgenics, demonstrating that loss of one allele of ARF rescued the protracted lymphoma latency in Mdm2 þ /À El-myc transgenics. Importantly, in ARF þ /À Mdm2 þ /À El-myc transgenic lymphomas, p53 was inactivated at the frequency observed in lymphomas of wild-type El-myc transgenics. Collectively, these results support a model whereby the stoichiometry of Mdm2 and ARF controls apoptosis and tumor development, which should have significant implications in the treatment of malignancies that have inactivated ARF.
Cancer Cell International, 2014
The enumeration and characterization of circulating tumor cells (CTCs) in the blood of cancer pat... more The enumeration and characterization of circulating tumor cells (CTCs) in the blood of cancer patients is useful for cancer prognostic and treatment monitoring purposes. The number of CTCs present in patient blood is very low; thus, robust technologies have been developed to enumerate and characterize CTCs in patient blood samples. One of the challenges to the clinical utility of CTCs is their inherent fragility, which makes these cells very unstable during transportation and storage of blood samples. In this study we investigated Cell-Free DNA BCT™ (BCT), a blood collection device, which stabilizes blood cells in a blood sample at room temperature (RT) for its ability to stabilize CTCs at RT for an extended period of time. Blood was drawn from each donor into K3EDTA tube, CellSave tube and BCT. Samples were then spiked with breast cancer cells (MCF-7), transported and stored at RT. Spiked cancer cells were counted using the Veridex CellSearch™ system on days 1 and 4. The effect of storage on the stability of proteins and nucleic acids in the spiked cells isolated from K3EDTA tube and BCT was determined using fluorescence staining and confocal laser scanning microscopy. MCF-7 cell recovery significantly dropped when transported and stored in K3EDTA tubes. However, in blood collected into CellSave tubes and BCTs, the MCF-7 cell count was stable up to 4 days at RT. Epithelial cell adhesion molecule (EpCAM) and cytokeratin (CK) in MCF-7 cells isolated from BCTs was stable at RT for up to 4 days, whereas in MCF-7 cells isolated from K3EDTA blood showed reduced EpCAM and CK protein expression. Similarly, BCTs stabilized c-fos and cyclin D1 mRNAs as compared to K3EDTA tubes. Cell-Free DNA™ BCT blood collection device preserves and stabilizes CTCs in blood samples for at least 4 days at RT. This technology may facilitate the development of new non-invasive diagnostic and prognostic methodologies for CTC enumeration as well as characterization.
Mol Diagn Ther , 2014
Background Messenger RNA (mRNA) expression levels in blood cells are important in disease diagno... more Background Messenger RNA (mRNA) expression levels
in blood cells are important in disease diagnosis, prognosis
and biomarker discovery research. Accurate measurements
of intracellular mRNA levels in blood cells depend upon
several pre-analytical factors, including delays in RNA
extraction from blood after phlebotomy. Dramatic changes
in mRNA expression levels caused by delays in blood
sample processing may render such samples unsuitable for
gene expression analysis.
Objectives This study was conducted to evaluate a blood
collection tube, cell-free RNA-BCT (RNA-BCT), for its
ability to stabilize mRNA expression level in blood cells
post-phlebotomy using indicator mRNAs in reverse transcription
quantitative real-time PCR (RT-qPCR) assays.
Methods Blood samples from presumed healthy donors
were drawn into both RNA-BCT and K3EDTA tubes and
maintained at room temperature (18–22 C). The samples
were processed to obtain white blood cells (WBCs) at days
0, 1, 2 and 3. Total cellular RNA was extracted from
WBCs and mRNA concentrations were quantified by RTqPCR
for glyceraldehyde-3-phosphate dehydrogenase
(GAPDH), c-fos, and p53 transcripts.
Results While blood cells isolated from K3EDTA tubes
showed significant changes in cellular mRNA
concentrations for GAPDH, c-fos, and p53, these mRNAs
concentrations were stable in blood drawn into RNA-BCT.
Conclusion The reagent in the RNA-BCT device stabilizes
cellular mRNA concentrations for GAPDH, c-fos and
p53 for at least three days at room temperature.