Arif Hussain - Academia.edu (original) (raw)

Papers by Arif Hussain

The Journal of Biological Chemistry, 1999

We report the cloning and characterization of a DNA damage-inducible (DDI) transcript DDI A121. T... more We report the cloning and characterization of a DNA damage-inducible (DDI) transcript DDI A121. The fulllength human DDI A121 cDNA contains an open reading frame of 113 amino acids, corresponding to a protein of 12.7 kDa. The deduced amino acid sequence of A121 shows high homology to the yeast translation initiation factor (eIF) sui1 and also exhibits perfect identity to the partial sequence of recently purified human eIF1. Expression of human A121 corrected the mutant sui1 phenotype in yeast, demonstrating that human A121 encodes a bona fide translation initiation factor that is equivalent to yeast sui1p. The mammalian A121/SUI1 gene exhibits two transcripts (1.35 kilobases and 0.65 kilobases) containing a common coding region but differing in their 3-untranslated region. The long and short A121/SUI1 mRNAs are differentially regulated by genotoxic and endoplasmic reticulum stress. The genotoxic stress induction of A121/SUI1 mRNA is conserved in both humans and rodents and occurs in a p53-independent manner. Our identification of a stress-inducible cDNA that encodes eIF1 suggests that modulation of translation initiation appears to occur during cellular stress and may represent an important adaptive response to genotoxic as well as endoplasmic reticulum stress.

Cancer Research, Jul 15, 1993

The human p53-binding protein murine double minute 2 (MDM2) is believed to function as a negative... more The human p53-binding protein murine double minute 2 (MDM2) is believed to function as a negative regulator of p53. The MDM2 gene was cloned and sequenced only recently and was found to be amplified in a variety of sarcomas. Although mutations in thep5J gene have been shown to occur in human breast carcinoma (HBC), no information is available on MDM2 gene expression in HBC. In this study we report for the first time that the MDM2 gene is differentially expressed in HBC. Our results dem onstrate a correlation between the estrogen receptor (ER) status and the MDM2 mRNA levels. In contrast to the ER-negative cell lines, all the ER-positive cell lines were found to express higher levels of\lDM2 mRNA. ER-positive ZR-75 cells express 30-fold higher levels of MDM2 mRNA than does the ER-negative cell line Hs578T. Estrogen enhanced albeit modestly the MDM2 mRNA levels in ER-positive MCF-7 cells. Estrogen enhancement of MDM2 mRNA levels was also observed in ER-negative MDA-MB-231 cells transfected with functional ERs. Our data thus sug gest that estrogen may play an important role in HBC growth stimulation by modulating the expression of MDM2, which in turn may inactivate the p53 function.

Oncogene, May 1, 2002

Thapsigargin (TG), by inducing perturbations in cellular Ca 2+ homeostasis, has been shown to ind... more Thapsigargin (TG), by inducing perturbations in cellular Ca 2+ homeostasis, has been shown to induce apoptosis. The molecular mechanisms of Ca 2+ perturbation-induced apoptosis are not fully understood. In this study, we demonstrate for the ®rst time that TG-mediated perturbations in Ca 2+ homeostasis are coupled with activation of the death receptor 5 (DR5)-dependent apoptotic pathway in human cancer cells. TG selectively upregulated DR5 but had no eect on the expression of the other TRAIL receptor, DR4. TG also upregulated the expression of the DR5 ligand TRAIL (tumor necrosis factor-related apoptosis inducing ligand), albeit in a celltype speci®c manner. TG-induced apoptosis has been shown to be associated with activation of the mitochondrial pathway. We found that TG upregulation of DR5 and TRAIL was coupled with caspase 8 activation and Bid cleavage, suggesting that the TG-regulated DR5 pathway could be linked to the mitochondrial pathway. TG enhanced not only DR5 mRNA stability but also increased induction of the DR5 genomic promoterreporter gene. The TG-induced increase in DR5 expression appeared to occur as a consequence of TGinduced endoplasmic reticulum (ER) Ca 2+ pool depletion. Thus, we report our novel ®ndings that ER Ca 2+ pool depletion-induced apoptotic signals are mediated, at least in part, via a DR5-dependent apoptotic pathway and there appears to be a cross-talk between the death receptor and mitochondrial pathways.

The Prostate, 2009

BACKGROUND. Neuroendocrine differentiation and neuroendocrine carcinoma (NEC) have been linked to... more BACKGROUND. Neuroendocrine differentiation and neuroendocrine carcinoma (NEC) have been linked to androgen deprivation in prostate cancers. No previous study has directly connected neuroendocrine phenotypes to chemotherapy. The pathogenesis of prostatic NEC has not yet been determined. METHODS. Using the transgenic adenocarcinoma of mouse prostate (TRAMP) model, we studied tumor progression after hormone ablation (castration) and/or chemotherapy (docetaxel), and analyzed the incidence of NEC as a function of the anti-tumor therapies. Non-treated mice were used as controls. Protein expressions in tumor tissues were analyzed by Western blots and immunohistochemistry. RESULTS. Although all animals developed prostate cancer, no NEC was found in control mice. However, over 30% of the mice that received an anti-tumor therapy developed NEC. A similar incidence of NEC was found in the castration-only and docetaxel-only treatment groups, while a higher incidence was observed in the combined treatment (castration and docetaxel) group. The NEC-bearing mice had smaller tumors in their prostates and lived longer than mice with adenocarcinoma (ADC-only). However, NEC tumors had a higher proliferative index and greater potential for metastasis and drug-resistance, as evidenced by significantly higher expression levels of PCNA, S100A4, and Pgp, but lower levels of E-cadherin. SV40 T-antigen was highly expressed in both NEC and ADC tumors. CONCLUSIONS. Stress induced by anti-cancer treatments may play a role in NEC development. Although NEC and ADC differ in their expressions of many proteins, a high level of SV40 T-antigen in both tumor types suggest a common progenitor.

Gene, Oct 3, 1995

Three differently sized mRNAs are expressed from each of two DHFR (encoding dihydrofolate reducta... more Three differently sized mRNAs are expressed from each of two DHFR (encoding dihydrofolate reductase) alleles present in the Chinese hamster lung (CHL) cell line, DC-3F. The relative abundancy of the transcripts produced from each allele differs dramatically as a result of differential utilization of the multiple poly(A) sites present in the DHFR gene and a genetic polymorphism located within the third poly(A) signal of one allele. We sought to determine whether such differences in polyadenylation affect the steady-state levels of DHFR mRNAs expressed from either allele and, in a more general sense, to ask whether differences in 3' end RNA processing in a gene containing multiple poly(A) sites affects the final level of gene expression. An SV40 promoter-based transient expression system producing chimeric cat::DHFR transcripts was developed to regenerate the in vivo mRNA polyadenylation patterns associated with each of the two DHFR alleles. The results demonstrate that the total amount of polyadenylated RNA expressed from each of these constructs in vitro is the same regardless of the differential utilization of the poly(A) signals that occurs between them. Moreover, measurement of the individual turnover rates of the DHFR mRNAs expressed in vivo from each allele, as determined by pulse-chase labeling and actinomycin D inhibition studies, revealed no significant allele-specific differences in transcript half-lives. Finally, measuring the steady-state levels of DHFR poly(A)+mRNA in parental DC-3F cells demonstrated that bc,th alleles are expressed to the same extent during normal growth. Thus, even though dramatic allele-specific differences in 3' end processing of DHFR transcripts occur in vivo, such differences do not appear to influence the steady-state levels of DHFR gene expression.

Journal of Biological Chemistry

In an effort to better understand the preferential resistance to actinomycin D displayed by the m... more In an effort to better understand the preferential resistance to actinomycin D displayed by the multidrug-resistant Chinese hamster lung cell line DC-3F/ADX, we have cloned from those cells a number of cDNAs representing p-glycoprotein gene transcripts. Of the 12 clones isolated, all represent pgp1 transcripts and one, pADX165, contains a 4304-base pair insert with an open reading frame encoding a 1276-amino acid protein that is the homolog of the mouse mdr3/mdr1a gene product. A domain by domain comparison of this protein with p-glycoproteins capable of supporting multidrug resistance, i.e. human mdr1, mouse mdr1/mdr1b, and mouse mdr3/mdr1a, shows that, in addition to the ATP binding sites, the second, fourth, and eleventh transmembrane domains and the four small intracellular loops, IC-1, IC-2, IC-4, and IC-5, are highly conserved and are therefore likely to be important for the maintenance of p-glycoprotein function. Of the remaining 11 cDNA clones, 9 were found to be truncated v...

PURPOSE Despite long-term androgen ablation (AA) and external beam radiation therapy, more than 5... more PURPOSE Despite long-term androgen ablation (AA) and external beam radiation therapy, more than 50% of patients with high-risk prostate cancer fail biochemically. We instituted a phase II protocol in attempts to improve on these results by adding a brachytherapy boost, designed to further increase the radiation dose to the prostate, and docetaxel chemotherapy to address possible subclinical systemic disease. The following describes the initial toxicity data of the first 15 patients enrolled on a prospective institutional trial. METHOD AND MATERIALS Between 2006-2008, 15 patients with high risk prostate cancer (Gleason score ò 8, PSA ò 20, or clinical T3 disease; or at least 2 of the following: Gleason 7, PSA 15-20, clinical T2c) were enrolled on a trial consisting of 2 years of AA, bone-marrow sparing pelvic IMRT to 45Gy, Cs-131 brachytherapy boost to 85Gy, and 4 cycles of adjuvant docetaxel chemotherapy at 75mg/m2 Q3weeks along with prednisone. Patients were started on prophylactic...

Journal of the College of Physicians and Surgeons--Pakistan: JCPSP

A 27 days old newborn with critical pulmonary valve stenosis remained prostaglandin (PGE(1)) depe... more A 27 days old newborn with critical pulmonary valve stenosis remained prostaglandin (PGE(1)) dependent for 2 weeks after successful balloon valvuloplasty. Only the introduction of Phentolamine in his medication regimen, allowed PGE(1) to be weaned off within days of this therapy. The medication was continued for 4 days and replaced by angiotensin converting enzyme inhibitor (Captopril). Few weeks after the discharge, the patient remained clinically stable with acceptable saturation.

Evidence-Based Complementary and Alternative Medicine, 2015

Sulforaphane (SFN) may hinder carcinogenesis by altering epigenetic events in the cells; however,... more Sulforaphane (SFN) may hinder carcinogenesis by altering epigenetic events in the cells; however, its molecular mechanisms are unclear. The present study investigates the role of SFN in modifying epigenetic events in human cervical cancer cells, HeLa. HeLa cells were treated with SFN (2.5 M) for a period of 0, 24, 48, and 72 hours for all experiments. After treatment, expressions of DNMT3B, HDAC1, RAR , CDH1, DAPK1, and GSTP1 were studied using RT-PCR while promoter DNA methylation of tumor suppressor genes (TSGs) was studied using MS-PCR. Inhibition assays of DNA methyl transferases (DNMTs) and histone deacetylases (HDACs) were performed at varying time points. Molecular modeling and docking studies were performed to explore the possible interaction of SFN with HDAC1 and DNMT3B. Time-dependent exposure to SFN decreases the expression of DNMT3B and HDAC1 and significantly reduces the enzymatic activity of DNMTs and HDACs. Molecular modeling data suggests that SFN may interact directly with DNMT3B and HDAC1 which may explain the inhibitory action of SFN. Interestingly, timedependent reactivation of the studied TSGs via reversal of methylation in SFN treated cells correlates well with its impact on the epigenetic alterations accumulated during cancer development. Thus, SFN may have significant implications for epigenetic based therapy.

Cancer research, Jan 15, 1989

The response of class I major histocompatibility complex antigen expression to in vitro administr... more The response of class I major histocompatibility complex antigen expression to in vitro administration of interferon and tumor necrosis factor alpha (TNF-alpha) was measured using class I major histocompatibility complex-deficient small cell lung cancer cell lines. Significant induction also was observed using gamma interferon (IFN-gamma) alone, whereas TNF-alpha alone yielded only modest induction. Classic small cell lung cancer cell lines NCI-H146 and NCI-H209 best demonstrated synergistic HLA and beta 2-microglobulin antigen induction with IFN-gamma and TNF-alpha with the following dose schedule: 3-6 days of TNF-alpha (200 units/ml) followed by 48 h of IFN-gamma (100 IU/ml). Induction was quantitated using an 125I-Protein A radioimmunoassay. Synergistic induction of the HLA and beta 2-microglobulin surface antigens on NCI-H146 was also possible with alpha interferon and TNF-alpha but required a higher concentration of the interferon, i.e., 3-6 days of TNF-alpha (200 units/ml) fol...

Seminars in oncology, 2001

An increasingly important issue in the management of prostate cancer is the occurrence of biochem... more An increasingly important issue in the management of prostate cancer is the occurrence of biochemical failure (ie, increasing serum prostate-specific antigen [PSA] levels) in patients with clinically localized prostate cancer who initially underwent definitive treatments with curative intent (prostatectomy and/or radiation therapy). This pilot trial evaluated chemotherapy followed by hormone therapy for a defined period in patients with biochemical (and possibly clinical) recurrence after initial local therapies for localized/locally advanced prostate cancer. Patients who developed increasing PSA > 4 ng/mL after initial prostatectomy and/or radiation therapy received docetaxel, 70 mg/m(2) every 3 weeks for up to 6 courses, followed by 4 months of total androgen suppression (using a luteinizing hormone-releasing hormone agonist plus bicalutamide, 50 mg/d) and 8 months of peripheral androgen blockade (using finasteride, 5 mg/d, plus bicalutamide, 50 mg/d). Twenty-seven patients hav...

The Journal of biological chemistry, Jan 18, 1994

Resistance to the intracellular Ca2+ pump inhibitor thapsigargin (TG) is associated with overexpr... more Resistance to the intracellular Ca2+ pump inhibitor thapsigargin (TG) is associated with overexpression of both Ca2+ transport ATPase and the multidrug resistance (mdr) transporter P-glycoprotein (pgp). This is supported by increased resistance to TG following transfection of a functional pgp1 cDNA, and reversal of TG resistance with known inhibitors of pgp function. However, pgp is unlikely to represent the only mechanism of resistance to TG. Cell lines selected for high levels of resistance to TG (250-fold) show only a 3.7-fold increase in pgp expression and a 2-fold increase in cross-resistance to other drugs of the mdr class. Overexpression of endogenous Ca2+ transport ATPase may represent a second mechanism of resistance to TG. Increased Ca2+ ATPase expression (3-fold) is seen in cells made resistant to TG, and TG resistance increases with the transfection of a specific Ca2+ ATPase cDNA into DC-3F cells. If these transfectants are then made resistant to TG, both the endogenous ...

Oncology Reports, 2015

There has been increasing evidence that numerous bioactive dietary agents can hamper the process ... more There has been increasing evidence that numerous bioactive dietary agents can hamper the process of carcinogenesis by targeting epigenetic alterations including DNA methylation. This therapeutic approach is considered as a significant goal for cancer therapy due to the reversible nature of epigenetic-mediated gene silencing and warrants further attention. One such dietary agent, green tea catechin, (-)-epigallocatechin-3-gallate (EGCG) has been shown to modulate many cancer-related pathways. Thus, the present study was designed to investigate the role of EGCG as an epigenetic modifier in HeLa cells. DNA methyltransferase (DNMT) and histone deacetylase (HDAC) inhibition assays were conducted, and the transcription levels of DNMT3B and HDAC1 were assessed by enzymatic activity assay and RT-PCR, respectively. Furthermore, we studied the binding interaction of EGCG with DNMT3B and HDAC1 by molecular modeling as well as promoter DNA methylation and expression of retinoic acid receptor-β (RARβ), cadherin 1 (CDH1) and death-associated protein kinase-1 (DAPK1) in EGCG-treated HeLa cells by RT-PCR and MS-PCR. In the present study, time-dependent EGCG-treated HeLa cells were found to have a significant reduction in the enzymatic activity of DNMT and HDAC. However, the expression of DNMT3B was significantly decreased in a time-dependent manner whereas there was no significant change in HDAC1 expression. Molecular modeling data also supported the EGCG-mediated DNMT3B and HDAC1 activity inhibition. Furthermore, time-dependent exposure to EGCG resulted in reactivation of known tumor-suppressor genes (TSGs) in HeLa cells due to marked changes in the methylation of the promoter regions of these genes. Overall, the present study suggests that EGCG may have a significant impact on the development of novel epigenetic-based therapy.

Prostate Cancer - Original Scientific Reports and Case Studies, 2011

Oncogene, Jan 18, 2002

Thapsigargin (TG), by inducing perturbations in cellular Ca(2+) homeostasis, has been shown to in... more Thapsigargin (TG), by inducing perturbations in cellular Ca(2+) homeostasis, has been shown to induce apoptosis. The molecular mechanisms of Ca(2+) perturbation-induced apoptosis are not fully understood. In this study, we demonstrate for the first time that TG-mediated perturbations in Ca(2+) homeostasis are coupled with activation of the death receptor 5 (DR5)-dependent apoptotic pathway in human cancer cells. TG selectively upregulated DR5 but had no effect on the expression of the other TRAIL receptor, DR4. TG also upregulated the expression of the DR5 ligand TRAIL (tumor necrosis factor-related apoptosis inducing ligand), albeit in a cell-type specific manner. TG-induced apoptosis has been shown to be associated with activation of the mitochondrial pathway. We found that TG upregulation of DR5 and TRAIL was coupled with caspase 8 activation and Bid cleavage, suggesting that the TG-regulated DR5 pathway could be linked to the mitochondrial pathway. TG enhanced not only DR5 mRNA ...

Indian heart journal

Inadvertent and accidental epinephrine overdose might result in potentially lethal complications.... more Inadvertent and accidental epinephrine overdose might result in potentially lethal complications. We present a case of acute epinephrine toxicity resulting in acute myocardial ischemia in a young boy with combined variable immunodeficiency syndrome who developed severe allergic reaction to intravenous immunoglobulin, and was subsequently given epinephrine by mistake intravenously rather than subcutaneously. He developed significant ischemic changes in standard 12-lead electrocardiogram, transiently raised cardiac enzymes, reduced left ventricular systolic function, pulmonary edema and pulmonary hemorrhage. It is suggested that special precautionary measures should be taken regarding the dose and the route while administering epinephrine to avoid mishaps.

Journal of the College of Physicians and Surgeons--Pakistan : JCPSP, 2005

A 12-year-old boy reported in outpatient department with history of shortness of breath and dyspn... more A 12-year-old boy reported in outpatient department with history of shortness of breath and dyspnoea on moderate exertion. Physical examination was significant for bounding pulses and for a continuous murmur III/VI, best heard at the left upper sternal border. Echocardiography confirmed a large patent arterial duct with shortening fraction of 33%. He underwent successful transcatheter closure of the patent arterial, using Amplatzer duct occluder 12/10. Few hours later echocardiography revealed an unexpected, yet important depression of left ventricular systolic function with shortening fraction decreasing to 24% and then two weeks later decreasing further to 20%. At a follow-up after four months, he had improved clinically but left ventricular dysfunction still persisted with shortening fraction of 24%.

Clinical genitourinary cancer, 2006

Locally advanced prostate cancer encompasses several disease states that vary in the risk for pro... more Locally advanced prostate cancer encompasses several disease states that vary in the risk for progression and recurrence after initial treatment. Further, the optimal treatment strategies for locally advanced prostate cancer are continuing to evolve, reflecting the complex nature of this disease state. For many patients, clinical experience demonstrates that a combined approach of locally directed therapy and systemic therapy is likely to provide better long-term outcome than single-modality therapy. Randomized studies have established hormone ablation with external-beam radiation as an important form of treatment for this group of patients. However, additional progress needs to be made, particularly in the subgroup of patients with very high-risk disease features. As the optimal integration of local and systemic treatments becomes more clearly defined, the long-term prognosis for patients with high-risk locally advanced prostate cancer will improve.