Histone Deacetylase Inhibitory Approaches for the Management of Osteoarthritis

This commentary highlights the article by Makki and Haqqi that proposes the use of vorinostat as a therapeutic agent for the management of osteoarthritis.

Abstract LB-102: A pro-proliferative function of centriole duplication regulator, polo-like kinase-4 in human melanoma

Malignant melanoma is one of the deadliest forms of skin cancer that remains resistant to existing therapeutic strategies. According to the SEER (Surveillance, Epidemiology, and End Results) program database of the National Cancer Institute, the 5-year survival rate for metastatic melanoma is a dismal 16%. Further, of the seven most common cancers in the USA, melanoma is the only neoplasm with constantly increasing incidence. Therefore, it is important to intensify our efforts to better-understand the genetics and biology of melanoma. This may lead to development of novel targets and biomarkers for management of this hard-to-treat neoplasm. This study was undertaken to determine the role and potential significance of polo-like kinase 4 (PLK4) in human melanoma. PLK4 is a serine/threonine kinase that has been shown to localize to centrioles and regulate centriole duplication during the cell cycle. While the potential role of PLK4 in cancer is beginning to be appreciated, there are evidence for its function as a tumor suppressor as well as tumor promoter. However, the role of PLK4 in melanoma is not known. Here, we employed in vitro and ex vivo experiments to determine the role of PLK4 in melanoma. Our data demonstrated that PLK4 was significantly overexpressed, both at mRNA and protein levels in human melanoma cells viz. A375, Hs294T, G361, 451Lu; when compared to the normal human epidermal melanocytes (NHEM). We also found a significant increase in PLK4 immunostaining in clinical melanoma tissues, compared to normal skin and nevus tissues. Further, treatment of melanoma cells with a selective small molecule PLK4 inhibitor, centrinone-B, was found to cause a significant decrease in the cell growth/viability and clonogenic survival in multiple melanoma cell lines. The observed anti-proliferative effects of centrinone-B were found to be accompanied with i) a G0/G1 phase arrest of cell cycle, and ii) induction of apoptosis, in human melanoma cells. Taken together, our study suggests a pro-proliferative role of PLK4 in human melanoma. Additional studies are ongoing in our laboratory to determine the functional significance of PLK4 in melanoma. We suggest that PLK4 should be further evaluated as a potential ‘druggable target’ and biomarker, for the management of melanoma.

Citation Format: Maria Shabbir, Minakshi Nihal, Chandra K. Singh, B Jack Longley, Nihal Ahmad. A pro-proliferative function of centriole duplication regulator, polo-like kinase-4 in human melanoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr LB-102.

Abstract LB-228: Polo-like kinase 4: A potential new target for the management of prostate cancer

Prostate cancer (PCa) is the most prevalent non-cutaneous cancer of males. According to an estimate from the American Cancer Society, it is expected that approximately 180,890 new cases of PCa will be diagnosed and 26,120 PCa-related deaths will occur in the United States in 2016. Therefore, identification of additional molecular target(s) could be useful in designing novel mechanism-based approaches for the prevention and/or therapy of PCa. PLK4 belongs to the polo-like kinase family of serine/threonine protein kinases that localizes to centrioles and regulates centriole duplication during the cell cycle. Essentially, PLK4 is a low abundance suicidal kinase that is known to auto-phosphorylate itself to promote its own destruction to limit centriole duplication once per cell cycle phase. Since centrosome aberrations are frequently seen in cancer, the central role of PLK4 in centriole duplication suggests its significance as a potential target for cancer management. However, the role and functional relevance of PLK4 in PCa development and progression has not been investigated. In this study, we determined the expression profile of PLK4 in PCa using immunohistochemical analysis of multiple tissue microarrays (TMAs) containing a variety of cancerous and benign human prostate tissues. The TMAs were immunostained for PLK4 and the images were scanned and analyzed for protein levels using Aperio ScanScope at 40x magnification. We found a significant upregulation of PLK4 in PCa, compared to benign prostatic tissues. Further, we found a significant upregulation of PLK4 protein and mRNA in human PCa cells, as assessed by western blot and qRT-PCR analyses, respectively. To further assess the relevance of PLK4 overexpression in PCa, we determined the effect of a small molecule inhibitor of PLK4, centrinone-B, on androgen-responsive 22Rν1 and androgen-independent DU145 human PCa cells. Centrinone-B treatment (0, 50, 100 and 200 nM; for 24 and 48 h) resulted in a marked decrease in growth and viability of PCa cells, as assessed i) by CytoTox-Glo™ cytotoxicity assay, and ii) microscopic evaluation of cells following staining with Nuclear Fast Red and Crystal Violet dyes. Further, centrinone-B treatment resulted in a G1 phase cell cycle arrest of human PCa cells. Taken together, our study provides first direct evidence of a pro-proliferative function of PLK4 in PCa. However, additional studies are required to ascertain the relevance of our in vitro findings to in vivo situations in relevant animal models.

Citation Format: Chandra K. Singh, Maria Shabbir, Minakshi Nihal, Kenneth A. Iczkowski, Nihal Ahmad. Polo-like kinase 4: A potential new target for the management of prostate cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr LB-228.

Abstract 3667: Potential role of DUSP4 as a tumor suppressor in pancreatic cancer

Pancreatic cancer remains one of the most lethal of all human malignancies, with 48,960 expected new cases and 40,560 deaths predicted in the USA in the year 2015. In order to develop novel strategies for the management of pancreatic cancer, it is of utmost importance to intensify our efforts to dissect the molecular mechanisms involved in the pathophysiology of this fatal neoplasm. Dual-specificity phosphatase-4 (DUSP4), a family member of dual-specificity phosphatases, is capable of dephosphorylating both phosphotyrosine and phosphoserine/phosphothreonine residues and possesses activity against key signaling components of the MAPK pathway that plays an important role in cancer growth. DUSP4 has been shown to be widely expressed in different tissues and implicated in cancer development, differentiation, apoptosis and inflammation. In a recent study from our laboratory that was aimed at defining the molecular targets of the anti-cancer plant-based alkaloid sanguinarine in pancreatic cancer, we identified DUSP4 as a key protein modulated by sanguinarine. Specifically, based on proteomics data and validation by qRT-PCR and immunoblot analysis, we found that sanguinarine significantly increases DUSP4 in BxPC-3 and MIA PaCa-2 pancreatic cancer cells. Indeed, an association of DUSP4 loss with cancer progression has been shown in certain cancers. However, the role of DUSP4 in pancreatic cancer is not known. This study was designed to determine the role and importance of DUSP4 in pancreatic cancer. We determined the expression profile of DUSP4 in pancreatic cancer using immunohistochemical analysis of a tissue microarray containing a variety of pancreatic cancers and normal pancreatic tissues. The DUSP4-immunostaining was microscopically imaged followed by quantification of DUSP4 protein by multispectral Vectra™ system coupled with inForm software. We found a significant downregulation of DUSP4 in human pancreatic cancer tissues, when compared to normal pancreatic tissues. Further, to understand the importance of DUSP4 in pancreatic cancer, we determined the effect of a force overexpression of DUSP4 in MIA PaCa-2 pancreatic cancer cells. We found that DUSP4 overexpression in MIA PaCa-2 cells resulted in a significant i) decrease in cell growth and proliferation, ii) clonogenic survival, and iii) induction of apoptosis. These preliminary findings suggest a potential tumor suppressive function of DUSP4 in pancreatic cancer. Further detailed studies are ongoing in our laboratory to validate the role and functional significance of DUSP4 in pancreatic cancer.

Citation Format: Chandra K. Singh, Jasmine George, Minakshi Nihal, Nihal Ahmad. Potential role of DUSP4 as a tumor suppressor in pancreatic cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3667.

Molecular signatures of sanguinarine in human pancreatic cancer cells: A large scale label-free comparative proteomics approach

Pancreatic cancer remains one of the most lethal of all human malignancies with its incidence nearly equaling its mortality rate. Therefore, it's crucial to identify newer mechanism-based agents and targets to effectively manage pancreatic cancer. Plant-derived agents/drugs have historically been useful in cancer therapeutics. Sanguinarine is a plant alkaloid with anti-proliferative effects against cancers, including pancreatic cancer. This study was designed to determine the mechanism of sanguinarine's effects in pancreatic cancer with a hope to obtain useful information to improve the therapeutic options for the management of this neoplasm. We employed a quantitative proteomics approach to define the mechanism of sanguinarine's effects in human pancreatic cancer cells. Proteins from control and sanguinarine-treated pancreatic cancer cells were digested with trypsin, run by nano-LC/MS/MS, and identified with the help of Swiss-Prot database. Results from replicate injections were processed with the SIEVE software to identify proteins with differential expression. We identified 37 differentially expressed proteins (from a total of 3107), which are known to be involved in variety of cellular processes. Four of these proteins (IL33, CUL5, GPS1 and DUSP4) appear to occupy regulatory nodes in key pathways. Further validation by qRT-PCR and immunoblot analyses demonstrated that the dual specificity phosphatase-4 (DUSP4) was significantly upregulated by sanguinarine in BxPC-3 and MIA PaCa-2 cells. Sanguinarine treatment also caused down-regulation of HIF1α and PCNA, and increased cleavage of PARP and Caspase-7. Taken together, sanguinarine appears to have pleotropic effects, as it modulates multiple key signaling pathways, supporting the potential usefulness of sanguinarine against pancreatic cancer.

Combination chemoprevention with grape antioxidants

Antioxidant ingredients present in grape have been extensively investigated for their cancer chemopreventive effects. However, much of the work has been done on individual ingredients, especially focusing on resveratrol and quercetin. Phytochemically, whole grape represents a combination of numerous phytonutrients. Limited research has been done on the possible synergistic/additive/antagonistic interactions among the grape constituents. Among these phytochemical constituents of grapes, resveratrol, quercetin, kaempferol, catechin, epicatechin, and anthocyanins (cyanidin and malvidin) constitute more than 70% of the grape polyphenols. Therefore, these have been relatively well studied for their chemopreventive effects against a variety of cancers. While a wealth of information is available individually on cancer chemopreventive/anti-proliferative effects of resveratrol and quercetin, limited information is available regarding the other major constituents of grape. Studies have also suggested that multiple grape antioxidants, when used in combination, alone or with other agents/drugs show synergistic or additive anti-proliferative response. Based on strong rationale emanating from published studies, it seems probable that a combination of multiple grape ingredients alone or together with other agents could impart 'additive synergism' against cancer.

Pro-Proliferative Function of Mitochondrial Sirtuin Deacetylase SIRT3 in Human Melanoma

Melanoma, the most aggressive form of skin cancer, is often fatal if not treated early. Therefore, novel target-based strategies are required to combat this neoplasm. The objective of this study was to determine the role and functional significance of the mitochondrial sirtuin 3 (SIRT3) in melanoma. We found that compared with normal primary and immortalized human melanocytes, SIRT3 is significantly overexpressed in multiple human melanoma cells at mRNA and protein levels. Further, employing human tissue microarray, we found that SIRT3 is significantly upregulated in clinical melanoma tissues, compared with melanocytic nevi tissues. Furthermore, a short hairpin RNA-mediated knockdown of SIRT3 in human melanoma cells resulted in (i) a decrease in cellular proliferation, colony formation, and cellular migration; (ii) induction of senescence as shown by an increase in senescence-associated beta-galactosidase activity and formation of senescence-associated heterochromatin foci as well as an increase in mRNA and protein levels of p16(INK4a) and p21(Waf1); (iii) G1-phase arrest of the cell cycle; and (iv) decreases in mRNA and protein levels of cyclins (D1, E1) and cyclin-dependent kinases (2, 4, and 6). Conversely, forced exogenous overexpression of SIRT3 promoted an increase in proliferative potential of Hs294T melanoma cells and normal immortalized Mel-ST melanocytes. Finally, we found that SIRT3 knockdown significantly inhibited tumorigenesis in a xenograft model in vivo. To our knowledge, this is the first study supporting the pro-proliferative function of SIRT3 in melanoma.

Sirtuin deacetylases: a new target for melanoma management

Melanoma continues to cause more deaths than any other skin cancer, necessitating the development of new avenues of treatment. One promising new opportunity comes in the form of mechanism-based therapeutic targets. We recently reported the overexpression and delocalization of the class III histone deacetylase SIRT1 in melanoma, and demonstrated that its small molecule inhibition via Tenovin-1 decreased cell growth and viability of melanoma cells, possibly by a p53 mediated induction of p21. Here, we support our data using additional SIRT inhibitors, viz. Sirtinol and Ex-527, which suggests possible benefits of concomitantly inhibiting more than one Sirtuin for an effective cancer management strategy. This "Extra View" paper also includes a discussion of our results in the context of similar recent and concurrent studies. Furthermore, we expand upon our findings in an analysis of new research that may link the cellular localization and growth effects of SIRT1 with the PI3K signaling pathway.

Abstract 4643: Effect of resveratrol-zinc combination on prostate tumor growth in transgenic adenocarcinoma of mouse prostate (TRAMP) model

Prostate cancer (PCa) is a major cancer of males globally and is associated with significant mortality and morbidity across the globe. The trace element zinc (Zn) plays a critical role in a variety of prostatic functions and normal prostate accumulates Zn at up to ten-fold higher concentration than other soft tissues in the body. However, the cancerous prostate lose the ability to accumulate Zn and lower levels of prostatic Zn has been associated with development and progression of PCa. Studies have suggested that a dysregulation in the transport machinery of Zn, possibly mediated via ZIP and ZnT families of Zn transporters, may be associated with this neoplastic transformation of prostate. Thus, re-tuning of Zn transport machinery via pharmacological means could be useful in PCa management. We have previously demonstrated that the grape antioxidant resveratrol (RSV) enhances the anti-proliferative response of Zn by increasing Zn-transporter protein ZIP1 in prostate cancer cells in vitro (Cancer Res 2012; 72(8 Suppl): Abstract nr 3729. doi: 1538-7445.AM2012-3729). Here, we extended our study to determine the in vivo relevance of our in vitro findings. We assessed the effect of RSV (600 mg/kg in diet) in combination with Zn (15 and 30 ppm ZnSO4.7H2O in drinking water) against prostate cancer progression in TRAMP mice, employing two experimental protocols, which represent prevention and intervention settings, respectively. We found that RSV-Zn combination, when given prior to tumor initiation (4 weeks of age), showed superior anti-tumor efficacy than either of the agents alone. However, we did not find a significant anti-tumor response of RSV and/or Zn in the intervention protocol. We also determined the effect of RSV and/or treatments on markers of proliferation and apoptosis in tumor tissues obtained from TRAMP mice. Interestingly, we found that lower dose of Zn (15 ppm) was most consistent in imparting anti-proliferative response; resulting in a significant i) decrease in tumor weight/volume, ii) decrease in proliferative marker PCNA, iii) increase of pro-apoptotic Bax, and iv) decrease of the pro-survival Bcl2. In addition, the observed response of RSV-Zn combination was associated with an increase in ZIP4 protein. Further experiments are ongoing to dissect the mechanism of the PCa chemoprevention effects of RSV-Zn combination. Outcome of this study may provide a foundation for the use of RSV-Zn combination for PCa management.

Citation Format: Chandra K. Singh, Minakshi Nihal, Jasmine George, Imtiaz A. Siddiqui, Hasan Mukhtar, Nihal Ahmad. Effect of resveratrol-zinc combination on prostate tumor growth in transgenic adenocarcinoma of mouse prostate (TRAMP) model. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4643. doi:10.1158/1538-7445.AM2015-4643

Abstract 2801: Resveratrol-Quercetin combination significantly inhibits prostate cancer in TRAMP mice

Worldwide, prostate cancer (PCa) is the second most frequently diagnosed cancer and the sixth leading cause of cancer death in males. The existing treatments as well as surgical approaches have not been fully effective in PCa management. Therefore, new mechanism-based approaches are needed for the prevention as well as therapy of PCa. Resveratrol (trans-3,5,4′-trihydroxystilbene), an antioxidant found in red grapes, has been shown to afford chemopreventive as well as therapeutic effects against several cancers. We have advocated the idea that resveratrol may be better utilized for cancer management, when given in combination with other agents. A number of in vitro and in vivo studies have suggested potential usefulness of resveratrol in PCa management. However, an important issue associated with the potential clinical/human use of resveratrol is its low in vivo bioavailability, due to its rapid metabolism (via glucuronidation, sulfation and hydroxylation). Quercetin, also a flavonoid, has been shown to inhibit in vivo sulfation of resveratrol. Interestingly, resveratrol and quercetin, both are found in red grapes and several other plants, indicating their natural association. Like resveratrol, quercetin has also been shown to inhibit PCa in animal models. In this study, we tested the hypothesis that resveratrol-quercetin combination may have better efficacy against PCa as quercetin, in addition to its own effect, can enhance the bioavailability of resveratrol via inhibiting its sulfation, thereby imparting superior anti-proliferative efficacy. We found that resveratrol-quercetin combination resulted in a superior anti-proliferative response in multiple human PCa cell lines (22Rν1, DU145 and PC3), as assessed by MTT (3-(4, 5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide) assay for cellular metabolic activity, and trypan blue exclusion analysis for cell growth and viability. Further, clonogenic survival assay, where equal number of treated cells were allowed to grow for two weeks, showed that the combination was superior to resveratrol or quercetin alone. To ascertain the in vivo relevance of in vitro data, we determined the effects of resveratrol-quercetin combination on PCa development and progression in TRAMP model, which closely mimics hallmark features of human PCa. We conducted prevention and intervention trials employing four experimental groups, 1) control (AIN76A diet), 2) resveratrol (600 mg/kg in diet), 3) quercetin (60 mg/kg in diet), and 4) resveratrol (600 mg/kg in diet) + quercetin (60 mg/kg in diet). Our data demonstrated that resveratrol-quercetin combination was markedly superior to either of the individual agents, in intervention setting when treatment was started after the onset of PCa in TRAMP mice. Further studies are ongoing in our laboratory to determine the mechanism(s) associated with the observed effect of resveratrol-quercetin combination.

Citation Format: Chandra K. Singh, Nihal Ahmad. Resveratrol-Quercetin combination significantly inhibits prostate cancer in TRAMP mice. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2801. doi:10.1158/1538-7445.AM2015-2801

Abstract 1127: Small molecule SIRT3 inhibitor 4′-bromo-resveratrol inhibits proliferation, promotes apoptosis and causes metabolic reprograming of human melanoma cells

Sirtuin-3 (SIRT3) is an important mitochondria NAD+-dependent deacetylase that is known to target mitochondrial proteins for deacetylation and regulates a variety of cellular functions. We have previously shown that SIRT3 was overexpressed in human melanoma cells and tissues and its genetic knockdown resulted in a significant antiproliferative response in human melanoma cells (In: AACR Annual Meeting: Proceedings; 2014 April 5-April 9, San Diego; CA, Abstract # 3516). Our data suggested that small molecule inhibitors of SIRT3 may be developed for the management of melanoma. In this study, we determined the anti-proliferative efficacy of a newly identified small molecule SIRT3 inhibitor, 4′-bromo-resveratrol, in human melanoma cell lines (G361, SK-MEL-28 and SK-MEL-2). Treatment of melanoma cells with 4-bromoresveratrol (0, 12.5, 25, 50, 100, and 200 × 10-3 mM; for 24, 48 and 72 hrs) resulted in a significant decrease in cell proliferation in a dose- and time- dependent manner. In addition, 4′-bromo-resveratrol treatment also resulted in a marked decrease in the growth, viability, clonogenic survival and migration of melanoma cells. Further, the anti-proliferative effects of 4′-bromo-resveratrol were accompanied by a marked downregulation of proliferating cell nuclear antigen (PCNA) protein as well as SIRT3 mRNA and protein. Furthermore, 4′-bromo-resveratrol treatment to melanoma cells resulted in 1) significant induction of apoptosis in melanoma cells, as evident from increase in PARP cleavage, decrease in pro-caspase-3, pro-caspase-8; and 2) G0/G1 phase cell cycle arrest. We also observed a marked increase in WAF-1/p21 protein levels and decreases in cyclin D1 and cdk2 protein levels as a result of 4′-bromo-resveratrol treatment in melanoma cells. Finally, we also found that 4′-bromo-resveratrol caused a metabolic reprograming in human melanoma cells as shown by decreases in the levels of lactate production, glucose uptake, NAD+/NADH ratio, which were accompanied by downregulation in protein levels of lactate dehydrogenase A (LDHA) and glucose transporter 1 (Glut1) in melanoma cells. Collectively, our data suggest that the small molecule SIRT3 inhibitors, including 4′-bromo-resveratrol, may be developed for melanoma management. However, detailed mechanistic studies as well as in vivo validation studies in appropriate animal model(s) are needed to ascertain the clinical potential of 4′-bromo-resveratrol and/or other SIRT3 inhibitors.

Citation Format: Jasmine George, Minakshi Nihal, Chandra K. Singh, Nihal Ahmad. Small molecule SIRT3 inhibitor 4′-bromo-resveratrol inhibits proliferation, promotes apoptosis and causes metabolic reprograming of human melanoma cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1127. doi:10.1158/1538-7445.AM2015-1127

Resveratrol, in its natural combination in whole grape, for health promotion and disease management

The grape antioxidant resveratrol has been a topic of intense research for the past three decades. Resveratrol and other grape ingredients, as well as whole-grape products, have shown considerable promise in health promotion and disease management. Phytochemically, whole grape represents a natural combination of resveratrol and other phytonutrients, as it contains several catechins, anthocyanins, polyphenols, and flavonols. Thus, whole grape products or specific combinations of grape constituents provide us with the possibility of synergistic interactions leading to improved efficacy. Recent research has suggested that whole-grape products may help in maintaining heart health and protect against aging, aging-associated diseases, neurodegeneration, and some cancers. On the basis of available recent literature, the grape fruit or whole-grape products seem to be safer choices for better health and disease prevention. However, for advanced disease conditions, individual grape ingredients (such as resveratrol) or combinations of multiple ingredients, together with existing therapies, appear to be better approaches. Further clinical studies are needed to understand the benefits of grapes and their products in the prevention and management of specific diseases.

Methaneseleninic acid and γ-Tocopherol combination inhibits prostate tumor growth in Vivo in a xenograft mouse model

Studies have shown that vitamin E and selenium possess antiproliferative effects against prostate cancer (PCa). However, results from the Selenium and Vitamin E Cancer Prevention Trial (SELECT) suggest that vitamin E (α-tocopheryl acetate; 400 mg) and/or selenium (L-selenomethionine; 200 μg) were ineffective against PCa in humans. It is arguable that the selected dose/formulation of vitamin E/selenium were not optimal in SELECT. Thus, additional studies are needed to define the appropriate formulations/dose regimens of these agents. Here, we investigated the effect of methaneseleninic acid (MSA; 41 μg/kg) and/or γ-tocopherol (γT; 20.8 mg/kg or 41.7 mg/kg) in Nu/J mice implanted with 22Rν1 tumors. MSA (41 μg/kg) and γT (20.8 mg/kg) combination was most consistent in imparting anti-proliferative response; resulting in a significant decrease in i) tumor volume/weight, ii) serum PSA, and iii) Ki-67 immunostaining. Further, we observed i) an upregulation of pro-apoptosis Bax and a down-regulation of the pro-survival Bcl2, and ii) an increase in pro-apoptosis Bad. Furthermore, the combination resulted in a modulation of apolipoprotein E, selenoprotein P and Nrf2 in a fashion that favors antiproliferative responses. Overall, our study suggested that a combination of MSA and γT, at lower dose regimen, could be useful in PCa management.

Comparison of immunochromatographic diagnostic test with Hheminested Reverse transcriptase polymerase chain reaction for detection of rabies virus from brain samples of various species

AIM

Detection of rabies is a cause of serious concern in developing countries, where dearth of highly equipped laboratories and trained personnel to handle sophisticated investigations is felt. The availability of a diagnostic kit, which can be used in the field, is essential for diagnosis and control programs as well as for epidemiological surveillance of the prevalence of the disease. This study was planned to evaluate anigen rabies Ag test kit for its efficacy to be used for rapid diagnosis of rabies under field conditions. The test results were compared with hemi-nested reverse transcriptase polymerase chain reaction and with a gold standard fluorescent antibody test.

MATERIALS AND METHODS

A total of 34 brain samples from different rabies suspected animals including dogs, buffaloes, cow, horse, and cat were examined in this study.

RESULTS

Sensitivity of the kit was found to be 91.66%, specificity 100%, and accuracy was 94.11%.

CONCLUSION

The study implies that the immunochromatographic diagnostic test kit may be employed for diagnosis of rabies in field conditions.

Novel downstream molecular targets of SIRT1 in melanoma: a quantitative proteomics approach

Melanoma is one of the most lethal forms of skin cancer and its incidence is continuing to rise in the United States. Therefore, novel mechanism and target-based strategies are needed for the management of this disease. SIRT1, a NAD(+)-dependent class III histone deacetylase, has been implicated in a variety of physiological processes and pathological conditions. We recently demonstrated that SIRT1 is upregulated in melanoma and its inhibition by a small-molecule, tenovin-1, inhibits cell proliferation and clonogenic survival of melanoma cells, possibly via activating p53. Here, we employed a gel free quantitative proteomics approach to identify the downstream effectors and targets of SIRT1 in melanoma. The human malignant melanoma, G361 cells were treated with tenovin-1 followed by protein extraction, in liquid trypsin digestion, and peptide analyses using nanoLC-MS/MS. A total of 1091 proteins were identified, of which 20 proteins showed significant differential expression with 95% confidence interval. These proteins were subjected to gene ontology and Ingenuity Pathway Analysis (IPA) to obtain the information regarding their biological and molecular functions. Real-Time qRT-PCR validation showed that five of these (PSAP, MYO1B, MOCOS, HIS1H4A and BUB3) were differentially expressed at mRNA levels. Based on their important role in cell cycle regulation, we selected to focus on BUB family proteins (BUB3, as well as BUB1 and BUBR1) for subsequent validation. The qRT-PCR and immunoblot analyses showed that tenovin-1 inhibition of SIRT1 resulted in a downregulation of BUB3, BUB1 and BUBR1 in multiple melanoma cell lines. Since tenovin-1 is an inhibitor of both SIRT1 and SIRT2, we employed lentivirus mediated silencing of SIRT1 and SIRT2 in G361 cells to determine if the observed effects on BUB family proteins are due to SIRT1- or SIRT2- inhibition. We found that only SIRT1 inhibition resulted in a decrease in BUB3, BUB1 and BUBR1. Our study identified the mitotic checkpoint regulator BUB family proteins as novel downstream targets of SIRT1. However, further validation is needed in appropriate models to confirm our findings and expand on our observations.

Resveratrol and cancer: Challenges for clinical translation

Significant work has been done towards identifying the health-beneficial effects of the grape antioxidant resveratrol in a variety of bioassay- and disease- models, with much research being focused on its possible application to cancer management. Despite the large number of preclinical studies dealing with different aspects of the biological effects of resveratrol, its translation to clinics is far from reality due to a variety of challenges. In this review, we discuss the issues and questions associated with resveratrol becoming an effective in vivo anticancer drug, from basic metabolic issues to the problems faced by incomplete understanding of the mechanism(s) of action in the body. We also explore efforts taken by researchers, both public and private, to contend with some of these issues. By examining the published data and previous clinical trials, we have attempted to identify the problems and issues that hinder the clinical translation of resveratrol for cancer management. This article is part of a Special Issue entitled: Resveratrol: Challenges in translating pre-clinical findings to improved patient outcomes.

Abstract 3516: The mitochondrial sirtuin SIRT3 promotes survival of human melanoma cells in vitro

Melanoma, a potentially lethal form of skin cancer, is the fifth most common type of new cancer diagnosis in American men and the sixth most common type in American women. Alarmingly, the annual incidence of melanoma among whites has increased steadily (>60% over the past 30 years). Despite new developments in therapy, the overall survival of patients with advance-stage melanoma has not significantly improved. Therefore, concerted mechanism-based efforts are needed for prevention, diagnosis and treatment of this deadly neoplasm. A better understanding of molecular mechanisms contributing to melanoma development and progression can be useful in crafting new strategies for melanoma management. We are studying the role of sirtuin family of proteins in melanoma development and progression. Mammalian sirtuins (SIRT 1-7) are nicotinamide adenine dinucleotide (NAD+)-dependent protein deacetylases, which have been shown to regulate metabolism, stress responses, and longevity, in model organisms. The role of sirtuins in cancer is fairly complex with dichotomous functions (tumor promoter versus tumor suppressor) depending on cell contexts. SIRT3 is a mitochondrial deacetylase that has been shown to be important in maintaining cellular metabolism by regulating mitochondrial functions. We have previously shown that SIRT3 was overexpressed in human melanoma cells and tissues and its inhibition resulted in an antiproliferative response in human melanoma cells (In: AACR Annual Meeting: Proceedings; 2013 April 6-April 10, Washington, DC; Abstract # 13-LB-9391). In this study, we found that short hairpin RNA (shRNA)-mediated knockdown of SIRT3 in SK-MEL-28 melanoma cells resulted in 1) G1-phase arrest of cell cycle, 2) induction of senescence as assessed by increase in senescence-associated β-galactosidase (SA-β-gal) activity, 3) senescence associated hetrochromatin formation (SAHF), 4) decrease in cell migration, and 5) increase in protein levels of p53, phospho-p53 (Ser15), p21Waf1, pRb and p16INK4a. Further, a stable exogenous overexpression of SIRT3 resulted in an increase in cell growth and clonogenic survival in Hs 294T melanoma cells. Based on our data we suggest that SIRT3 could be a contributing factor in melanoma survival. However, further extensive in-vitro and in- vivo studies are needed to ascertain the functional significance of SIRT3 in melanoma development and progression.

Citation Format: Jasmine George, Minakshi Nihal, Chandra K. Singh, Weixiong Zhong, Nihal Ahmad. The mitochondrial sirtuin SIRT3 promotes survival of human melanoma cells in vitro. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3516. doi:10.1158/1538-7445.AM2014-3516

Abstract 235: Combination of the probiotic Lactobacillus rhamnosus GG with grape antioxidant resveratrol for the management of colorectal cancer

Colorectal cancer (CRC), also known as colon/bowel cancer, is the third most commonly diagnosed cancer in the world. In the United States, 142,820 new cases of CRC and 50,830 CRC-related deaths are predicted for the year 2013. CRC has been widely associated with lifestyle and aging. Treatment for CRC varies greatly based on disease severity and is curable with surgery, only if detected very early. It is being increasingly appreciated that nutritional and lifestyle modification might prevent or delay certain cancers, including CRC. Imbalance in gut microbiome, due to lifestyle and dietary habits, can lead to a variety of intestinal disorders including excessive immune response and inflammation that might ultimately lead to CRC. The probiotics, which are live microorganisms, have been shown to promote healthy microbiome balance in gut to support healthy colon. For an optimal functioning, the probiotics need to remain viable. This might be achieved via prebiotics and prebiotics-like substances that confer beneficial effects by promoting the microbiota. Therefore, novel means to balance the gut microbiota by prebiotic-probiotic combination could be useful in the management of inflammation related CRC. The grape antioxidant resveratrol (RSV) has been shown to support the health of beneficial gut bacteria, thus functioning essentially as a prebiotic. The goal of this study was to determine if a combination of the resveratrol and the probiotic Lactobacillus rhamnosus GG (LGG) imparts anti-proliferative response in human CRC cell lines, DLD 1 and RKO. For our experiments, DLD1 and RKO cells (∼50% confluent) were treated with RSV and cell free supernatants of LGG. RSV was used at a single concentration (10 µM) whereas LGG cell-free supernatants were used at two concentrations: LGG1 (2.125 x 105 CFU/mL) and LGG2 (4.35 x 105 CFU/mL). We found that a combination of LGG and RSV resulted in a significant decrease in the growth and viability of DLD 1 and RKO cells, as assessed by MTT- and Trypan Blue exclusion- assays. Further, LGG-RSV combination resulted in a marked decrease in the clonogenic survival of CRC cells, as assessed by colony formation abilities of of DLD 1 and RKO cells. Furthermore, LGG-RSV combination resulted in an induction of apoptosis in CRC cells, as determined by cleavage of protein poly (ADP-ribose) polymerase (PARP). Overall, our study provides a proof of principle for the potential use of RSV-LGG combination in CRC management. However, further in vivo studies in appropriate animal model(s) are needed to determine the efficacy of RSV-LGG combination in prevention of CRC.

Citation Format: Chandra K. Singh, Jasmine George, Megan Duster, Nasia Safdar, Nihal Ahmad. Combination of the probiotic Lactobacillus rhamnosus GG with grape antioxidant resveratrol for the management of colorectal cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 235. doi:10.1158/1538-7445.AM2014-235

Abstract 4533: Mechanism of anti-proliferative effects of sanguinarine in pancreatic cancer cells: A label-free quantitative proteomics approach

Pancreatic cancer is one of the most lethal cancers, with a meager (∼3%) 5-year survival rate. The incidence of pancreatic cancer nearly equals its death rate as this neoplasm is associated with poor responsiveness to conventional chemotherapies. Therefore, it's crucial to identify newer mechanism-based agents and targets to effectively manage pancreatic cancer. Previous studies from our laboratory have demonstrated that the plant alkaloid sanguinarine (13-methyl[1,3]benzodioxolo [5,6-c]-1,3-dioxolo [4,5-i] phenanthridinium possesses strong antiproliferative effects against human pancreatic carcinoma cells (Cancer Letters 249; 198-208, 2007). In this study, employing a large-scale Nano-ESI ultra high resolution label-free quantitative proteomics, we attempted to determine the mechanism of sanguinarine's biological response in human pancreatic cancer cells. Based on pilot experiments, we selected BxPC-3 cells and a 1 microM sanguinarine treatment for 24 hours for our proteomics study. Proteins from control and sanguinarine-treated BxPC-3 cells were digested with trypsin followed by nano-liquid chromatography-tandem mass spectrometry (LC/MS/MS). Following LC/MS/MS acquisition, the data were searched against the Swiss-Prot human proteome database using Sequest HT search engine under the Proteome Discoverer 1.4 software (Thermo Fisher Scientific). Following protein identification, the LC/MS/MS data was aligned using Chromalign and quantitation of peptides was performed on the processed data using Sieve 2.1 (Thermo Fisher Scientific). A cumulative data of a total of 6 replicates (2 biological and 3 technical) were run and analyzed. Upon comparison with untreated control, 37 proteins (from a total of 3108) showed +1.8 fold significant differential expressions (p value <0.05). These proteins can be categorized under distinct biological functions: 1) cellular assembly and organization, 2) cellular function and maintenance, 3) inflammatory response, and 4) cell death and survival. On further data analysis and validation using real-time qPCR and Western blot analyses, we identified the dual specificity phosphatase-4 (DUSP4), as a novel target of sanguinarine in pancreatic cancer cells. In order to determine the clinical relevance of DUSP4 in pancreatic cancer cells, we determined the expression profile of DUSP4 in a tissue microarray (TMA) containing a wide range of pancreatic cancer tissue (different stages) and normal pancreas tissue from autopsy. We found that that DUSP4 is markedly downregulated in cancerous pancreatic tissues. Our data identified, for the first time, DUPS4 as a potential tumor suppressor in pancreatic cancer and a novel target of sanguinarine. However, further studies are needed to validate our findings in detailed in vitro and in vivo studies.

Citation Format: Chandra K. Singh, Satwinderjeet Kaur, Jasmine George, Molly C. Pellitteri-Hahn, Cameron O. Scarlett, Nihal Ahmad. Mechanism of anti-proliferative effects of sanguinarine in pancreatic cancer cells: A label-free quantitative proteomics approach. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4533. doi:10.1158/1538-7445.AM2014-4533

Resveratrol-zinc combination for prostate cancer management

Zinc, an essential trace element, plays a critical role in cell signaling, and defect(s) in zinc homeostasis may contribute to adverse physiological and pathological conditions, including cancer. Zinc is present in healthy prostate at a very high concentration, where it is required for important prostatic functions. However, zinc levels are significantly diminished in cancerous tissue, and intracellular zinc level is inversely correlated with prostate cancer progression. During neoplastic transformation, zinc-accumulating, citrate-producing normal prostate cells are metabolically transformed to citrate oxidizing cells that lose the ability to accumulate zinc. Interestingly, zinc has been shown to function as chemopreventive agent against prostate cancer, albeit at high doses, which may lead to many adverse effects. Therefore, novel means to enhance bioaccumulation of sufficient zinc in prostate cells via increasing zinc transport could be useful against prostate cancer. On the basis of available evidence, we present a possibility that the grape antioxidant resveratrol, when given with zinc, may lead to retuning the zinc homeostasis in prostate, thereby abolishing or reversing malignancy. If experimentally verified in in vivo model(s) of prostate cancer, such as transgenic mouse models, this may lead to novel means toward management of prostate cancer and other conditions with compromised zinc homeostasis.

Resveratrol-based combinatorial strategies for cancer management

In recent years combination chemoprevention has been increasingly appreciated and investigated as a viable and effective strategy for cancer management. A plethora of evidence suggests that a combination of agents may afford synergistic (or additive) advantage for cancer management by multiple means, such as by (1) enhancing the bio-availability of chemopreventive agents, (2) modifying different molecular targets, and (3) lowering the effective dose of agent/drug to be used for cancer management. Resveratrol has been shown to afford chemopreventive and therapeutic effects against certain cancers. Recent studies are suggesting that resveratrol may be very useful when given in combination with other agents. The two major advantages of using resveratrol in combination with other agents are synergistically or additively enhancing the efficacy against cancer and limiting the toxicity and side effects of existing therapies. However, concerted and multidisciplinary efforts are needed to identify the most optimal combinatorial strategies.

Diabetic complications in pregnancy: is resveratrol a solution?

Diabetes is a metabolic disorder that, during pregnancy, may affect fetal development. Fetal outcome depends on the type of diabetes present, the concentration of blood glucose and the extent of fetal exposure to elevated or frequently fluctuating glucose concentrations. The result of some diabetic pregnancies will be embryonic developmental abnormalities, a condition referred to as diabetic embryopathy. Tight glycemic control in type 1 diabetes during pregnancy using insulin therapy together with folic acid supplementation are partially able to prevent diabetic embryopathy; however, the protection is not complete and additional interventions are needed. Resveratrol, a polyphenol found largely in the skins of red grapes, is known to have antidiabetic action and is in clinical trials for the treatment of diabetes, insulin resistance, obesity and metabolic syndrome. Studies of resveratrol in a rodent model of diabetic embryopathy reveal that it significantly improves the embryonic outcome in terms of diminishing developmental abnormalities. Improvements in maternal and embryonic outcomes observed in rodent models may arise from resveratrol's antioxidative potential, antidiabetic action and antidyslipidemic nature. Whether resveratrol will have similar actions in human diabetic pregnancy is unknown. Here, we review the potential therapeutic use of resveratrol in diabetes and diabetic pregnancy.

Diabetic complications in pregnancy: is resveratrol a solution?

Diabetes is a metabolic disorder that, during pregnancy, may affect fetal development. Fetal outcome depends on the type of diabetes present, the concentration of blood glucose and the extent of fetal exposure to elevated or frequently fluctuating glucose concentrations. The result of some diabetic pregnancies will be embryonic developmental abnormalities, a condition referred to as diabetic embryopathy. Tight glycemic control in type 1 diabetes during pregnancy using insulin therapy together with folic acid supplementation are partially able to prevent diabetic embryopathy; however, the protection is not complete and additional interventions are needed. Resveratrol, a polyphenol found largely in the skins of red grapes, is known to have antidiabetic action and is in clinical trials for the treatment of diabetes, insulin resistance, obesity and metabolic syndrome. Studies of resveratrol in a rodent model of diabetic embryopathy reveal that it significantly improves the embryonic outcome in terms of diminishing developmental abnormalities. Improvements in maternal and embryonic outcomes observed in rodent models may arise from resveratrol's antioxidative potential, antidiabetic action and antidyslipidemic nature. Whether resveratrol will have similar actions in human diabetic pregnancy is unknown. Here, we review the potential therapeutic use of resveratrol in diabetes and diabetic pregnancy.

Abstract 2509: Mechanism of anti-proliferative effects of SIRT1 inhibition in melanoma cells: a proteomics approach

An analysis of the SEER (Surveillance, Epidemiology, and End Results) program data has suggested that the age-adjusted annual incidence of melanoma in both young men and women has increased over the past 20 years. The current therapeutic options have shown little success in melanoma management. Therefore, novel mechanism and target-based strategies are needed for the management of this disease. The mammalian SIRT1 or sirtuin (silent mating type information regulation 2 homolog) 1 is a NAD(+)-dependent class III histone deacetylase (HDAC) that has been shown to play important roles in a variety of biological processes and diseases including cancer. Previous studies from our laboratory have demonstrated that 1) SIRT1 is overexpressed in human melanoma cells and tissues; 2) SIRT1 inhibition by Tenovin-1 resulted in decreased growth, viability, and clonogenic survival of melanoma cells; 3) Tenovin-1 treatment resulted in decreased level of SIRT1 protein and increased level of the tumor suppressor p53 (In: AACR Annual Meeting: Proceedings; 2012 March 31-April 4, Chicago, IL; Abstract # 4722). In this study we employed a proteomics approach using gel free Liquid Chromatography-Mass Spectrometry (LC-MS) to identify the downstream molecular targets of SIRT1 in melanoma. The human melanoma G361 cells were treated with Tenovin-1 (25 μM; 48 h) followed by protein extraction. Extracted proteins were precipitated (using 10% TCA and 0.05% DTT), pelleted and washed with acetone and air dried. Samples were re-suspended, labelled, trypsin digested and subjected to LC-MS/MS on a linear trap quadrupole (LTQ) Orbitrap XL. The resultant peptide sequence data were matched against the uniprot_human_FR_CP_090710 database using Mascot (Matrix Sciences, London, UK). Scaffold (version Scaffold_3.6.1, Proteome Software Inc., Portland, OR) was used to validate MS/MS based peptide and protein identifications. Protein identifications were accepted if they could be established at greater than 95% probability and contained at least two identified peptides. The differentially expressed protein data were collected from three different biological replicates. We found 14 proteins (from a total of 1092) which showed +2 fold differential expressions with statistical significance (T-test, p value <0.05). Among these proteins, three proteins were found to be newly expressed whereas one was found to completely disappear following SIRT1 inhibition, under the experimental conditions employed. The differentially expressed proteins identified in our study are associated with RNA processing-, mitochondrial checkpoint- and apoptosis- pathways. Currently, we are in process of validating and ascertaining the functional relevance of these downstream targets. Our provides an improved understanding of SIRT1 downstream targets, which may lead to better strategies for melanoma management.

Citation Format: Chandra K. Singh, Jasmine George, Raj Kumar, Nihal Ahmad. Mechanism of anti-proliferative effects of SIRT1 inhibition in melanoma cells: a proteomics approach. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2509. doi:10.1158/1538-7445.AM2013-2509

Abstract 3693: Methaneseleninic acid and γ-tocopherol combination inhibits prostate tumor growth in a xenograft model

Prostate Cancer (PCa) is the second leading cause of cancer-related deaths in American males. Several in vitro and in vivo studies have suggested that vitamin E as well as selenium possesses potential in the management of PCa. However, results from the large-scale Selenium and Vitamin E Cancer Prevention Trial (SELECT) found that vitamin E (α-tocopheryl acetate; 400 mg) and/or selenium (L-selenomethionine; 200 μg) were ineffective in preventing PCa. Based on these seemingly contradictory outcomes, we believe that the dose and formulation of both these agents were sub-optimal in the SELECT trial, and may be critical in providing appropriate biological response in PCa. Thus, additional studies are needed to define the most appropriate formulations of vitamin E and selenium as well as the optimal dosages of these two agents. Following a careful analysis of literature, we evaluated the effect of methylseleninic acid (MSA in sterile water; oral gavage) and/or γ-tocopherol (γT in tocopherol-stripped corn oil; oral gavage), at a dose much lower than used in SELECT, against prostate tumors in an immunecompromised mouse model. Sixty Nu/J mice were implanted with 22Rν1 cells, tumors were allowed to grow to an average volume of 36 mm3, followed by treatment in 6 groups (10 animals each): 1) Control (vehicle alone); 2) MSA (41 μg/kg); 3) γT (20.8 mg/kg); 4) γT (41.7 mg/kg); 5) MSA (41 μg/kg) + γT (20.8 mg/kg); and 6) MSA (41 μg/kg) + γT (41.7 mg/kg). The mice were treated for 2 weeks (5 days per week) and followed for tumor growth. At the end of experiment, the mice were sacrificed and further studies were done. Our data demonstrated that the combination of γT (20.8 mg/kg) and MSA (41 μg/kg) resulted in a significant decrease in i) serum prostate specific antigen levels, ii) tumor volume and tumor wet weight, and iii) Ki-67 proliferation index. We found that this combination also resulted in i) an up-regulation of pro-apoptotic Bax coupled with a down-regulation of the pro-survival protein Bcl2, thereby resulting in an increased Bax/Bcl2 ratio, and ii) an increase in pro-apoptotic protein Bad. Further, γT and MSA combination modulated levels of apolipoprotein E, selenoprotein P and Nrf2 in a fashion that favors anti-proliferative responses in PCa. Interestingly, we found that the combination using a lower dose of γT was much more effective than the higher dose, in most of the parameters evaluated. In the most effective treatment group, the approximate daily human equivalent dose for γT was 72 mg/day (corresponding to 20.8 mg/kg in mouse) and for MSA is 142 μg/day (corresponding to 41 μg/kg in mouse), which is significantly lower than the doses used in SELECT. Overall, our study suggests that γT and MSA, at the lower dose regimen, could be useful in PCa management. However, further studies with additional formulations and doses in more relevant animal model(s) are needed to confirm our findings.

Citation Format: Chandra K. Singh, Mary A. Ndiaye, Imtiaz A. Siddiqui, Minakshi Nihal, Thomas Havighurst, Weixiong Zhong, Hasan Mukhtar, Nihal Ahmad. Methaneseleninic acid and γ-tocopherol combination inhibits prostate tumor growth in a xenograft model . [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3693. doi:10.1158/1538-7445.AM2013-3693

Abstract LB-209: SIRT3, a mitochondrial sirtuin deacetylase, promotes survival of human melanoma cells

Melanoma is one of the most aggressive skin cancers and is often lethal, if not diagnosed early. The existing therapeutic approaches as well as preventive strategies have not been able to effectively manage melanoma. A better understanding of mechanisms of melanoma development and progression may lead to additional means for the management of this deadly neoplasm. Sirtuins are NAD+-dependent protein deacetylases and mono-[ADP-ribosyl]transferases, which have been shown to regulate metabolism, stress responses, and longevity, in model organisms. Mammalian sirtuins, also referred to as class III histone deacetylases, have seven members (SIRT1-7) that differ widely in their localization, activity, and functions. The role of sirtuins in cancer is extremely complex and they have been shown to exhibit dichotomous functions (tumor promoter versus tumor suppressor) depending on cell contexts. SIRT3 is a mitochondrial deacetylase that regulates the activity of enzymes to coordinate global shifts in cellular metabolism. While studies have suggested that the SIRT3 acts as a tumor suppressor in some cancers (such as breast cancer), the tumor promoter function of SIRT3 has also been reported in other cancers (such as oral squamous cell carcinoma). The objective of this study was to determine the role of the SIRT3 in melanoma. Employing a panel of human melanoma cell lines (SK-MEL-28, WM35 and G361) and normal human epidermal melanocytes (NHEMs), we determined the endogenous levels of SIRT3. We found that compared to NHEMs, SIRT3 is significantly upregulated in human melanoma cells, at mRNA as well as protein levels, as shown by quantitative Real-Time PCR and Western blot analysis, respectively. Further, employing a tissue microarray (TMA) analysis, we determined the expression profile of SIRT3 protein in clinical melanoma and normal skin tissues. We found that SIRT3 is overexpressed in human melanoma, when compared to normal skin. Further, we determined the effect of a short hairpin RNA (shRNA)-mediated RNA interference on melanoma cells. Our data demonstrated that shRNA knockdown of SIRT3 resulted in a significant decrease in the growth, viability and clonogenic survival of human melanoma cells. Taken together, our data suggested that i) SIRT3 overexpression could be a contributing factor in melanoma survival, and ii) SIRT3 could serve as a potential target towards developing novel strategies for the management of melanoma. However, further in-depth studies are needed to determine the functional significance of SIRT3 overexpression in melanoma development and progression.

Citation Format: Jasmine George, Minakshi Nihal, Chandra K. Singh, Nihal Ahmad. SIRT3, a mitochondrial sirtuin deacetylase, promotes survival of human melanoma cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-209. doi:10.1158/1538-7445.AM2013-LB-209

Resveratrol prevents impairment in activation of retinoic acid receptors and MAP kinases in the embryos of a rodent model of diabetic embryopathy

Diabetes induces impairments in gene expression during embryonic development that leads to premature and improper tissue specialization. Retinoic acid receptors (RARs and retinoid X receptor [RXRs]) and mitogen-activated protein kinases (MAPKs) play crucial roles during embryonic development, and their suppression or activation has been shown as a determinant of the fate of embryonic organogenesis. We studied the activation of RARs and MAPKs in embryonic day 12 (E12) in embryos of rats under normal, diabetic, and diabetic treated with resveratrol ([RSV]; 100 mg/kg body weight) conditions. We found downregulation of RARs and RXRs expressions as well as their DNA-binding activities in the embryos exhibiting developmental delays due to diabetes. Furthermore, the phosphorylation of extracellular signal-regulated kinase (ERK) 1/2 was decreased and phosphorylation of c-Jun N-terminal kinase (JNK) 1/2 and p38 was increased. Interestingly, embryos of diabetic rats treated with RSV showed normalized patterns of RARs, RXRs, neuronal markers, and ERK, JNK and p38 phosphorylation.

Abstract 3729: Resveratrol enhances the anti-proliferative response of zinc by increasing zinc-transporter protein ZIP1 in prostate cancer cells: A novel combinatorial approach for prostate cancer management

Prostate Cancer (PCa) is one of the most prevalent cancers in males across the globe. In the United States alone, 240,890 new PCa cases and 33,720 related deaths are predicted for the year 2011. Studies suggest that the essential trace element zinc is extremely important in prostate cell functions and survival. Prostate tissue can accumulate zinc at up to ten-fold higher concentration than other organs. However, the cancerous prostatic cells lose the ability to accumulate zinc and lower levels of prostatic zinc have been associated with PCa development and progression. Based on several studies, it has been suggested that lower expression of zinc transporter protein ZIP1 is associated with this neoplastic transformation and restoration of adequate zinc levels in premalignant/malignant prostate cells can abort prostate malignancy. In addition, zinc has been shown to function as an anti-proliferative agent against PCa. However, because of low ZIP1 in cancerous cells, active transport of zinc into the cells is compromised. Thus, zinc supplementation is not effective since very high concentrations of zinc are needed to achieve enough zinc inside cancerous cells. Therefore new means to enhance the bioaccumulation of sufficient zinc in the prostate tissue could be useful towards PCa management. In this study, we tested the hypothesis that grape antioxidant resveratrol will enhance zinc bioaccumulation via increasing ZIP1 in prostate, to impart a superior anti-proliferative response against PCa cells. Our data demonstrated that ZIP1 protein was markedly downregulated in human PCa tissue as compared to normal prostate tissue. Employing androgen-responsive 22Rα1 and LNCaP as well as androgen-unresponsive DU145 cell lines, we observed that a combination of resveratrol and zinc resulted in a remarkable increase in ZIP1 mRNA and protein expression in PCa cells. Further, a combination of resveratrol and zinc was found to impart a superior anti-proliferative response (inhibition of cell growth/viability and induction of apoptosis) in PCa cells, compared to either of the agent alone. Furthermore, we also found that resveratrol-zinc combination resulted in an increase in the levels of metallothioneins (MT1A, MT1X, MT2A and MT3), which play critical role in regulation of intracellular zinc levels. Taken together, our data indicate that resveratrol enhances the cellular transport of zinc via enhancing ZIP1 transporter protein and a combination of resveratrol and zinc may be a useful approach for PCa management. However, further in vivo studies are needed in appropriate animal model(s) with relevance to human disease to determine the clinical benefits of resveratrol and zinc combination against PCa.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3729. doi:1538-7445.AM2012-3729

Abstract 4722: Targeted inhibition of SIRT1 histone deacetylase by small-molecule inhibitor Tenovin-1 imparts significant anti-proliferative effects in human melanoma cells

Melanoma, one of the most lethal forms of skin cancer, remains resistant to available treatments. Unfortunately, current treatment options are insufficient for preventing the rapid metastasis and death associated with this disease. Thus, additional target-based approaches are needed for the management of this neoplasm. SIRT1, a member of mammalian sirtuin-family and a class III histone deacetylase has been implicated in several cancers. SIRT1 plays an important role in cell survival, as it is involved in DNA repair and inhibits apoptosis and cellular senescene in response to oxidative stress and DNA damage. It also favors cell survival through its regulation of the FOXO transcription factors and the tumor suppressor gene p53. Previous studies from our laboratory have demonstrated that i) histone deacetylase SIRT1 is expressed at much higher levels in melanoma cells than in normal human epidermal melanocytes, and ii) inhibition of SIRT1 through shRNA-mediated RNA interference or sirtinol-mediated activity inhibition resulted in decreased growth, viability, and clonogenic survival of melanoma cells (Nihal et al; In: AACR Annual Meeting: Proceedings; 2011 Apr 2-6, Orlando, FL Abstract # 1647). Here, in order to determine if SIRT1 is a viable target for melanoma management, we extended our studies to determine the effects of Tenovin-1, which is a more specific and efficient small molecule inhibitor of SIRT1, in multiple melanoma cell lines, representing different stages of disease progression. For this purpose, we employed i) A375 (primary and vertical-growth tumorigenic) and HS294T (metastatic and tumorigenic), both of which are amelanotic cell lines, and ii) G361 (metastatic and tumorigenic) melanin-producing cell line. We determined the effects of Tenovin-1 on the expression levels of SIRT1 protein in melanoma cells. Our data demonstrated that Tenovin-1 treatment resulted in a dose dependent decrease in the level of SIRT1 protein in all the melanoma cell lines tested. Further, we found that Tenovin-1 treatment resulted in a concentration dependent decrease in the growth and viability of melanoma cells, as shown by Trypan blue exclusion and MTT analyses. Furthermore, we found that Tenovin-1 caused an increase in protein level of the tumor suppressor p53 in a concentration-dependent fashion. Taken together, our results suggested that Tenovin-1 reduces melanoma cell growth via inhibition of SIRT1 and subsequent increase in p53 activity. However, additional studies are needed to confirm our results and to further establish the mechanism of how Tenovin-1 mediated SIRT1 inhibition leads to melanoma cell death. This includes the evaluation of other known SIRT1 targets such as the FOXO transcription factors. Finally, in vivo studies are also required to further determine the clinical relevance of our findings.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4722. doi:1538-7445.AM2012-4722

Resveratrol restores Nrf2 level and prevents ethanol-induced toxic effects in the cerebellum of a rodent model of fetal alcohol spectrum disorders

In humans, ethanol exposure during pregnancy produces a wide range of abnormalities in infants collectively known as fetal alcohol spectrum disorders (FASD). Neuronal malformations in FASD manifest as postnatal behavioral and functional disturbances. The cerebellum is particularly sensitive to ethanol during development. In a rodent model of FASD, high doses of ethanol (blood ethanol concentration 80 mM) induces neuronal cell death in the cerebellum. However, information on potential agent(s) that may protect the cerebellum against the toxic effects of ethanol is lacking. Growing evidence suggests that a polyphenolic compound, resveratrol, has antioxidant and neuroprotective properties. Here we studied whether resveratrol (3,5,4'-trihydroxy-trans-stilbene), a phytoalexin found in red grapes and blueberries, protects the cerebellar granule neurons against ethanol-induced cell death. In the present study, we showed that administration of resveratrol (100 mg/kg) to postnatal day 7 rat pups prevents ethanol-induced apoptosis by scavenging reactive oxygen species in the external granule layer of the cerebellum and increases the survival of cerebellar granule cells. It restores ethanol-induced changes in the level of transcription factor nuclear factor-erythroid derived 2-like 2 (nfe2l2, also known as Nrf2) in the nucleus. This in turn retains the expression and activity of its downstream gene targets such as NADPH quinine oxidoreductase 1 and superoxide dismutase in cerebellum of ethanol-exposed pups. These studies indicate that resveratrol exhibits neuroprotective effects in cerebellum by acting at redox regulating proteins in a rodent model of FASD.

Resveratrol prevents embryonic oxidative stress and apoptosis associated with diabetic embryopathy and improves glucose and lipid profile of diabetic dam

SCOPE

Diabetic embryopathy, a consequence of diabetic pregnancy, is associated with increase in embryonic oxidative stress and apoptosis, which lead to severe embryonic damage at early stage of organogenesis.

METHODS AND RESULTS

This study investigated if resveratrol, found in red grapes and blue-berries, may prevent diabetes-induced oxidative stress and apoptosis in embryos and have beneficial effects in diabetic dams. A rodent model of diabetic embryopathy was used. Diabetes was associated with lowered reduced glutathione levels (26.98%), increased total thiol (100.47%) and lipid peroxidation (124.73%) in embryos, and increased blood sugar (384.03%), cholesterol (98.39%) and triglyceride (1025.35%) in diabetic dams. Increased apoptosis (272.20%) was also observed in the embryos of diabetic dams. Administration of resveratrol (100 mg/kg body weight (b.w.)) during pregnancy prevented both oxidative stress and apoptosis in embryos. Resveratrol reduced embryonic maldevelopment by improving embryo weight (41.23%), crown rump length (16.50%) and somite number (11.22%). It further improved the glucose (33.32%) and lipid (cholesterol 41.74%, triglyceride 60.64%) profile of the diabetic dams, which also represents the protective role of resveratrol in diabetes.

CONCLUSION

Resveratrol was found to prevent embryonic oxidative stress and apoptosis. It also improved glucose and lipid profile of diabetic dams, indicating the beneficial effects in diabetic pregnancy.

Ethanol impairs activation of retinoic acid receptors in cerebellar granule cells in a rodent model of fetal alcohol spectrum disorders

BACKGROUND

Ethanol is the main addictive and neurotoxic constituent of alcohol. Ethanol exposure during embryonic development causes dysfunction of the central nervous system (CNS) and leads to fetal alcohol spectrum disorders. The cerebellum is one of the CNS regions that are particularly vulnerable to ethanol toxic effects. Retinoic acid (RA) is a physiologically active metabolite of vitamin A that is locally synthesized in the cerebellum. Studies have shown that RA is required for neuronal development, but it remains unknown if ethanol impairs RA signaling and thus induces neuronal malformations. In this study, we tested the hypothesis that ethanol impairs the expression and activation of RA receptors in cerebellum and in cerebellar granule cells.

METHODS

The cerebellum of ethanol unexposed and exposed pups was used to study the expression of retinoic acid receptors (RARs or RXRs) by immunohistochemistry and by Western blot analysis. We also studied the effect of ethanol on expression of RA receptors in the cerebellar granule cells. Activation of RA receptors (DNA-binding activities) in response to high-dose ethanol was determined by electrophoretic mobility shift and supershift assays.

RESULTS

Findings from these studies demonstrated that ethanol exposure reduced the expression of RARalpha/gamma while it increased the expression of RXRalpha/gamma in the cerebellum and in cerebellar granule neurons. Immuno-histological studies further strengthened the expression pattern of RA receptors in response to ethanol. The DNA-binding activity of RARs was reduced, while DNA-binding activity of RXRs was increased in response to ethanol exposure.

CONCLUSION

For the first time, our studies have demonstrated that high-dose ethanol affects the expression and activation of RA receptors, which could impair the signaling events and induce harmful effects on the survival and differentiation of cerebellar granule cells. Taken together, these findings could provide insight into the treatment options for brain defects caused by excessive ethanol exposure, such as in Fetal Alcohol Spectrum Disorders.

Studies on the removal of Pb(II) from wastewater by activated carbon developed from Tamarind wood activated with sulphuric acid

The low-cost activated carbon were prepared from Tamarind wood material by chemical activation with sulphuric acid for the adsorption of Pb(II) from dilute aqueous solution. The activated carbon developed shows substantial capacity to adsorb Pb(II) from dilute aqueous solutions. The parameters studied include physical and chemical properties of adsorbent, pH, adsorbent dose, contact time and initial concentrations. The kinetic data were best fitted to the Lagergren pseudo-first-order and pseudo-second order models. The isotherm equilibrium data were well fitted by the Langmuir and Freundlich models. The maximum removal of lead(II) was obtained 97.95% (experimental) and 134.22 mg/g (from Langmuir isotherm model) at initial concentration 40 mg/l, adsorbent dose 3g/l and pH 6.5. This high uptake showed Tamarind wood activated carbon as among the best adsorbents for Pb(II).

Rabies in South Asia: epidemiological investigations and clinical perspective

A five year study (1995-1999) was conducted in Northern India to investigate epidemiological aspects of rabies in domestic animals. For this purpose, brain tissue samples were collected from rabies suspect animals including 231 dogs, 79 buffaloes, 46 cattle and 28 wild species. Out of the 384 rabies suspected cases, 56% were positive for rabies by fluorescent antibody test (FAT), the mouse inoculation test (MIT) and histopathological techniques. Variations in clinical signs of rabies were recorded for individual animals with significant differences observed between dogs and bovines with respect to hypersalivation, paralysis, recognition of owners and aggression. Likewise, differences in the clinical course of disease between cows and buffaloes regarding hypersalivation and micturition were observed. Rabies incidence was highest among adult male dogs and indicated a seasonal pattern with more rabies cases during certain months of the year (January to April, and August to November). Its impact on cow/buffalo rabies is discussed. Accumulated history records revealed that 78% of owned rabid dogs were not prophylactically vaccinated against rabies.

Detection and characterization of recombinant DNA expressing vip3A-type insecticidal gene in GMOs--standard single, multiplex and construct-specific PCR assays

Vegetative insecticidal protein (Vip), a unique class of insecticidal protein, is now part of transgenic plants for conferring resistance against lepidopteron pests. In order to address the imminent regulatory need for detection and labeling of vip3A carrying genetically modified (GM) products, we have developed a standard single PCR and a multiplex PCR assay. As far as we are aware, this is the first report on PCR-based detection of a vip3A-type gene (vip-s) in transgenic cotton and tobacco. Our assay involves amplification of a 284-bp region of the vip-s gene. This assay can possibly detect as many as 20 natural wild-type isolates bearing a vip3A-like gene and two synthetic genes of vip3A in transgenic plants. The limit of detection as established by our assay for GM trait (vip-s) is 0.1%. Spiking with nontarget DNA originating from diverse plant sources had no inhibitory effect on vip-s detection. Since autoclaving of vip-s bearing GM leaf samples showed no deterioration/interference in detection efficacy, the assay seems to be suitable for processed food products as well. The vip-s amplicon identity was reconfirmed by restriction endonuclease assay. The primer set for vip-s was equally effective in a multiplex PCR assay format (duplex, triplex and quadruplex), used in conjunction with the primer sets for the npt-II selectable marker gene, Cauliflower mosaic virus 35S promoter and nopaline synthetase terminator, enabling concurrent detection of the transgene, regulatory sequences and marker gene. Further, the entire transgene construct was amplified using the forward primer of the promoter and the reverse primer of the terminator. The resultant amplicon served as a template for nested PCR to confirm the construct integrity. The method is suitable for screening any vip3A-carrying GM plant and food. The availability of a reliable PCR assay method prior to commercial release of vip3A-based transgenic crops and food would facilitate rapid and efficient regulatory compliance.

Detection and characterization of cry1Ac transgene construct in Bt cotton: multiple polymerase chain reaction approach

To comply with international labeling regulations for genetically modified (GM) crops and food, and to enable proper identification of GM organisms (GMOs), effective methodologies and reliable approaches are needed. The spurious and unapproved GM planting has contributed to crop failures and commercial losses. To ensure effective and genuine GM cultivation, a methodology is needed to detect and identify the trait of interest and concurrently evaluate the structural and functional stability of the transgene insert. A multiple polymerase chain reaction (PCR) approach was developed for detection, identification, and gene stability confirmation of cry1Ac transgene construct in Bt cotton. As many as 9 samples of Bt cotton hybrid seeds comprising 3 approved Bt hybrids, MECH-12Bt, MECH-162Bt, MECH-184Bt, and a batch of 6 nonapproved Bt hybrids were tested. Initially, single standard PCR assays were run to amplify predominant GM DNA sequences (CaMV 35S promoter, nos terminator, and npt-II marker gene); a housekeeping gene, Gossypium hirsutum fiber-specific acyl carrier protein gene (acp1); a trait-specific transgene (cry1Ac); and a sequence of 7S 3' transcription terminator which specifically borders with 3' region of cry1Ac transgene cassette. The concurrent amplification of all sequences of the entire cassette was performed by 3 assays, duplex, triplex, and quadruplex multiplex PCR assays, under common assay conditions. The identity of amplicons was reconfirmed by restriction endonuclease digestion profile. The 2 distinct transgene cassettes, cry1Ac and npt-II, of the Bt cotton were amplified using the respective forward primer of promoter and reverse primer of terminator. The resultant amplicons were excised, eluted, and purified. The purified amplicons served as template for nested PCR assays. The nested PCR runs confirmed the transgene construct orientation and identity. The limit of detection as established by our assay for GM trait (cry1Ac) was 0.1%. This approach can be adopted as a standard procedure for complete molecular characterization of Bt cotton. These assays will be of interest and use to importers, breeders, research laboratories, safety regulators, and food processors for detection of cry1Ac bearing GMOs.

Study of spermatozoa and their relationship with fertility in men of Arunachal Pradesh

172 semen samples were collected from a cross section of the infertile population of North-East India, consisting mainly of tribal people and were analysed and evaluated for different parameters. Significant negative correlations were found between sperm count and motility, sperm count and morphology and between motility and abnormal morphology in this series. The percentage of abnormal morphology was very high and prospective study on the aetiology of this factor in these tribal people is warranted.

Interaction of pea (Pisum sativum L.) lectins with rhizobial strains

Lectins from two varieties (PG-3 and LFP-48) of pea have been purified by affinity chromatography on Sephadex G-50. The specific activity increased by 23 and 25 folds, respectively. These lectins from both the varieties were found to be specific for mannose. The purified fluorescein isothiocyanate (FITC)-labelled lectins showed binding reaction with homologous as well as heterologous strains of Rhizobium spp. The results revealed that pea lectins are not highly specific to their respective rhizobia. Moreover, these lectins showed a greater stimulatory effect on homologous Rhizobium leguminosarum strains.

Effect of potash alum (aluminium potassium sulphate) on human semen and sperm

25 normal and healthy human volunteers were engaged in this investigation. The different concentration of potash alum solution have different effects on sperm, motility/death and fructose level of the semen. Higher concentration have higher effects.

Effect of IUCD on human uterine fluid protein concentration throughout the menstrual cycle

Uterine fluid of 96 Women implanted with IUCD was collected and processed for protein estimation. The results obtained in women having IUCD were compared with those of parous/normal women. The trend of fluctuation in protein concentration was the same in both parous and women with IUCD. But comparatively the protein concentration in it was so much higher in women having IUCD throughout the menstrual cycle. The increased concentration may be responsible for making the fluid environment unfavourable for blastocyst as well as sperm metabolism.

Cyclic variation in rats's uterine fluid phosphatase level after administration of lyndral (17 alpha-ethinyl estradiol)

An oral administration of antifertility drug Lyndral (17 alpha-ethinyl estradiol) at doses 5 micrograms/rat/a week for 3 consecutive weeks altered the internal biochemical milieu of uterus, showing a cyclic variation in both acid and alkaline phosphatase of the uterine fluid with high levels being present at proestrus and estrus in control rats. In Lyndral treated rats acid phosphatase showed a tendency to increase in estrus and metestrus rats, whereas alkaline phosphatase increased significantly during proestrus and estrus stages of the cycle. All these altered phosphatase levels in uterine fluid, after Lyndral treatment, gives some insight into the hormonal sensitiveness of these enzymes.