Dhruva Mishra

Global Methylation Pattern of Genes in Androgen-Sensitive and Androgen-Independent Prostate Cancer Cells

Promoter DNA methylation of CpG islands is an important epigenetic mechanism in cancer development. We have characterized the promoter methylation profile of 82 genes in three prostate cancer cell lines (LNCaP, PC3, and DU145) and two normal prostate cell lines (RWPE1 and RWPE2). The methylation pattern was analyzed using a Panomics gene array system that consists of immobilized probes of known gene promoters on a nitrocellulose membrane. Methylation binding protein–purified methylated DNA was hybridized on the membrane and detected by the chemiluminescence method. We analyzed methylation profile in normal (RWPE1) versus cancerous cells and androgen receptor (AR)–sensitive (LNCaP) versus AR-negative cells (DU145 and PC3). Our study shows that >50% of the genes were hypermethylated in prostate cancer cells compared with 13% in normal cell lines. Among these were the tumor suppressor (RB, TMS1, DAPK, RBL1, PAX6, and FHIT), cell cycle (p27KIP1 and CDKN2A), transporters (MDR1, MLC1, and IGRP), and transcription factor (STAT1, CIITA, MYOD, and NPAT) genes. Relative methylation pattern shows that most of these genes were methylated from 5-fold to >10-fold compared with the normal prostate cells. In addition, promoter methylation was detected for the first time in target genes such as RIOK3, STAT5, CASP8, SRBC, GAGE1, and NPAT. A significant difference in methylation pattern was observed between AR-sensitive versus AR-negative cancer cells for the following genes: CASP8, GPC3, CD14, MGMT, IGRP, MDR1, CDKN2A, GATA3, and IFN. In summary, our study identified candidate genes that are methylated in prostate cancer. Mol Cancer Ther; 9(1); 33–45

Vitamin D Receptor Gene Polymorphisms and Prognosis of Breast Cancer among African-American and Hispanic Women

Background Vitamin D plays a role in cancer development and acts through the vitamin D receptor (VDR). Although African-Americans have the lowest levels of serum vitamin D, there is a dearth of information on VDR gene polymorphisms and breast cancer among African-Americans and Hispanics. This study examines whether VDR gene polymorphisms are associated with breast cancer in these cohorts. Methods Blood was collected from 232 breast cancer patients (Cases) and 349 non-cancer subjects (Controls). Genotyping for four polymorphic variants of VDR (FokI, BsmI, TaqI and ApaI) was performed using the PCR-RFLP method. Results An increased association of the VDR-Fok1 f allele with breast cancer was observed in African-Americans (OR = 1.9, p = 0.07). Furthermore, the FbTA, FbtA and fbtA haplotypes were associated with breast cancer among African-Americans (p<0.05). Latinas were more likely to have the VDR-ApaI alleles (Aa or aa) (p = 0.008). The VDR-ApaI aa genotype was significantly associated with poorly-differentiated breast tumors (p = 0.04) in combined Cases. Kaplan-Meier survival analysis showed decreased 5-year disease-free-survival (DFS) in breast cancer patients who had the VDR-Fok1 FF genotype (p<0.05). The Cox regression with multivariate analysis revealed the independent predictor value of the VDR-FokI polymorphism for DFS. The other three variants of VDR (BsmI, TaqI and ApaI) were not associated with disease outcome. Conclusions VDR haplotypes are associated with breast cancer in African-Americans, but not in Hispanic/Latinas. The VDR-FokI FF genotype is linked with poor prognosis in African-American women with breast cancer.

Vitamin D receptor FokI gene polymorphisms may be associated with colorectal cancer among African American and Hispanic participants

Vitamin D plays a role in cancer tumorogenesis and acts through the vitamin D receptor (VDR). Although African Americans have the lowest serum vitamin D levels, supplementation has not yielded a significant improvement in cancer. Gene polymorphisms in VDR may play a role. There is a dearth of information on VDR gene polymorphisms and colorectal cancer (CRC) among under‐represented ethnic groups. In this study, the authors examined whether VDR gene single nucleotide polymorphisms (SNPs) were associated with CRC in predominately African American and Hispanic study participants.

IGF gene polymorphisms and breast cancer in African-American and Hispanic women

Previous studies from our group and others have shown that increased circulatory levels of the ligand insulin-like growth factor 1 (IGF-1) and decreased levels of the predominant IGF-1 binding protein 3 (IGFBP-3) are associated with an increased incidence of breast cancer and poor outcome. Some studies suggest that, in addition to the influence of environmental factors on the levels of IGF-1 and IGFBP-3, alterations in their gene polymorphisms may play a significant role in the risk of cancer. In this study, we investigated the association between gene polymorphisms along the IGF axis and breast cancer, including the IGF-1 (CA) dinucleotide repeat, IGFBP-3 A-202C single nucleotide polymorphism, and the 2-bp deletion and (AGG)n repeat polymorphisms in the IGF type 1 receptor (IGF-IR). A total of 654 subjects, including both African-American and Hispanic/Latino subjects, were screened for various gene polymorphisms. IGF gene polymorphism genotyping was performed by PCR-GeneScan and PCR-RFLP methods. Our results demonstrated a significant association between the non-19/non-19 IGF-1 (CA)n polymorphism and breast cancer (OR = 1.75; 95% CI = 1.07-2.88; P = 0.027). Furthermore, absence of the wild-type-19 allele and alleles <(CA)19 were strongly associated with breast cancer (OR = 1.82; 95% CI = 1.20-2.77; P = 0.005 and OR = 1.70; 95% CI = 1.19-2.43; P = 0.003, respectively). The association of the non-19/non-19 polymorphism with breast cancer was also more significant in premenopausal women (P = 0.04). We did not find any significant association of the IGFBP-3 polymorphism with breast cancer. In the case of IGF-1R polymorphisms, the only significant trend was in the (AGG)5 allele; however, the frequency of this allele was very rare. In summary, our study demonstrated a significant association of IGF-1 polymorphisms and breast cancer. Future studies are necessary to understand the mechanistic value of these polymorphisms in breast cancer risk.

Abstract 1278: Vitamin D receptor Fok1 gene polymorphisms may be associated with CRC among African American and Hispanic participants

Background: The vitamin D pathway plays a significant role through the vitamin D receptor (VDR) in cancer tumorogenesis. Interestingly, although African Americans have the lowest levels of vitamin D serum levels, vitamin D supplementation has not yielded significant improvement in cancer risk and outcome. Gene polymorphisms in VDR may play a role. There is lack of information on VDR gene polymorphisms and colorectal cancer (CRC) among underrepresented ethnic groups. Hence, this study is among the first to examine whether VDR SNPs, single-nucleotide-gene-polymorphisms, are associated with CRC in predominately African American and Hispanic study participants. Methods: A total of 378 participants were included in the study with 78 CRC patients and 300 non-CRC participants. Forty percent of participants were African American, 56% were Hispanic/Latino, and the remainder of participants self-identified as Caucasian or Asian. The four polymorphic SNPs in VDR - FokI (rs2228570), BsmI (rs1544410), TaqI (rs731236) and ApaI (rs7975232) - were genotyped by polymerase chain reaction and restriction fragment length polymorphism methods. Statistical Analysis was performed by using SPSS software. Results: There was a significant difference in the distribution of the VDR-Fok1 and VDR-Apa1polymorphisms between African American and Hispanic participants (P=0.006 and 0.009, respectively). Furthermore, the VDR-Fok1 FF genotype was associated with CRC (OR=2.9; P=0.036) when compared with Controls without polyps. Upon breakdown by ethnicity, the FF genotype was most common in African American participants (61%), and the Ff genotype was most common in Hispanic/Latino participants (49%). When the association was assessed in a multivariate model, there was no significant association with any VDR polymorphism and CRC Cases (P>0.05). The other three polymorphic variants of VDR (BsmI, TaqI and ApaI) were not associated with CRC in any of the analyses. Conclusions: This study suggests that genetic variation of the VDR-FokI SNPs may influence CRC risk, particularly in African American cohorts. These findings suggest the potential need to screen for VDR polymorphisms in conjunction with screening vitamin D serum levels. As a potentially modifiable risk factor, vitamin D and the VDR mediated axis may be a point of significant interventional opportunity to effectively reduce CRC risk, with the overarching goal to reduce cancer health disparities. Citation Format: Marianna Sarkissyan, Yanyuan Wu, Zuijan Chen, Dhruva Mishra, Suren Sarkissyan, Ioannis Giannikopoulos, Jaydutt V. Vadgama. Vitamin D receptor Fok1 gene polymorphisms may be associated with CRC among African American and Hispanic participants. [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 1278. doi:10.1158/1538-7445.AM2014-1278

Abstract B44: Vitamin D receptor Fok1 gene polymorphisms are associated with colorectal cancer among African American and Hispanic participants

Background: Vitamin D plays a role in cancer and acts through the vitamin D receptor (VDR). There is a dearth of information on VDR gene polymorphisms and colorectal cancer among African-American and other underrepresented groups who also have hypovitaminosis D. This study examines whether VDR SNPs, single nucleotide gene polymorphisms (Fok1, Bsm1, Apa1, and Taq1), are associated with colorectal cancer in African-American and Hispanic study participants. Methods: DNA for genotyping was extracted from blood collected from N=378 participants (N=78 colorectal cancer patients (Cases), N=230 non-cancer subjects with no polyps (Controls w/o polyps), and N=70 non-cancer subjects with polyps (Controls w/polyp). A total of N = 149 (39.4%) participants self-identified as African-American, N = 212 (56.1%) as Hispanic/Latino, N = 9 (2.4%) as Caucasian, and N = 8 (2.1%) as Asian. The four polymorphic SNPs in VDR (FokI, BsmI, TaqI and ApaI) were assessed using the PCR-RFLP method. Results: There was a significant association of the VDR-Fok1 FF genotype with colorectal cancer Cases (OR=2.9; P=0.036) when compared with Controls w/o polyps. The most common VDR-Fok1 genotype in the overall study population was the FF genotype (46%). However, upon breakdown by ethnicity, the FF was the most common in African-American participants (61%), and the Ff was most common in Hispanic/Latino participants (49%). When the association was assessed in a multivariate model adjusting for ethnicity, gender, age, BMI, and diagnosis, there was no significant association with any VDR polymorphism and colorectal cancer Cases (P>0.05). There was also an association of the VDR-Fok1 polymorphism with metastasis (P=0.011), but not tumor size, lymph node involvement, or Duke Stage (P>0.05). The other three polymorphic variants of VDR (BsmI, TaqI and ApaI) were not associated with colorectal cancer. Conclusions: This study suggests that genetic variation at the VDR locus, in particular VDR-FokI SNPs, may influence colorectal cancer risk in the present underrepresented patient cohort. Specifically, the FF genotype is associated with Cases and was more prevalent in African-American participants, and may contribute to cancer health disparities. Additional studies are warranted to examine whether the VDR-Fok1 polymorphism assessed in combination with vitamin D levels may provide better insights into the role of VDR polymorphisms in risk and outcome from colorectal cancer. Citation Format: Marianna Sarkissyan, Yanyuan Wu, Zujian Chen, Dhruva Mishra, Jaydutt V. Vadgama. Vitamin D receptor Fok1 gene polymorphisms are associated with colorectal cancer among African American and Hispanic participants. [abstract]. In: Proceedings of the Sixth AACR Conference: The Science of Cancer Health Disparities; Dec 6–9, 2013; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2014;23(11 Suppl):Abstract nr B44. doi:10.1158/1538-7755.DISP13-B44

Vitamin D receptor FokI gene polymorphisms may be associated with colorectal cancer among African American and Hispanic participants: VDR Polymorphisms in CRC

Vitamin D plays a role in cancer tumorogenesis and acts through the vitamin D receptor (VDR). Although African Americans have the lowest serum vitamin D levels, supplementation has not yielded a significant improvement in cancer. Gene polymorphisms in VDR may play a role. There is a dearth of information on VDR gene polymorphisms and colorectal cancer (CRC) among under‐represented ethnic groups. In this study, the authors examined whether VDR gene single nucleotide polymorphisms (SNPs) were associated with CRC in predominately African American and Hispanic study participants.

Vitamin D receptor Fok1 gene polymorphisms may be associated with CRC among African American and Hispanic participants

Vitamin D plays a role in cancer tumorogenesis and acts through the vitamin D receptor (VDR). Although African Americans have the lowest serum vitamin D levels, supplementation has not yielded a significant improvement in cancer. Gene polymorphisms in VDR may play a role. There is a dearth of information on VDR gene polymorphisms and colorectal cancer (CRC) among under‐represented ethnic groups. In this study, the authors examined whether VDR gene single nucleotide polymorphisms (SNPs) were associated with CRC in predominately African American and Hispanic study participants.

Abstract 878: Comorbidities in African American and Hispanic/Latina Breast Cancer Patients are associated with IGF-1 and IGFBP3-3 Gene Polymorphisms

Increase in comorbidities such as diabetes and hypertension in cancer patients lead to poor disease free survival and overall survival. It is probable that risk factors associated with these comorbidities and cancer itself could be linked to alterations in gene polymorphisms associated with hormones and/or growth factors. In this study, we have investigated if (1) comorbidities were associated with our African American and Hispanic breast cancer subjects; and (2) if there was any association between Insulin-Like Growth Factor 1 (IGF-1), and IGF Binding Protein 3 (IGFBP3) gene polymorphisms with breast cancer and comorbidities. We studied 514 subjects (175 African Americans and 339 Hispanic/Latinas), which included 208 cases and 306 controls (no evidence of breast cancer) subjects. DNA was extracted from blood samples and IGF-1 and IGFBP-3 genotyping was performed by PCR-GeneScan and PCR-RFLP methods, respectively. Our results demonstrated that comorbidity is significantly correlated with breast cancer (OR = 2.12; 95% CI = 1.40-3.21; P-value Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 878.