LxCxD motif of the APC/C coactivator subunit FZR1 is critical for interaction with the retinoblastoma protein.

Retinoblastoma protein (pRB) regulates cell cycle by utilizing different regions of its pocket domain for interacting with E2F family of transcription factors and with cellular and viral proteins containing an LxCxE motif. An LxCxE-like motif, LxCxD, is present in FZR1, an adaptor protein of the multi-subunit E3 ligase complex anaphase-promoting complex/cyclosome (APC/C). The APC/CFZR1 complex regulates the timely degradation of multiple cell cycle proteins for mitotic exit and maintains G1 state. We report that FZR1 interacts with pRB via its LxCxD motif. By using point mutations, we found that the cysteine residue in the FZR1 LxCxD motif is critical for direct interaction with pRb. The direct binding of the LxCxD motif of FZR1 to the pRB LxCxE binding pocket is confirmed by using human papillomavirus protein E7 as a competitor, both in vitro and in vivo. While mutation of the cysteine residue significantly disrupts FZR1 interaction with pRB, this motif does not affect FZR1 and core APC/C association. Expression of the FZR1 point mutant results in accumulation of S-phase kinase-associated protein 2 (SKP2) and Polo-like kinase 1 (PLK1), while p27Kip1 and p21Cip1 proteins are downregulated, indicating a G1 cell cycle defect. Consistently, cells containing point mutant FZR1 enter the S phase prematurely. Together our results suggest that the LxCxD motif of FZR1 is a critical determinant for the interaction between FZR1 and pRB and is important for G1 restriction.

The Demographic Diversity of Food Intake and Prevalence of Kidney Stone Diseases in the Indian Continent.

Food intake plays a pivotal role in human growth, constituting 45% of the global economy and wellbeing in general. The consumption of a balanced diet is essential for overall good health, and a lack of equilibrium can lead to malnutrition, prenatal death, obesity, osteoporosis and bone fractures, coronary heart diseases (CHD), idiopathic hypercalciuria, diabetes, and many other conditions. CHD, osteoporosis, malnutrition, and obesity are extensively discussed in the literature, although there are fragmented findings in the realm of kidney stone diseases (KSD) and their correlation with food intake. KSD associated with hematuria and renal failure poses an increasing threat to healthcare infrastructures and the global economy, and its emergence in the Indian population is being linked to multi-factorial urological disorder resulting from several factors. In this realm, epidemiological, biochemical, and macroeconomic situations have been the focus of research, even though food intake is also of paramount importance. Hence, in this article, we review the corollary associations with the consumption of diverse foods and the role that these play in KSD in an Indian context.

Polymorphisms in ADH1B and ALDH2 genes associated with the increased risk of gastric cancer in West Bengal, India.

BACKGROUND: Gastric cancer (GC) is one of the most frequently diagnosed digestive tract cancers and carries a high risk of mortality. Acetaldehyde (AA), a carcinogenic intermediate of ethanol metabolism contributes to the risk of GC. The accumulation of AA largely depends on the activity of the major metabolic enzymes, alcohol dehydrogenase and aldehyde dehydrogenase encoded by the ADH (ADH1 gene cluster: ADH1A, ADH1B and ADH1C) and ALDH2 genes, respectively. This study aimed to evaluate the association between genetic variants in these genes and GC risk in West Bengal, India. METHODS: We enrolled 105 GC patients (cases), and their corresponding sex, age and ethnicity was matched to 108 normal individuals (controls). Genotyping for ADH1A (rs1230025), ADH1B (rs3811802, rs1229982, rs1229984, rs6413413, rs4147536, rs2066702 and rs17033), ADH1C (rs698) and ALDH2 (rs886205, rs968529, rs16941667 and rs671) was performed using DNA sequencing and RFLP. RESULTS: Genotype and allele frequency analysis of these SNPs revealed that G allele of rs17033 is a risk allele (A vs G: OR = 3.67, 95% CI = 1.54-8.75, p = 0.002) for GC. Significant association was also observed between rs671 and incidence of GC (p = 0.003). Moreover, smokers having the Lys allele of rs671 had a 7-fold increased risk of acquiring the disease (OR = 7.58, 95% CI = 1.34-42.78, p = 0.009). CONCLUSION: In conclusion, rs17033 of ADH1B and rs671 of ALDH2 SNPs were associated with GC risk and smoking habit may further modify the effect of rs671. Conversely, rs4147536 of ADH1B might have a protective role in our study population. Additional studies with a larger patient population are needed to confirm our results.

Genetic Alterations in Pendrin (SLC26A4) Gene in Adult Hypothyroid Patients.

Current study was aimed to screen the SLC26A4 gene in 127 nonautoimmune and noncongenital hypothyroid patients, who were under optimal iodine nutrition and devoid of any characteristics of Pendred syndrome from eastern part of Indian population. 8 single nucleotide variants/mutations were identified in heterozygous state in 20% patient population, which include 1 novel nonsynonymous (p.C18S), 1 novel intronic (g.942C>A), 3 known nonsynonymous (p.S23X, p.V239D, and p.I455F), and 3 known intronic (g.23034G>T, g.29641C>G, and g.33893T>C) variants. Only g.23034G>T was noted also in homozygous state in 2% patient population. However, Controls exhibited only the variations g.23034G>T and p.I455F. Therefore, present study reports for the first time that the observed novel variants in pendrin gene might be linked with autoimmune negative hypothyroidism, without any characteristics of Pendred syndrome and/or congenital hypothyroidism. While, all observed known variants/mutations were reported with either Pendred syndrome and/or congenital hypothyroidism earlier, but never with nonautoimmune adult hypothyroidism solely. Thereby, the absence of any features of Pendred syndrome and/or congenital hypothyroidism in patients with observed known nonsynonymous variants/mutations may be due to either heterozygous state of each variant or differential domain specific activity of ions trafficking in the respective organ. The analysis of amino acid change at least for p.C18S, p.S23X, and p.V239D in correlation with phenotypic characteristics of respective patients might assume a possible effect on protein structure and function. Altogether, we report for the first time that genetical variations in SLC26A4 gene could play an important role in development of nonautoimmune adult hypothyroidism.

Association of calcitonin receptor gene (CALCR) polymorphism with kidney stone disease in the population of West Bengal, India.

Kidney Stone Disease (KSD) is a complex urologic disorder with strong genetic constituent. Earlier association studies have indicated that the genetic polymorphisms are the potential cause of stone materialization; however unfortunately, the actual genetic signature is still unknown. Therefore, present study was aimed to investigate the potential contribution of two important polymorphisms of calcitonin receptor gene (CALCR): (i) rs1801197 (Leu447Pro) and (ii) rs1042138 (3'UTR+18C>T) in renal stone formation. Accordingly, we enrolled 152 patients registered with calcium-rich stone in kidney (case) and 144 corresponding age, sex and ethnicity matched healthy individuals (controls). Epidemiological and clinical data were recorded as well as peripheral blood sample was collected from each individual. Serum creatinine and urinary calcium level was found high in patients, compared to controls. Out of two studied polymorphisms, we have not found any significant association against the rs1042138 with KSD, nonetheless, significant high frequency (p=0.001; Odds ratio=1.81; 95% CI: 1.28-2.55) of risk allele T against the rs1801197 (T>C) in patient was noted. Moreover, significant association with KSD was noted by genotypic analysis of rs1801197 (Leu447Pro) in our population. Interestingly, male patients carrying TT genotype was found to be at high risk of stone formation, while no such association was observed in female patients. Altogether, present study indicated that the rs1042138 might not be used as a useful marker for susceptibility of kidney stone formation, whereas, the rs1801197 could definitely be considered as one of the risk factors for KSD in Indian population at least in West Bengal in particular.

Association of DNA repair and xenobiotic pathway gene polymorphisms with genetic susceptibility to gastric cancer patients in West Bengal, India.

Gastric cancer is one of the most common malignancies in India. DNA repair gene or xenobiotic pathway gene polymorphisms have recently been shown to affect individual susceptibility to gastric cancer. Here, the possible interaction between common polymorphisms in X-ray repair cross complementing group I (XRCC1) gene and glutathione S-transferase (GST) genes (GSTM1, GSTT1 and GSTP1), smoking and alcohol consumption and overall survival in gastric cancer patients were evaluated. In this population-based case control study, 70 gastric cancer patients and 82 healthy controls were enrolled. The epidemiological data were collected by a standard questionnaire, and blood samples were collected from each individual. XRCC1 Arg194Trp, Arg280His and Arg399Gln polymorphisms were determined by polymerase chain reaction and direct DNA sequencing. GSTM1 and GSTT1 null polymorphisms and GSTP1 Ile105Val polymorphism were identified by multiplex polymerase chain reaction and restriction fragment length polymorphism (RFLP), respectively. The risk of gastric cancer was significantly elevated in individuals with XRCC1 Arg/Gln +Gln/Gln (p = 0.031; odds ratio = 2.32; 95 % confidence interval (CI) 1.07-5.06) and GSTP1 Val/Val genotype (p = 0.009; odds ratio = 8.64; 95 % CI 1.84-40.55). An elevated risk for GC was observed in smokers and alcohol consumers carrying GSTP1 Ile/Val +Val/Val genotype (p = 0.041; odds ratio = 3.71; 95 % CI 0.98-14.12; p = 0.002; odds ratio = 12.31; 95 % CI 1.71-88.59). These findings suggest that XRCC1 rs25487 and GSTP1 rs1695 can be considered as a risk factor associated with gastric cancer and might be used as a molecular marker for evaluating the susceptibility of the disease.

Polymorphisms in CaSR and CLDN14 Genes Associated with Increased Risk of Kidney Stone Disease in Patients from the Eastern Part of India.

Kidney stone disease (KSD) is a major clinical problem imposing a large burden for both healthcare and economy globally. In India, the prevalence of kidney stone disease is rapidly increasing. This study aimed to evaluate the association between genetic defects in vitamin D receptor (VDR), calcium sensing receptor (CaSR) and claudin 14 (CLDN14) genes and kidney stone disease in patients from eastern India. We enrolled 200 consecutive kidney stone patients (age 18-60 years) (cases) and their corresponding sex and age matched 200 normal individuals (controls). To identify genetic variants responsible for KSD, we performed sequence analysis of VDR, CaSR and CLDN14 genes. Four non-synonymous (rs1801725, rs1042636, rs1801726 and rs2228570), one synonymous (rs219780) and three intronic single nucleotide polymorphisms (SNPs) (rs731236, rs219777 and rs219778) were identified. Genotype and allele frequency analysis of these SNPs revealed that, rs1801725 (Ala986Ser), rs1042636 (Arg990Gly) of CaSR gene and rs219778, rs219780 (Thr229Thr) of CLDN14 gene were significantly associated with KSD. Serum calcium levels were significantly higher in subjects carrying 986Ser allele and calcium excretion was higher in subjects bearing 990Gly allele. In conclusion, rs1801725, rs1042636, rs219778 and rs219780 SNPs were associated with kidney stone risk in patients from the eastern part of India.