Combinations of SERPINB5 gene polymorphisms and environmental factors are associated with oral cancer risks

Association and functional significance of genetic variants present in regulatory elements of SERPINB5 gene in gallbladder cancer

SERPINB5 is a mammary serine protease inhibitor, which is involved in various cellular functions. The aberrant expression of SERPINB5 is reported in many cancers along with GBC but limited information is available about its role in genetic predisposition for GBC. We carried out case-control study in 206 cases and 219 controls. Promoter SNPs were genotyped by Sanger's sequencing. In-silico promoter analysis and luciferase reporter assay were done to elucidate the role of promoter variants in regulation of SERPINB5 expression. Out of four SNPs, three SERPINB5 promoter variants showed association with GBC in different models. The 'C' allele of variant rs17071138 was found to be significantly associated with GBC (p = 0.017). The 'T' allele of rs3744940 significantly increased the risk for GBC in dominant (p = 0.035) and additive models (p = 0.005). Also, rs3744941 'T' allele increased the risk for GBC by dominant (p = 0.042) as well as additive models (p = 0.016). In-silico promoter analysis and luciferase reporter assay revealed the probable regulatory role of the SERPINB5 promoter variant rs17071138 on the expression. Overall, our study reveals the genetic association of SERPINB5 promoter variants with GBC and possible role of rs17071138 in the regulation of expression.

SERPINB5 Genetic Variants rs2289519 and rs2289521 are Significantly Associated with Gallbladder Cancer Risk

Serine protease inhibitor b5 (SERPINB5) is a tumor suppressor gene that plays a critical role in various cellular processes. In gallbladder cancer (GBC), SERPINB5's aberrant expression is reported but its role in genetic predisposition is not known. We enrolled 270 cases and 296 controls and genotyped them for single nucleotide polymorphisms (SNPs) using direct DNA sequencing, followed by genotype-phenotype analysis in GBC and other cancer cell lines. Luciferase assay was done to determine the role of rs2289521 SNP on expression regulation. We found that two SERPINB5 variants rs2289519 and rs2289521 are significantly associated with GBC and contribute to genetic predisposition. The TT genotype of variant rs2289519 was found to be significantly associated (p = 0.008) with GBC in a recessive model. C allele of rs2289521 increased the risk for GBC significantly at genotypic (CT, p = 0.026) and allelic (p = 0.04) levels. In silico analysis and luciferase assay uncovered the probable regulatory role of the rs2289521 variant on expression. Genotype-phenotype correlation in GBC and breast cancer cell lines showed reduced expression of SERPINB5 in the presence of C allele that was consistent with the result of luciferase assay. Overall, our study reveals the genetic association of two SERPINB5 variants with GBC and rs2289521's possible role in the regulation of expression.

Subcellular expression of maspin – from normal tissue to tumor cells

Maspin or SerpinB5, a member of the serine protease inhibitor family, was shown to function as a tumor suppressor, especially in carcinomas. It seems to inhibit invasion, tumor cells motility and angiogenesis, and promotes apoptosis. Maspin can also induce epigenetic changes such as cytosine methylation, de-acetylation, chromatin condensation, and histone modulation. In this review, a comprehensive synthesis of the literature was done to present maspin function from normal tissues to pathologic conditions. Data was sourced from MEDLINE and PubMed. Study eligibility criteria included: Published in English, between 1994 and 2019, specific to humans, and with full-text availability. Most of the 118 studies included in the present review focused on maspin immunostaining and mRNA levels. It was shown that maspin function is organ-related and depends on its subcellular localization. In malignant tumors, it might be downregulated or negative (e.g., carcinoma of prostate, stomach, and breast) or upregulated (e.g., colorectal and pancreatic tumors). Its subcellular localization (nuclear vs cytoplasm), which can be proved using immunohistochemical methods, was shown to influence both tumor behavior and response to chemotherapy. Although the number of maspin-related papers increased, the exact role of this protein remains unknown, and its interpretation should be done with extremely high caution.

Functional variant of CHI3L1 gene is associated with neck metastasis in oral cancer

OBJECTIVES

Oral cancer is the most common head and neck malignancy, and it is associated with a high recurrence rate and lymph node metastasis potential. YKL-40, also known as chitinase-3-like protein 1 (CHI3L1), is a secreted glycoprotein that serves as a biomarker in several diseases. It also plays a crucial role in regulating many characteristics of cancer, such as cell growth, migration, anti-apoptosis, and angiogenesis. Accumulating evidence supports the link between single-nucleotide polymorphisms (SNPs) and oral cancer, but no report on the association between CHI3L1 polymorphisms and oral cancer is available. Thus, the present study evaluated the contribution of CHI3L1 SNPs to oral cancer susceptibility and clinicopathology.

MATERIALS AND METHODS

This study recruited a total of 2362 subjects, comprising 1190 healthy male controls and 1172 male patients with oral cancer. Allelic discrimination of the CHI3L1 polymorphisms - 1371 G>A (rs6691378), - 247 G>A (rs10399805), - 131 C>G (rs4950928), and + 2950 T>C (rs880633) was assessed through real-time polymerase chain reaction.

RESULTS

We detected a significant association of rs10399805 and rs6691378 with the risk of oral cancer (AOR, 1.537; 95% CI, 1.089-2.168; p = 0.014; AOR, 1.561; 95% CI, 1.131-2.156; p = 0.007, respectively) after adjustment for three potential confounders, smoking, betel nut chewing, and alcohol consumption. Moreover, we found that oral cancer patients carrying the homozygous A/A genotype of the rs10399805 (p = 0.035) or rs6691378 polymorphism (p = 0.023) showed a significantly lower risk of lymph node metastasis. Moreover, according to the Genotype-Tissue Expression database, the rs10399805 and rs6691378 polymorphisms in the promoter region were associated with decreased levels of CHI3L1 mRNA.

CONCLUSIONS

In conclusion, we found that the homozygous mutant allele of rs10399805 and rs6691378 appeared to have significantly lower risk of lymph node metastasis and associated with its mRNA levels in oral cancer.

CLINICAL RELEVANCE

The CHI3L1 polymorphisms rs10399805 and rs6691378 may act as biomarkers for predicting lymph node metastasis in oral cancer patients.