Gallbladder cancer-associated genetic variants rs1003349 and rs1004030 regulate MMP14 expression by altering SOX10- and MYB-binding sites.

The pathogenesis of gallbladder cancer is complex, involving environmental and genetic risk factors. The matrix metallopeptidase 14 (MMP14) alters the tumor microenvironment and promotes tumorigenesis. In this study, we have characterized the role of the MMP14 promoter variants rs1004030 and rs1003049 in gallbladder cancer pathogenesis. Previously, we have shown the association of rs1004030 and rs1003049 with GBC and allele-specific differential expression of MMP14 in GBC patients. These variants reside within the cis-regulatory element (CRE) with high DNase and H3K4me3 signals, suggesting an active regulatory role in MMP14 expression. The luciferase-based reporter assay showed the role of promoter variants on expression levels in two GBC cell lines. Deleting the 119 bp promoter region surrounding the variants rs1004030 and rs1003049 by CRISPR-Cas9 genome editing resulted in reduced MMP14 expression in G415 cells. Electrophoretic mobility shift assay shows the presence of risk allele 'C'/'G' at rs1004030 and rs1003049 and create binding sites for transcription factors SOX10 and MYB, respectively. Further, stable knockdown of these transcription factors in G415 and TGBC1TKB cells showed reduced expression of MMP14. However, in both GBC cells, ectopic expression of these transcription factors increased the expression of MMP14. Rescue of MYB and SOX10 expression levels showed a significant increase in luciferase activity only in risk allele-carrying constructs. In conclusion, our study unveils a mechanistic role of the MMP14 promoter variants rs1004030 and rs1003049 in gallbladder cancer.

Genetic association of MMP14 promoter variants and their functional significance in gallbladder cancer pathogenesis.

Gallbladder cancer (GBC) is relatively rare but shows high frequency in certain geographical regions and ethnic groups, which include Northern and Eastern states of India. Previous studies in India have indicated the possible role of genetic predisposition in GBC pathogenesis. Although matrix metalloproteinase-14 (MMP14) is known modulator of tumour microenvironment and tumorigenesis and TCGA data also suggests its upregulation yet, its role in genetic predisposition for GBC is completely unknown. We explored MMP14 promoter genetic variants as risk factors and their implication in expression modulation and the pathogenesis of GBC. We genotyped all single nucleotide polymorphisms of MMP14 promoter by Sanger's sequencing in approximately 300 GBC and 300 control study subjects of Indian ethnicity and, in 26 GBC tissue samples. Protein expression of MMP14 in GBC tissue samples was checked by immunohistochemistry. In vitro luciferase reporter assay was carried out to elucidate role of promoter genetic variants on expression levels in two different cell lines. MMP14 promoter variants, rs1003349 (p value = 0.0008) and rs1004030 (p value = 0.0001) were significantly associated with GBC. Luciferase reporter assay showed high expression for risk alleles of both the SNPs. Genotype-phenotype correlation for rs1003349 and rs1004030, in patient sample, confirmed that risk allele carriers had higher expression levels of MMP14; moreover, the correlation pattern matched with genetic association models. Overall, this study unravels the association of MMP14 promoter SNPs with GBC which contribute to pathogenesis by increasing its expression.

A genome-wide resource for the analysis of protein localisation in Drosophila.

The Drosophila genome contains >13000 protein-coding genes, the majority of which remain poorly investigated. Important reasons include the lack of antibodies or reporter constructs to visualise these proteins. Here, we present a genome-wide fosmid library of 10000 GFP-tagged clones, comprising tagged genes and most of their regulatory information. For 880 tagged proteins, we created transgenic lines, and for a total of 207 lines, we assessed protein expression and localisation in ovaries, embryos, pupae or adults by stainings and live imaging approaches. Importantly, we visualised many proteins at endogenous expression levels and found a large fraction of them localising to subcellular compartments. By applying genetic complementation tests, we estimate that about two-thirds of the tagged proteins are functional. Moreover, these tagged proteins enable interaction proteomics from developing pupae and adult flies. Taken together, this resource will boost systematic analysis of protein expression and localisation in various cellular and developmental contexts.

Studies on interaction of insect repellent compounds with odorant binding receptor proteins by in silico molecular docking approach.

The aim of the study was to identify the interactions between insect repellent compounds and target olfactory proteins. Four compounds, camphor (C10H16O), carvacrol (C10H14O), oleic acid (C18H34O2) and firmotox (C22H28O5) were chosen as ligands. Seven olfactory proteins of insects with PDB IDs: 3K1E, 1QWV, 1TUJ, 1OOF, 2ERB, 3R1O and OBP1 were chosen for docking analysis. Patch dock was used and pymol for visualizing the structures. The interactions of these ligands with few odorant binding proteins showed binding energies. The ligand camphor had showed a binding energy of -136 kcal/mol with OBP1 protein. The ligand carvacrol interacted with 1QWV and 1TUJ proteins with a least binding energy of -117.45 kcal/mol and -21.78 kcal/mol respectively. The ligand oleic acid interacted with 1OOF, 2ERB, 3R1O and OBP1 with least binding energies. Ligand firmotox interacted with OBP1 and showed least binding energies. Three ligands (camphor, oleic acid and firmotox) had one, two, three interactions with a single protein OBP1 of Nilaparvatha lugens (Rice pest). From this in silico study we identified the interaction patterns for insect repellent compounds with the target insect odarant proteins. The results of our study revealed that the chosen ligands showed hydrogen bond interactions with the target olfactory receptor proteins.