The utility of evaluating mismatch repair proteins in endometrial carcinoma: an experience from a tertiary referral centre in North India.

BACKGROUND: Endometrial cancer (EC) is a common gynecological malignancy. Around 25-30% patients have mismatch repair deficiency (MMRd). Lynch syndrome is caused by germline mutations in MMR genes. Lynch-associated tumours have better prognosis, however implications for prognosis and survival is less known. Microsatellite insufficiency (MSI) is associated with high neoantigen loads and number of tumor infiltrating lymphocytes, which overexpresses PD-1 and PD-L1 and are excellent candidates for PD-1-targeted immunotherapies. In this study, we aim to evaluate the utility of MMR in patients with EC and its clinico-pathological correlation. METHODS: Eighty-two cases of EC which underwent MMR evaluation over a period of five years at our centre were included. Demographics, clinical details including family history, histopathological and immunohistochemical (IHC) parameters were recorded. Tumors with loss-of at least one protein were considered MMR deficient (MMRd) and those with intact expression were MMR proficient (MMRp). RESULTS: Of 82 cases tested, 27 (33%) were MMRd. Frequencies of IHC MMR loss of expression were: MLH1/PMS2: 17 (21%), MSH6 loss only: 3 (4%), MSH2/MSH6 loss: 3 (4%), PMS2 loss: 2 (2%). In MMRd cases, most common histologic tumor type was endometrioid adenocarcinoma (70%). Loss of expression was significantly (p < 0.001) more frequent in lower uterine segment involvement and positive family history. CONCLUSIONS: MSI plays an important role in the progression of endometrial cancer. Lower uterine segment involvement and positive family history are significant predictor of MMR loss. Routine testing of MMR proteins in endometrial cancer can contribute to screening of Lynch syndrome families and make immunotherapy available as a treatment option.

Gene expression profiling of peripheral blood mononuclear cells in the setting of peripheral arterial disease.

BACKGROUND: Peripheral arterial disease (PAD) is a relatively common manifestation of systemic atherosclerosis that leads to progressive narrowing of the lumen of leg arteries. Circulating monocytes are in contact with the arterial wall and can serve as reporters of vascular pathology in the setting of PAD. We performed gene expression analysis of peripheral blood mononuclear cells (PBMC) in patients with PAD and controls without PAD to identify differentially regulated genes. METHODS: PAD was defined as an ankle brachial index (ABI) ≤0.9 (n = 19) while age and gender matched controls had an ABI > 1.0 (n = 18). Microarray analysis was performed using Affymetrix HG-U133 plus 2.0 gene chips and analyzed using GeneSpring GX 11.0. Gene expression data was normalized using Robust Multichip Analysis (RMA) normalization method, differential expression was defined as a fold change ≥1.5, followed by unpaired Mann-Whitney test (P < 0.05) and correction for multiple testing by Benjamini and Hochberg False Discovery Rate. Meta-analysis of differentially expressed genes was performed using an integrated bioinformatics pipeline with tools for enrichment analysis using Gene Ontology (GO) terms, pathway analysis using Kyoto Encyclopedia of Genes and Genomes (KEGG), molecular event enrichment using Reactome annotations and network analysis using Ingenuity Pathway Analysis suite. Extensive biocuration was also performed to understand the functional context of genes. RESULTS: We identified 87 genes differentially expressed in the setting of PAD; 40 genes were upregulated and 47 genes were downregulated. We employed an integrated bioinformatics pipeline coupled with literature curation to characterize the functional coherence of differentially regulated genes. CONCLUSION: Notably, upregulated genes mediate immune response, inflammation, apoptosis, stress response, phosphorylation, hemostasis, platelet activation and platelet aggregation. Downregulated genes included several genes from the zinc finger family that are involved in transcriptional regulation. These results provide insights into molecular mechanisms relevant to the pathophysiology of PAD.