BackgroundGingivo-buccal squamous cell carcinoma (GBSCC) is one of the most common oral cavity cancers in India with less than 50% patients surviving past 5 years. Here, we report a whole transcriptome profile on a batch of GBSCC tumours with diverse tobacco usage habits. The study provides an entire landscape of altered expression with an emphasis on searching for targets with therapeutic potential.MethodsWhole transcriptomes of 12 GBSCC tumours and adjacent normal tissues were sequenced and analysed to explore differential expression of genes. Expression changes were further compared with those in TCGA head and neck cohort (n = 263) data base and validated in an independent set of 10GBSCC samples.ResultsDifferentially expressed genes (n = 2176) were used to cluster the patients based on their tobacco habits, resulting in 3 subgroups. Immune response was observed to be significantly aberrant, along with cell adhesion and lipid metabolism processes. Different modes of immune evasion were seen across 12 tumours with up-regulation or consistent expression of CD47, unlike other immune evasion genes such as PDL1, FUT4, CTLA4 and BTLA which were downregulated in a few samples. Variation in infiltrating immune cell signatures across tumours also indicates heterogeneity in immune evasion strategies. A few actionable genes such as ITGA4, TGFB1 and PTGS1/COX1 were over expressed in most samples.ConclusionThis study found expression deregulation of key immune evasion genes, such as CD47 and PDL1, and reasserts their potential as effective immunotherapeutic targets for GBSCC, which requires further clinical studies. Present findings reiterate the idea of using transcriptome profiling to guide precision therapeutic strategies.

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Oral cancer generally progresses from precancerous lesions such as leukoplakia (LK), lichen planus (LP) and oral submucous fibrosis (OSMF). Since few of these precancers progress to cancers; it is worth to identify biological molecules that may play important roles in progression. Here, expression deregulation of 7 miRNAs (mir204, mir31, mir31*, mir133a, mir7, mir206 and mir1293) and their possible target genes in 23 cancers, 18 LK, 12 LP, 23 OSMF tissues compared to 20 healthy tissues was determined by qPCR method. Expression of mir7, mir31, mir31* and mir1293 was upregulated and that of mir133a, mir204 and mir206 was downregulated in cancer. Expression of most of these miRNAs was also upregulated in LK and LP tissues but not in OSMF. Expression deregulation of some of the target genes was also determined in cancer, LK and LP tissues. Significant upregulation of mir31 and downregulation of its target gene, CXCL12, in cancer, LK and LP tissues suggest their importance in progression of precancer to cancer. Expression upregulation of mir31 was also validated using GEO data sets. Although sample size is low, novelty of this work lies in studying expression deregulation of miRNAs and target genes in oral cancer and three types of precancerous lesions.

Familial spontaneous pneumothorax is one of the phenotypes of Birt-Hogg-Dubé syndrome (BHDS), an autosomal dominant condition associated with folliculin (FLCN). We investigated clinical and genetic data of an Indian family having two patients suffering from spontaneous pneumothorax in the absence of skin lesions or renal tumors. HRCT scan of patient's lung revealed paracardiac cysts, and DNA sequencing of all 14 exons of FLCN from patients showed the presence of heterozygous "C allele" deletion in the poly-cytosine (poly-C) tract of exon 11 leading to truncated folliculin. This mutation was also observed in four asymptomatic members of the family. Our results confirmed the presence of deletion mutation in poly-C tract of FLCN in members of BHDS family. This is the first report of genetic insight in a BHDS family from India but in-depth studies with a larger sample set are necessary to understand mechanism of familial pneumothorax.

BackgroundMicroRNAs have been implicated in cancer but studies on their role in precancer, such as leukoplakia, are limited. Sequence variations at eight miRNA and four miRNA processing genes were studied in 452 healthy controls and 299 leukoplakia patients to estimate risk of disease.ResultsGenotyping by TaqMan assay followed by statistical analyses showed that variant genotypes at Gemin3 and mir-34b reduced risk of disease [OR = 0.5(0.3–0.9) and OR = 0.7(0.5–0.9) respectively] in overall patients as well as in smokers [OR = 0.58(0.3–1) and OR = 0.68(0.5–0.9) respectively]. Among chewers, only mir29a significantly increased risk of disease [OR = 1.8(1–3)]. Gene-environment interactions using MDR-pt program revealed that mir29a, mir34b, mir423 and Xpo5 modulated risk of disease (p < 0.002) which may be related to change in expression of these genes as observed by Real-Time PCR assays. But association between polymorphisms and gene expressions was not found in our sample set as well as in larger datasets from open access platforms like Genevar and 1000 Genome database.ConclusionVariations in microRNAs and their processing genes modulated risk of precancer but further in-depth study is needed to understand mechanism of disease process.