Analysis of methylation and mRNA expression status of FADD and FAS genes in patients with oral squamous cell carcinoma

Impaired FADD/BID signaling mediates cross-resistance to immunotherapy in Multiple Myeloma

The treatment landscape in multiple myeloma (MM) is shifting from genotoxic drugs to immunotherapies. Monoclonal antibodies, immunoconjugates, T-cell engaging antibodies and CART cells have been incorporated into routine treatment algorithms, resulting in improved response rates. Nevertheless, patients continue to relapse and the underlying mechanisms of resistance remain poorly understood. While Impaired death receptor signaling has been reported to mediate resistance to CART in acute lymphoblastic leukemia, this mechanism yet remains to be elucidated in context of novel immunotherapies for MM. Here, we describe impaired death receptor signaling as a novel mechanism of resistance to T-cell mediated immunotherapies in MM. This resistance seems exclusive to novel immunotherapies while sensitivity to conventional anti-tumor therapies being preserved in vitro. As a proof of concept, we present a confirmatory clinical case indicating that the FADD/BID axis is required for meaningful responses to novel immunotherapies thus we report impaired death receptor signaling as a novel resistance mechanism to T-cell mediated immunotherapy in MM.

The diagnostic or prognostic values of FADD in cancers based on pan‑cancer analysis

Previous studies have determined that aberrant expression of the fas-associated death domain (FADD) contributes to the development of cancer. However, no pan-cancer analysis has been reported to explore the relationship between FADD and various cancers. Multiple databases were screened to identify cancer datasets for the present study and to validate the expression of FADD in various tumors. The association of FADD alteration with cancer prognosis, clinical features and tumor immunity was also evaluated. Reverse transcription-quantitative PCR (RT-qPCR) was utilized to confirm the expression of FADD in breast, colon, liver and gastric cancer cells. Analysis of Gene Expression Omnibus database and The Cancer Genome Atlas database indicated that FADD was highly expressed in breast invasive carcinoma (BRCA), cervical squamous cell carcinoma and endocervical adenocarcinoma, cholangiocarcinoma, colon adenocarcinoma (COAD), esophageal carcinoma (ESCA), kidney renal clear cell carcinoma, kidney renal papillary cell carcinoma, liver hepatocellular carcinoma (LIHC), lung adenocarcinoma (LUAD) and prostate adenocarcinoma, whereas RT-qPCR results revealed that FADD was highly expressed in breast cancer and colon cancer. Further analyses demonstrated that FADD expression was significantly altered in ESCA, head and neck squamous cell carcinoma (HNSC), lung squamous cell carcinoma and BRCA. FADD expression was observed to be a risk factor of the overall survival in patients with HNSC, LIHC and LUAD as demonstrated by Kaplan-Meier and Cox regression analyses. The results of the present study demonstrated that FADD is highly expressed in numerous malignancies and can be utilized as a biomarker for the diagnosis of BRCA, COAD, LIHC and stomach adenocarcinoma. Moreover, FADD expression is a predictive risk factor for the development of HNSC, LIHC and LUAD and can potentially be used as a prognostic marker for these cancers.

Proteomic and phosphoproteomic profiling of shammah induced signaling in oral keratinocytes

Shammah is a smokeless tobacco product often mixed with lime, ash, black pepper and flavorings. Exposure to shammah has been linked with dental diseases and oral squamous cell carcinoma. There is limited literature on the prevalence of shammah and its role in pathobiology of oral cancer. In this study, we developed a cellular model to understand the effect of chronic shammah exposure on oral keratinocytes. Chronic exposure to shammah resulted in increased proliferation and invasiveness of non-transformed oral keratinocytes. Quantitative proteomics of shammah treated cells compared to untreated cells led to quantification of 4712 proteins of which 402 were found to be significantly altered. In addition, phosphoproteomics analysis of shammah treated cells compared to untreated revealed hyperphosphorylation of 36 proteins and hypophosphorylation of 83 proteins (twofold, p-value ≤ 0.05). Bioinformatics analysis of significantly altered proteins showed enrichment of proteins involved in extracellular matrix interactions, necroptosis and peroxisome mediated fatty acid oxidation. Kinase-Substrate Enrichment Analysis showed significant increase in activity of kinases such as ROCK1, RAF1, PRKCE and HIPK2 in shammah treated cells. These results provide better understanding of how shammah transforms non-neoplastic cells and warrants additional studies that may assist in improved early diagnosis and treatment of shammah induced oral cancer.

Methylation as a critical epigenetic process during tumor progressions among Iranian population: an overview

Cancer is one of the main health challenges and leading causes of deaths in the world. Various environmental and genetic risk factors are associated with tumorigenesis. Epigenetic deregulations are also important risk factors during tumor progression which are reversible transcriptional alterations without any genomic changes. Various mechanisms are involved in epigenetic regulations such as DNA methylation, chromatin modifications, and noncoding RNAs. Cancer incidence and mortality have a growing trend during last decades among Iranian population which are significantly related to the late diagnosis. Therefore, it is required to prepare efficient molecular diagnostic panels for the early detection of cancer in this population. Promoter hyper methylation is frequently observed as an inhibitory molecular mechanism in various genes associated with DNA repair, cell cycle regulation, and apoptosis during tumor progression. Since aberrant promoter methylations have critical roles in early stages of neoplastic transformations, in present review we have summarized all of the aberrant methylations which have been reported during tumor progression among Iranian cancer patients. Aberrant promoter methylations are targetable and prepare novel therapeutic options for the personalized medicine in cancer patients. This review paves the way to introduce a non-invasive methylation specific panel of diagnostic markers for the early detection of cancer among Iranians.

Promoter Hypermethylation of LATS1 Gene in Oral Squamous Cell Carcinoma (OSCC) among North Indian Population

BACKGROUND

LATS1 (Large Tumor Suppressor, isoform 1) is a gene that forms a complex with the cyclin-dependent kinase, CDK1, and regulates cell cycle progression. Genetic modifications lead to a loss in the activity of LATS1 gene. OSCC is the most commonly emerging cancer caused by genetic as well as epigenetic changes. Epigenetics changes vary from one population to another because these are influenced by dietary factors and environmental factors.  Tobacco chewing and smoking has been reported as major risk factors in OSCC. No report was found in the previous literature showing promoter hypermethylation of LATS1 gene.

METHODS

A total of 50 OSCC patients and 20 normal individuals were recruited in this study. Blood samples (50) from OSCC patients and blood samples (20) from healthy individuals as controls were used in the present study. Isolation of genomic DNA was carried out from blood using the standard phenol-chloroform extraction. Further Isolated DNA was modified with sodium bisulfite using the agarose bead method and finally, the methylation studies of LATS1 gene were carried out using Methylation-Specific PCR (MSP-PCR).

RESULTS

19 out of 50 patients (38.0%) were found to be methylated for LATS1 gene.; a statistically significant result was obtained (p -value= < 0.05) with an odds ratio of 0.37 in cases compared to controls. The status of methylation of LATS1 genes was also found to be statistically significantly associated with smokers and tobacco chewers (p-value = < 0.05). The methylation of LATS1 gene showed a significant risk of developing OSCC in patients.

CONCLUSION

These results suggest that the LATS1 gene may provide a better alternative as a diagnostic biomarker. This is the first report on the promoter hypermethylation of LATS1 gene in OSCC patients among the North Indian population.<br />.

Promoter Hypermethylation of LATS2 Gene in Oral Squamous Cell Carcinoma (OSCC) Among North Indian Population

Large Tumor Suppressor (LATS2) gene are Tumor Suppressor gene, linked with epigenetic modifications. LATS2 promoter hypermethylation is an important epigenetic silencing mechanism leading to cancer. Cancer is the most common, vicious and dangerously increasing diseases of the world today, associated with high morbidity and mortality. Oral cancers (OC) are the blazing universal dilemma and is the sixth most frequent cancer observed in Indian population. Tobacco consumption is the main cause of the increase in OSCC. The association between LATS2 in the pathogenesis of cancers propose that their combination might be studied as a possible molecular marker for particular subgroups of patients. Therefore, the present study tried to investigate whether LATS2 promoter methylation was associated with oral squamous cell carcinoma (OSCC) in North Indian subjects. DNA methylation quantitative studies of LATS2 Tumor Suppressor genes were performed by methylation-specific polymerase chain reaction (MSP). 38 out of 70 patients (55 %) were found to be methylated for LATS2 gene, a statistically significant result was obtained (p-value < 0.005) for LATS2 genes. The results suggest that epigenetic changes may be related to the down-regulation of LATS2 expression. It can be concluded that LATS2 gene plays a significant role in the diagnosis of cancer and provide a better alternative as a diagnostic biomarker. Our data infer that a low LATS2 expression due to methylation may contribute to the cancer progression and could be useful for the diagnosis of OSCC. Therefore, investigation of promoter methylation in such genes may provide a biomarker which may prove to be useful in early detection of Oral Cancer.

FADD in Cancer: Mechanisms of Altered Expression and Function, and Clinical Implications

FADD was initially described as an adaptor molecule for death receptor-mediated apoptosis, but subsequently it has been implicated in nonapoptotic cellular processes such as proliferation and cell cycle control. During the last decade, FADD has been shown to play a pivotal role in most of the signalosome complexes, such as the necroptosome and the inflammasome. Interestingly, various mechanisms involved in regulating FADD functions have been identified, essentially posttranslational modifications and secretion. All these aspects have been thoroughly addressed in previous reviews. However, FADD implication in cancer is complex, due to pleiotropic effects. It has been reported either as anti- or protumorigenic, depending on the cell type. Regulation of FADD expression in cancer is a complex issue since both overexpression and downregulation have been reported, but the mechanisms underlying such alterations have not been fully unveiled. Posttranslational modifications also constitute a relevant mechanism controlling FADD levels and functions in tumor cells. In this review, we aim to provide detailed, updated information on alterations leading to changes in FADD expression and function in cancer. The participation of FADD in various biological processes is recapitulated, with a mention of interesting novel functions recently proposed for FADD, such as regulation of gene expression and control of metabolic pathways. Finally, we gather all the available evidence regarding the clinical implications of FADD alterations in cancer, especially as it has been proposed as a potential biomarker with prognostic value.

Epigenetic inactivation of tumour suppressor coding and non-coding genes in human cancer: an update

Cancer cells undergo many different alterations during their transformation, including genetic and epigenetic events. The controlled division of healthy cells can be impaired through the downregulation of tumour suppressor genes. Here, we provide an update of the mechanisms in which epigenetically altered coding and non-coding tumour suppressor genes are implicated. We will highlight the importance of epigenetics in the different molecular pathways that lead to enhanced and unlimited capacity of division, genomic instability, metabolic shift, acquisition of mesenchymal features that lead to metastasis, and tumour plasticity. We will briefly describe these pathways, focusing especially on genes whose epigenetic inactivation through DNA methylation has been recently described, as well as on those that are well established as being epigenetically silenced in cancer. A brief perspective of current clinical therapeutic approaches that can revert epigenetic inactivation of non-coding tumour suppressor genes will also be given.

Contribution of LATS1 and LATS2 promoter methylation in OSCC development

The aberrant DNA methylation of the tumor suppressor genes involved in DNA Damage Response (DDR) signaling and cell cycle regulation may lead to the tumorigenesis. Our purpose here is to analyze the promoter methylation and mRNA expression levels of LATS1 and LATS2 (LATS1/2) genes in OSCC. Promoter methylation status of LATS1/2 genes was evaluated in 70 OSCC paraffin-embedded tissues and 70 normal oral samples, using Methylation Specific PCR (MSP). LATS1/2 mRNA expression profiles were also investigated in 14 OSCC patients and 14 normal samples, using real-time PCR. In both candidate genes, promoter methylation assessment revealed significant relationship between cases and controls (OR = 2.24, 95 % CI = 1.40-3.54, P = 0.001; LATS1 and OR = 15.5, 95%CI = 3.64-64.76, P < 0.001; LATS2). As well as, the evaluation of mRNA expression levels showed decreased expression in OSCC tissues in compare to control tissues. (Mean ± SD 1.74 ± 0.14 in OSCC versus 2.10 ± 0.24 in controls, P < 0.001; LATS1 and Mean ± SD 1.36 ± 0.077 in OSCC versus 1.96 ± 0.096 in controls, P < 0.001; LATS2). To the best our knowledge, this is the first report regarding the down-regulation of LATS1/2 through promoter methylation in OSCC. It is suggested to explore the down-stream transcription factors of both genes for finding the molecular mechanism of this deregulation in OSCC.

Knocking down of p53 triggers apoptosis and autophagy, concomitantly with inhibition of migration on SSC-4 oral squamous carcinoma cells

Oral squamous cell carcinoma (OSCC) is a malignancy with elevated prevalence and somber prognosis due to the fact that most of the patients are diagnosed at an advanced stage. p53 has a crucial role in proliferation and apoptosis during the occurrence and development of numerous malignant tumors. The impact of mutated p53 on the development and progression of OSCC is unclear and might have therapeutic implications. Using an in vitro RNA interference experiment, we have evaluated the impact of p53 knockdown on cell viability, apoptosis, migration, and gene expression for key genes involved in apoptosis and angiogenesis. We observed that inhibiting the expression of p53 decreased the proliferation ability and induced apoptosis/autophagy in SSC-4 cells. Moreover, we observed that this has decreased migration and has blocked the expression of VEGF. In conclusion, our research provides a proof that a direct connection between p53 knockdown and OSCC cell death can be established, therefore opening new potential directions in OSCC molecular therapeutics and management.