Association of DFNA5, SYK, and NELL1 variants along with HPV infection in oral cancer among the prolonged tobacco-chewers

Human Papillomavirus-Attributable Head and Neck Cancers in India-A Systematic Review and Meta-Analysis

PURPOSE

Head and neck cancer accounts for about one third of the global burden in India. Mucosal high-risk human papillomavirus (HPV) has been hypothesized as a contributory risk factor for head and neck cancer (HNC) but its prevalence in Indian patients is not well established. Therefore, this systematic review and meta-analysis aimed to estimate the prevalence of HPV in HNC in India and their attributable fraction by considering the biomarkers of carcinogenesis, p16, and HPV E6/E7 mRNA.

METHODS

A systematic literature search was done in Medline via PubMed, Embase, Scopus, ScienceDirect, ProQuest, and Cochrane to identify studies on HPV and HNC in the Indian population, published between January 1990 and October 2022. Fifty-four eligible studies were identified and relevant clinical information was collected. Meta-analysis was conducted to estimate the pooled prevalence of HPV DNA, p16INK4a, and E6/E7 mRNA percent positivity by random-effect logistic regression model using Metapreg, STATA 18.

RESULTS

Thirty-four high-quality studies were taken for meta-analysis. The pooled prevalence of HPV in HNC was 20% (95% CI, 12 to 32) with a high level of heterogeneity (I2 = 90.79%). The proportion of HPV in oropharyngeal cancer (OPC; 22% [95% CI, 13 to 34]) and laryngeal cancer (LC; 29% [95% CI, 17 to 46]) was higher than in oral cancer (OC; 16% [95% CI, 8 to 30]). The HPV-attributable fraction of OPC, considering the E6/E7 mRNA and p16 positivity, was 12.54% and 9.68%, respectively, almost similar to LC (11.6% and 9.57%), while it was much lower in OC (3.36% and 4%).

CONCLUSION

The HPV-attributable fraction is considerably lower for OC, suggesting a negligible causative role of HPV in OC. A significant proportion of OPC and LC are attributed to HPV; however, their exact causative role is unclear because of the presence of other known risk factors.

Human Papillomavirus-Associated Oral Squamous Cell Carcinoma Among Adults Living in South-Central Asia: A Systematic Review

Human papillomavirus (HPV) related oral cancers are increasing and are associated with sexual risk behaviours. An increase in the incidence of oral cancer has been observed in South-central Asian countries. The objective was to systematically review the evidence on the association of HPV and oral squamous cell carcinoma (OSCC) among adults living in South-central Asia. We searched multiple databases and reference lists of relevant articles in December 2018. Quality assessment of the selected articles were done using the Newcastle-Ottawa quality assessment scale. Thirteen out of 150 articles met the eligibility criteria. Most studies were from India (10/13) followed by Pakistan (2/13) and Bangladesh (1/13). Half (7/13) of the studies found a positive association between HPV with OSCC. HPV 16, HPV 18 and HPV 16/18 were found to be the most common types implicated in HPV infection associated with OSCC. Moreover, buccal mucosa was the most common site of oral cancer. The review found equivocal evidence in relation to the association of HPV with oral squamous cell carcinoma among people living in South Asia.

In silico assessment of DNA damage response gene variants associated with head and neck cancer

Head and neck cancer (HNC), the sixth most common cancer globally, stands first in India, especially Northeast India, where tobacco usage is predominant, which introduces various carcinogens leading to malignancies by accumulating DNA damages. Consequently, the present work aimed to predict the impact of significant germline variants in DNA repair and Tumour Suppressor genes on HNC development. WES in Ion Proton^TM platform on 'discovery set' (n = 15), followed by recurrence assessment of the observed variants on 'confirmation set' (n = 40) using Sanger Sequencing was performed on the HNC-prevalent NE Indian populations. Initially, 53 variants were identified, of which seven HNC-linked DNA damage response gene variants were frequent in the studied populations. Different tools ascertained the biological consequences of these variants, of which the non-coding variants viz. EXO1_rs4150018, RAD52_rs6413436, CHD5_rs2746066, HACE1_rs6918700 showed risk, while FLT3_rs2491227 and BMPR1A_rs7074064 conferred protection against HNC by affecting transcriptional regulation and splicing mechanism. Molecular Dynamics Simulation of the full-length p53 model predicted that the observed coding TP53_rs1042522 variant conferred HNC-risk by altering the structural dynamics of the protein, which displayed difficulty in the transition between active and inactive conformations due to high-energy barrier. Subsequent pathway and gene ontology analysis revealed that EXO1, RAD52 and TP53 variants affected the Double-Strand Break Repair pathway, whereas CHD5 and HACE1 variants inactivated DNA repair cascade, facilitating uncontrolled cell proliferation, impaired apoptosis and malignant transformation. Conversely, FLT3 and BMPR1A variants protected against HNC by controlling tumorigenesis, which requires experimental validation. These findings may serve as prognostic markers for developing preventive measures against HNC.

The impact of prehistoric human dispersals on the presence of tobacco-related oral cancer in Northeast India

BACKGROUND

Northeast (NE) India is a subject of debate for predicting its involvement in prehistoric anatomically modern human (AMH) dispersal. The unique lifestyle and genetic characteristics of native ethnic groups in this region are believed to be responsible for their susceptibility to tobacco-related oral cancer (TrOC). The present study assessed mitochondrial macro-haplogroup (mHG) diversity and TrOC susceptibility autosomal loci to evaluate the impact of prehistoric AMH dispersal on the present day's high TrOC prevalence in major NE Indian ethnics.

METHODS

We considered 175 unrelated individuals from 35 ethnic groups and previously published 374 sequences for sequencing-based assessment of mtDNA-based marker by subsequent analyses like haplogroup diversity, phylogenetic, genetic structure by AMOVA, and MDS, descriptive statistics of demographic parameters, and migration analysis. Besides, we selected prolonged tobacco-chewing 124 case-control individuals from similar ethnic backgrounds for genotyping 115 autosomal loci in Sequenom iPLEX MassARRAY™ platform and mined 1000genome data (n = 398) for consequent global admixture and ancestry-specific allele frequencies-based analyses.

RESULTS

Our mtDNA-based findings suggested that NE populations were distinct from other Indian populations, owing to the first wave of migration from ancient southern China (∼54kya) and two successive spatial expansion events at ∼45kya and ∼43kya. Consequently, it probably acted as another source for prehistoric AMH dispersal in N/NE Asia. Besides, the second wave of back-migration from SE Asia (∼40kya) probably replaced the mitochondrial footprints of survivors from the first migrants and introduced the TrOC susceptibility traits in this region. Afterward, the autosomal marker-based observations on the transition of the disease-associated admixture component 'K6' from SE Asia reconfirmed these results. Moreover, we also observed that the mitochondrial mHG 'R' is significantly associated with the risk of TrOC (OR > 9.5) in NE India. Furthermore, the possible onset of the phenotypic expression of those traits was predicted at ∼4kya, thus, contributing to present-day's TrOC prevalence.

CONCLUSIONS

This study reflects its uniqueness by revealing an updated AMH dispersal route for the peopling in and out of NE India, which probably introduced the disease-causing traits in the ancestral NE Indian population. Those traits were then imprinted in their genome to get transferred through their respective generations, forming the present-day's TrOC-prevalent NE Indian population.

Whole exome sequencing identifies the potential role of genes involved in p53 pathway in Nasopharyngeal Carcinoma from Northeast India

Nasopharyngeal Carcinoma (NPC) found to be dependent on geographical and racial variation and is more prevalent in Northeast (NE) India. WES-based study was conducted in three states (tribes); Nagaland (Naga), Mizoram (Mizo) and Manipur (Manipuri), which provided an overview of germline variants involved inthemajor signaling pathways. Validation and recurrence assessment of WES data confirmed the risk effect of STEAP3_rs138941861 and JAG1_rs2273059, and the protective role of PARP4_rs17080653 and TGFBR1_rs11568778 variants, where STEAP3_rs138941861conferring Arg290His substitution was the only exonic non-synonymous variant and to be located in proximity to the linking region between the transmembrane and oxidoreductasedomainsof STEAP3 protein, andaffectedits structural and functional dynamics by altering the Electrostatic Potential around this connecting region. Moreover, these significantly associated variants having deleterious effect were observed to have interactions in p53 signaling pathway which emphasizes the importance of this pathway in the causation of NPC.

Prevalence of HSV, Varicella-Zoster, CMV, EBV and HPV in the oral cavity and the larynx carcinoma in Iran

Introduction: Viral diseases can have roles in oral cavity and larynx carcinoma. However, the relationship between HPV, herpetic infection and these cancers is not clear. Materials & methods: DNA of tissues from oral and larynx carcinoma was extracted and the presence of HPV, HSV-1, HSV-2, EBV, CMV and Varicella Zoster virus was detected. Results: We detected five HSV-1 in oral cavity cancer and two HSV-1 in larynx carcinoma. Also, four and two HPV-positive in oral cavity and larynx carcinoma were found, respectively. There were five HPV type 18 and one HPV type 31. None of our samples were infected with EBV, CMV, HSV-2 and Varicella Zoster virus. Conclusion: A higher prevalence of HPV and HSV-1 in cancerous tissues in comparison with normal ones was detected.

The Potential Roles of Extracellular Vesicles in Cigarette Smoke-Associated Diseases

Cigarette smoke contains more than 4,500 chemicals; most of which are highly reactive free radicals, which induce proinflammatory and carcinogenic reactions. Numerous efforts have focused extensively on the role of cigarette smoking as a cause of many diseases. Extracellular vesicles and exosomes have recently received increasing interest for their diagnostic and therapeutic roles in many diseases. However, research done on the role of extracellular vesicles and exosomes on cigarette smoke-induced chronic disease is still in its infancy. In this review, we summarize the recently addressed roles of extracellular vesicles and exosomes in the pathogenesis of cigarette smoke-related diseases, such as chronic obstructive pulmonary disease, cardiovascular disease, lung cancer, and oral cancer. Moreover, their potential utilization and future prospects as diagnostic biomarkers for cigarette smoke-related diseases are described.