Detection of human papillomavirus infection in oral cancers reported at dental facility: assessing the utility of FFPE tissues.

Incidence of human papillomavirus (HPV)-associated oral cancers is on the rise. However, epidemiological data of this subset of cancers are limited. Dental hospital poses a unique advantage in detection of HPV-positive oral malignancies. We assessed the utility of formalin-fixed paraffin-embedded (FFPE) tissues, which are readily available, for evaluation of high-risk HPV infection in oral cancer. For protocol standardization, we used 20 prospectively collected paired FFPE and fresh tissues of histopathologically confirmed oral cancer cases reported in Oral Medicine department of a dental hospital for comparative study. Only short PCRs (~ 200 bp) of DNA isolated using a modified xylene-free method displayed a concordant HPV result. For HPV analysis, we used additional 30 retrospectively collected FFPE tissues. DNA isolated from these specimens showed an overall 23.4% (11/47) HPV positivity with detection of HPV18. Comparison of HPV positivity from dental hospital FFPE specimens with overall HPV positivity of freshly collected oral cancer specimens (n = 55) from three cancer care hospitals of the same region showed notable difference (12.7%; 7/55). Further, cancer hospital specimens showed HPV16 positivity and displayed a characteristic difference in reported sub-sites and patient spectrum. Overall, using a xylene-free FFPE DNA isolation method clubbed with short amplicon PCR, we showed detection of HPV-positive oral cancer in dental hospitals.

Characterization of key transcription factors as molecular signatures of HPV-positive and HPV-negative oral cancers.

Prior studies established constitutively active AP-1, NF-κB, and STAT3 signaling in oral cancer. Differential expression/activation of specific members of these transcription factors has been documented in HPV-positive oral lesions that respond better to therapy. We performed a comprehensive analysis of differentially expressed, transcriptionally active members of these pivotal signaling mediators to develop specific signatures of HPV-positive and HPV-negative oral lesions by immunohistochemical method that is applicable in low-resource settings. We examined a total of 31 prospective and 30 formalin-fixed, paraffin-embedded tissues from treatment-naïve, histopathologically and clinically confirmed cases diagnosed as oral or oropharyngeal squamous cell carcinoma (OSCC/OPSCC). Following determination of their HPV status by GP5 + /GP6 +  PCR, the sequential sections of the tissues were evaluated for expression of JunB, JunD, c-Fos, p50, p65, STAT3, and pSTAT3(Y705), along with two key regulatory proteins pEGFR and p16 by IHC. Independent analysis of JunB and p65 showed direct correlation with HPV positivity, whereas STAT3 and pSTAT3 were inversely correlated. A combined analysis of transcription factors revealed a more restrictive combination, characterized by the presence of AP-1 and NF-κB lacking involvement of STAT3 that strongly correlated with HPV-positive tumors. Presence of STAT3/pSTAT3 with NF-κB irrespective of the presence or absence of AP-1 members was present in HPV-negative lesions. Expression of pSTAT3 strongly correlated with all the AP-1/NF-κB members (except JunD), its upstream activator pEGFRY1092 , and HPV infection-related negative regulator p16. Overall, we show a simple combination of AP-1, NF-κB, and STAT3 members' expression that may serve as molecular signature of HPV-positive lesions or more broadly the tumors that show better prognosis.

Short-term acute effects of gutkha chewing on heart rate variability among young adults: A cross-sectional study.

BACKGROUND AND OBJECTIVES: An increase in the consumption of smokeless tobacco has been noticed among high school, college students, and adults. Despite the antiquity and popularity of chewing tobacco in India, its effects have not been investigated systematically in humans. The aim of this study was to investigate acute effects of gutkha chewing on heart rate variability (HRV) among healthy young adults. MATERIALS AND METHODS: A total of 60 young adult males were included in the study. Each individual was asked to chew tobacco and subjected to HRV analysis. HRV analysis using short-term electrocardiogram recording was used to measure HRV parameters before gutkha chewing and at 5, 15, and 30 min after chewing tobacco. One-way analysis of variance and paired t-test was used to assess changes over time. RESULTS: There was a significant increase in heart rate (HR) during tobacco chewing. Mean HR at baseline measured 73.0 ± 6.2 bpm. There was a rise in mean HR to 83.7 ± 9.1 bpm at 5 min during tobacco chewing and gradual reduction to baseline observed after 15 min followed by no significant change till 30 min. The normalized low-frequency power and LF/high-frequency (HF) power ratio were elevated after 5 min; however, normalized HF power was reduced after 5 min tobacco chewing. CONCLUSION: Gutkha is closely associated with traditional cardiovascular risk factors as detected by a transient enhancing sympathetic activity during tobacco chewing in the form of increased HRV parameters or an imbalance between sympathetic and parasympathetic neural activity among healthy young adults.