Early Detection of Oral Squamous Cell Carcinoma (OSCC) - Role of Genetics: A Literature Review

Distinct cellular composition between normal surgical margins and tumor tissues in oral squamous cell carcinoma

BACKGROUND

Adequate resection of normal surgical margins is important. However, the clear distinction between the normal surgical margins and tumor tissues is still difficult.

OBJECTIVE

Here, this study analyzed the variety of cell types in tumors and the normal surgical margins using a computational approach.

METHODS

The composition of cell types was compared between the two tissues by statistical and machine learning approaches.

RESULTS

The results showed the distinct cellular composition between tumor-adjacent and tumor tissues. In particular, endothelial cells were highly represented and macrophages were underrepresented at the normal surgical margin. Moreover, the normal surgical margin and tumor tissues could be discriminated using a machine learning algorithm.

CONCLUSION

The results will help to understand cellular differences between normal surgical margins and tumor tissues and to provide potentials for tumor detection and treatment.

Negative regulation of miR-1288-3p/KRT4 axis through a circular RNA in oral cancer

Circular RNA (circRNA) has been widely reported to be involved in oral squamous cell carcinoma (OSCC), while the way in which hsa_circ_0096042 affects OSCC remains unclear. The hsa_circ_0096042, miR-1288-3p, and KRT4 expression in OSCC tissues and cell lines were detected by quantitative reverse-transcription polymerase chain reaction. Based on the overexpression of hsa_circ_0096042, miR-1288-3p, or KRT4, the viability and proliferation of OSCC cells were analyzed by cell counting kit-8 and colony formation assay, and the protein levels of Bax and Bcl-2 were detected by western blot, and the growth of cancer cells in vivo was analyzed by xenograft experiment. In addition, the database was used to predict the binding of hsa_circ_0096042, miR-1288-3p, and KRT4, and the interaction was confirmed by luciferase, RIP, and RNA pull-down assay. Hsa_circ_0096042 and KRT4 were abnormally downregulated and miR-1288-3p was upregulated in OSCC. Hsa_circ_0096042 overexpression restrained the proliferation and viability of OSCC cells, facilitated apoptosis, and inhibited the growth of cancer cells in vivo. Hsa_circ_0096042 bound to miR-1288-3p, whose upregulation promoted OSCC progression and eliminated the effects of overexpression of hsa_circ_0096042 on OSCC cells. KRT4 was the target gene for miR-1288-3p. Hsa_circ_0096042 plays an antitumor role in OSCC via miR-1288-3p/KRT4 axis.

Comparative Evaluation of Immunohistochemical Expression of p16 with p16 Microsatellite Marker by PCR in Surgical Margins of Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is most common oral cancer with multifactorial etiology. Surgical therapy is treatment of choice but known to have recurrence. The main reason for recurrence is associated with surgical margins which need to be tumor free. Changes at genetic level cannot be ascertained only through routine light microscopy in surgical margins, even though they are tumor free. Detection of early marker like p16 can help in predicting the risk of recurrence. Hence study aimed to detect p16 microsatellite marker (D9s1747) in surgical margins of oral squamous cell carcinoma and compare the same with p16 marker through immunohistochemistry. Total of 40 paraffin embedded tissue samples diagnosed and surgically treated cases of OSCC were included. From each sample one tumor proper and one surgical margin was obtained. From paraffin embedded tissue sample 2 sections of 4 µm thick was obtained from tumor proper and tumor margin. One section was stained with hematoxylin and eosin and other section was stained immunohistochemically using p16 antibody. DNA extraction was done for tumor proper and surgical margin tissue and PCR analysis was carried for p16 microsatellite marker (D91747). Out of 40 cases 37 cases showed positivity in tumor proper for p16 with IHC. Out of 37 cases 23 cases showed positivity for both tumor proper and surgical margin. There were 3 cases negative for tumor proper. Out of these 3 cases, 1 (33.3%) case was positive for surgical margin. Out of 40 cases 27 cases showed positivity for tumor proper with p16 microsatellite marker. Out of 27 cases 16 cases showed positivity for both tumor proper and surgical margin. There were 13 cases negative for tumor proper. However there were 8 (61.5%) cases negative which were in tumor proper but showed positivity for surgical margin. Other 5 cases were negative in both tumor proper and surgical margin. Our study reveals that surgical margins of OSCC exhibit alteration in p16 markers both by IHC and PCR techniques. p16 and p16 microsatellite marker detection in margins indicates field change. Further studies with larger sample size comparing expression with clinical and histological parameter and follow up has to be done to substantiate our findings.

Detection and comparison of microsatellite marker D9S1747 with clinical stages and grades of oral squamous cell carcinoma

Background:

One of the main characteristics of oral squamous cell carcinoma (OSCC) is genetic alteration in specific target regions. Allelic imbalance in tumor suppressor genes is the key event in OSCC which is associated with loss of heterozygosity mostly on chromosome 9p21 locus which includes p16 marker. p16 (D9S1747) is a microsatellite marker which detects early changes in OSCC. To redefine more clearly the role of D9S1747 (p16 microsatellite marker) and its expression in OSCC, the study was designed with the aim to check the detection of D9S1747 in OSCC and to compare the same with histopathological grades and tumor node metastasis staging.

Materials and Methods:

Forty cases of paraffin-embedded tissue section which was histologically confirmed as OSCC and 10 cases of normal tissues were retrieved from the archives. DNA was extracted from the tissue sections and subjected for polymerase chain reaction to detect p16 microsatellite marker D9S1747. Data were analyzed using Chi-square test and Fisher's exact test.

Results:

Twenty-seven cases (67.5%) showed p16 microsatellite marker positivity for OSCC. It was observed that 44.4%, 51.9% and 3.7% p16 microsatellite markers were positive in Stage 1, Stage 2 and Stage 4 OSCC cases, respectively. p16 microsatellite marker positivity was found in 77.8%, 22.2% and 0% for well-differentiated, moderately differentiated and poorly differentiated OSCC cases, respectively.

Conclusion:

The observations of the present study revealed D9S1747 marker as an early event in OSCC, and this can be used as a prognostic marker.

Paracoccidioidomycosis mimicking squamous cell carcinoma on the dorsum of the tongue and review of published literature

INTRODUCTION

Paracoccidioidomycosis is a disease that is endemic to southern and southeastern Brazil, caused by the fungus Paracoccidioides brasiliensis. The most common clinical oral manifestation is the presence of multiple granulomatous ulcers with hemorrhagic dots, located mainly on the lips, palate, and buccal mucosa. However, the disease can manifest atypically as a single ulcer, mimicking oral squamous cell carcinoma (SCC) or tuberculosis.

CASE REPORT

A 65-year-old male patient presented with a complaint of a single ulcerated lesion on the dorsum of the tongue; the lesion had evolved over 6 months. The diagnostic hypotheses were SCC and oral manifestation of tuberculosis. An incisional biopsy was performed, and histopathological analysis of the specimen revealed pseudoepitheliomatous hyperplasia, a granulomatous structure of epithelioid histiocytes, multinucleated giant cells, and lymphocytes in the connective tissue. Grocott staining confirmed the presence of the fungus in the lesion, and a diagnosis was made of paracoccidioidomycosis. The patient was treated with 200 mg/day of itraconazole for 12 months and now shows no signs or symptoms of recurrence of the disease.

CONCLUSION

Correct diagnosis is essential for a successful therapeutic approach and resolution of the lesion.