Prognostic value of the PIK3CA, AKT, and PTEN mutations in oral squamous cell carcinoma: literature review

LC-Orbitrap HRMS-Based Proteomics Reveals Novel Mitochondrial Dynamics Regulatory Proteins Associated with RasV12-Induced Glioblastoma (GBM) of Drosophila

Glioblastoma multiforme (GBM) is the most prevalent and aggressive brain tumor found in adult humans with a poor prognosis and average survival of 14-15 months. In order to have a comprehensive understanding of proteome and identify novel therapeutic targets, this study focused mainly on the differentially abundant proteins (DAPs) of RasV12-induced GBM. RasV12 is a constitutively active Ras mutant form essential for tumor progression by continuously activating signaling pathways leading to uncontrolled tumor growth. This study used a transgenic Drosophila model with RasV12 overexpression using the repo-GAL4 driver line, specifically in glial cells, to study GBM. The high-resolution mass spectrometry (HRMS)-based proteomic analysis of the GBM larval central nervous system identified three novel DAPs specific to mitochondria. These DAPs, probable maleylacetoacetate isomerase 2 (Q9VHD2), bifunctional methylene tetrahydrofolate dehydrogenase (Q04448), and glutamine synthetase1 (P20477), identified through HRMS were further validated by qRT-PCR. The protein-protein interaction analysis revealed interactions between RasV12 and DAPs, with functional links to mitochondrial dynamics regulators such as Drp1, Marf, Parkin, and HtrA2. Notably, altered expressions of Q9VHD2, P20477, and Q04448 were observed during GBM progression, which offers new insights into the involvement of mitochondrial dynamic regulators in RasV12-induced GBM pathophysiology.

Decoding PTEN: from biological functions to signaling pathways in tumors

The tumor suppressor gene Phosphatase and tensin homologue deleted on chromosome 10 (PTEN), possessing both protein and lipid phosphatase activities, is frequently mutated in various human cancers. PTEN aberrations disrupt critical cellular processes like proliferation, apoptosis, migration, and invasion, thereby promoting tumor growth. In the cells, PTEN localizes to the nucleus, cytoplasm, or cell membrane, and its roles depends on the subcellular localization. PTEN is regulated at the transcriptional, post-transcriptional, and post-translational levels, implying that its functions on the tumors are complex. The relationship between PTEN abnormalities and tumors has garnered significant interest in recent years. PTEN regulates essential cellular processes involved in tumorigenesis. Mutations or deletions in the PTEN gene often correlate with unfavorable prognosis and increased cancer recurrence. Numerous studies suggest that PTEN expression levels in tumors could be a valuable biomarker for cancer diagnosis, treatment, and predicting patient outcomes. This paper provides a comprehensive review of the biological function, regulatory mechanisms, and post-translational modifications of PTEN. Furthermore, this review explores the expression and regulation of PTEN in different tumor types, as well as its interactions with environmental factors in tumorigenesis. This comprehensive analysis aims to deepen our understanding of the signaling pathways between PTEN and cancer.

Comprehensive insights into oral squamous cell carcinoma: Diagnosis, pathogenesis, and therapeutic advances

Oral squamous cell carcinoma (OSCC) is considered the most common type of head and neck squamous cell carcinoma (HNSCC) as it holds 90 % of HNSCC cases that arise from multiple locations in the oral cavity. The last three decades witnessed little progress in the diagnosis and treatment of OSCC the aggressive tumor. However, in-depth knowledge about OSCC's pathogenesis, staging & grading, hallmarks, and causative factors is a prime requirement in advanced diagnosis and treatment for OSCC patients. Therefore present review was intended to comprehend the OSCCs' prevalence, staging & grading, molecular pathogenesis including premalignant stages, various hallmarks, etiology, diagnostic methods, treatment (including FDA-approved drugs with the mechanism of action and side effects), and theranostic agents. The current review updates that for a better understanding of OSCC progress tumor-promoting inflammation, sustained proliferative signaling, and growth-suppressive signals/apoptosis capacity evasion are the three most important hallmarks to be considered. This review suggests that among all the etiology factors the consumption of tobacco is the major contributor to the high incidence rate of OSCC. In OSCC diagnosis biopsy is considered the gold standard, however, toluidine blue staining is the easiest and non-invasive method with high accuracy. Although there are various therapeutic agents available for cancer treatment, however, a few only are approved by the FDA specifically for OSCC treatment. The present review recommends that among all available OSCC treatments, the antibody-based CAR-NK is a promising therapeutic approach for future cancer treatment. Presently review also suggests that theranostics have boosted the advancement of cancer diagnosis and treatment, however, additional work is required to refine the role of theranostics in combination with different modalities in cancer treatment.

Antiapoptotic PON2 expression and its clinical implications in locally advanced oral squamous cell carcinoma

Locally advanced oral squamous cell carcinoma poses a significant challenge in oncology due to its rising incidence and mortality rates. Despite therapeutic progress, understanding molecular intricacies is essential. This study explored the role of PON2, a multifunctional enzyme implicated in antiapoptotic mechanisms. Aberrant PON2 expression in oral cancers raises questions regarding its involvement in evading programmed cell death and treatment resistance. Patients with locally advanced disease were enrolled, and molecular analyses were undertaken on the collected tumor and normal tissues. Utilizing computational datasets, this study used in silico gene expression analysis, differential gene expression analysis in our patient cohort, survival analysis, and gene set enrichment analysis to unravel role of PON2 in disease prognosis. The results showed elevated PON2 levels in advanced tumor stages, correlating with factors such as tobacco exposure, higher tumor grade, and nodal metastasis. Survival analysis revealed prognostic relevance of PON2, with lower expression linked to extended survival rates. Gene set enrichment analysis identified pathways aiding in cancer metastasis influenced by PON2. This study underscores the significance of PON2 expression as a prognostic marker for oral malignancies, with increased expression associated with advanced disease stages. Understanding the molecular profile of the PON2 gene suggests its potential as a valuable biomarker for the management of cancer.

Squamous cell carcinoma initially occurring on the tongue dorsum: a case series report with molecular analysis

BACKGROUND

Squamous cell carcinoma (SCC) of the dorsum of the tongue is extremely rare, and it clinically resembles various benign lesions. Somatic mutations in TP53 and some driver genes were implicated in the development of SCC; however, the somatic genetic characteristics of dorsal tongue SCC remain unknown. With a detailed analysis of gene mutations in dorsal tongue SCC, we aimed to better understand its biology.

METHODS

Four cases of SCC initially occurring on the tongue dorsum were evaluated for clinical and histological findings and immunohistochemical expression of p53 and p16. Gene mutations were analyzed using next-generation sequencing with a custom panel of driver genes.

RESULTS

We retrospectively investigated 557 cases of tongue SCC, and only four cases of SCC initially occurred on the tongue dorsum. The four patients (cases 1-4) were one woman and three men with a mean age of 53.75 years (range: 15-74 years). Histological analysis revealed well-differentiated SCC. Through molecular analysis, we identified pathogenic somatic mutations, namely, TP53 p.C176F (c.527G > T) in case 3 and TP53 p.R282W (c.844 C > T) in case 4. No pathogenic variants were identified in the PI3K/AKT or RAS/RAF pathways. The p53 immunohistochemical examination revealed a wild-type expression pattern in cases 1-3 and strong expression in case 4. The results of p16 immunostaining were negative in all cases.

CONCLUSIONS

We described four previously unreported genetic characteristics of dorsal tongue SCC. Somatic TP53 mutations may contribute to the development of a subset of dorsal tongue SCC; however, more cases with genetic analysis need to be accumulated.

Hippo-YAP signaling activation and cross-talk with PI3K in oral cancer: A retrospective cohort study

OBJECTIVES

This study aimed to investigate the clinical and prognostic relevance of the Hippo-YAP transactivators YAP1 and TAZ in oral squamous cell carcinoma, and their possible relationship with PI3K/mTOR pathway activation.

MATERIALS AND METHODS

Immunohistochemical analysis of YAP1, TAZ, PIK3CA (p110α), p-AKT (Ser473), and p-S6 (Ser235) was performed in paraffin-embedded tissue specimens from 165 OSCC patients. Correlations between protein expression and clinical data were further assessed.

RESULTS

YAP1 expression was detected in both cytoplasm and nucleus of tumor cells, whereas TAZ expression was only found in the nucleus. Nuclear YAP1 was significantly associated with tumor size (p = 0.03), neck lymph node metastasis (p = 0.02), TNM stage (p = 0.02), and poor differentiation (p = 0.04). Nuclear TAZ was associated with tobacco (p = 0.03) and alcohol consumption (p = 0.04), and poor tumor differentiation (p = 0.04). There was a positive significant correlation between nuclear and cytoplasmic YAP1, nuclear TAZ, p110α expression, and mTORC1 activation p-S6 (S235). Combined expression of nuclear and cytoplasmic YAP1 was prognostic in both univariate and multivariate analyses. Active nuclear YAP1 was significantly and independently associated with poor disease-specific (p = 0.005, HR = 2.520; 95% CI = 1.319-4.816) and overall survival (p = 0.015, HR = 2.126; 95% CI = 1.155-3.916).

CONCLUSION

Nuclear YAP1 is an independent predictor of poor survival in oral squamous cell carcinoma.

Knockdown of RNA-binding protein IMP3 suppresses oral squamous cell carcinoma proliferation by destabilizing E2F5 transcript

The expression level of RNA-binding proteins (RBPs) is dysregulated in oral squamous cell carcinoma (OSCC) and other types of cancer. Among the RBPs, IMP3 is involved in the progression of OSCC. However, the regulation of mRNA fate by IMP3 in OSCC remains less understood. We analyzed the expression level of IMP3 and E2F5 in OSCC tissues and cell lines by immunohistochemistry, qRT-PCR and Western blot. Subsequently, to further investigate the effect of IMP3 on E2F5 expression, we used siRNAs to silence IMP3 expression in OSCC cell lines SCC-25 and SCC-4. The binding site of E2F5 mRNA and IMP3 was confirmed by RNA immunoprecipitation (RIP). Finally, the function of IMP3 and E2F5 was investigated in viro and in xenograft mouse models. Here we report a positive correlation between IMP3 and E2F5 expression in OSCC, which are involved in cell proliferation and cell cycle. Mechanistically, E2F5 mRNA is bound by IMP3 protein, and silencing it leads to a shortened mRNA half-life and reduced protein expression. Also, knockdown of IMP3 inhibited allograft tumor progression in vivo. These studies reveal the molecular mechanism by which IMP3 regulates E2F5 mRNA stability and identify IMP3/E2F5 as a potential therapeutic target in OSCC.

Oral tumor heterogeneity, its implications for patient monitoring and designing anti-cancer strategies

Oral cancer tumors occur in the mouth and are mainly derived from oral mucosa linings. It is one of the most common and fatal malignant diseases worldwide. The intratumor heterogeneity (ITH) of oral cancerous tumor is vast, so it is challenging to study and interpret. Due to environmental selection pressures, ITH arises through diverse genetic, epigenetic, and metabolic alterations. The ITH also talks about peri-tumoral vascular/ lymphatic growth, perineural permeation, tumor necrosis, invasion, and clonal expansion/ the coexistence of multiple subclones in a single tumor. The heterogeneity offers tumors the adaptability to survive, induce growth/ metastasis, and, most importantly, escape antitumor therapy. Unfortunately, the ITH is prioritized less in determining disease pathology than the traditional TNM classifications or tumor grade. Understanding ITH is challenging, but with the advancement of technology, this ITH can be decoded. Tumor genomics, proteomics, metabolomics, and other modern analyses can provide vast information. This information in clinics can assist in understanding a tumor's severity and be used for diagnostic, prognostic, and therapeutic decision-making. Lastly, the oral tumor ITH can lead to individualized, targeted therapy strategies fighting against OC.

PAICS/DYRK3 Multienzyme Interactions as Coregulators of Purinosome Formation and Metabolism on Radioresistance in Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is a prevalent type of oral cancer. While therapeutic innovations have made strides, radioresistance persists as a significant hindrance in OSCC treatment. Despite identifying numerous targets that could potentially suppress the oncogenic attributes of OSCC, the exploration of oncogenic protein kinases for cancer therapy remains limited. Consequently, the functions of many kinase proteins in OSCC continue to be largely undetermined. In this research, we aim to disclose protein kinases that target OSCC and elaborate their roles and molecular mechanisms. Through the examination of the kinome library of radiotherapy-resistant/sensitive OSCC cell lines (HN12 and SAS), we identified a key gene, the tyrosine phosphorylation-regulated kinase 3 (DYRK3), a member of the DYRK family. We developed an in vitro cell model, composed of radiation-resistant OSCC, to scrutinize the clinical implications and contributions of DYRK3 and phosphoribosylaminoimidazole carboxylase and phosphoribosylaminoimidazolesuccinocarboxamide synthase (PAICS) signaling in OSCC. This investigation involves bioinformatics and human tissue arrays. We seek to comprehend the role of DYRK3 and PAICS signaling in the development of OSCC and its resistance to radiotherapy. Various in vitro assays are utilized to reveal the essential molecular mechanism behind radiotherapy resistance in connection with the DYRK3 and PAICS interaction. In our study, we quantified the concentrations of DYRK3 and PAICS proteins and tracked the expression levels of key pluripotency markers, particularly PPAT. Furthermore, we extended our investigation to include an analysis of Glut-1, a gene recognized for its linkage to radioresistance in oral squamous cell carcinoma (OSCC). Furthermore, we conducted an in vivo study to affirm the impact of DYRK3 and PAICS on tumor growth and radiotherapy resistance, focusing particularly on the role of DYRK3 in the radiotherapy resistance pathway. This focus leads us to identify new therapeutic agents that can combat radiotherapy resistance by inhibiting DYRK3 (GSK-626616). Our in vitro models showed that inhibiting PAICS disrupts purinosome formation and influences the survival rate of radiation-resistant OSCC cell lines. These outcomes underscore the pivotal role of the DYRK3/PAICS axis in directing OSCC radiotherapy resistance pathways and, as a result, influencing OSCC progression or therapy resistance. Our findings also reveal a significant correlation between DYRK3 expression and the PAICS enzyme in OSCC radiotherapy resistance.

Clear Cell Squamous Cell Carcinoma of the Maxillary Gingiva Associated with PIK3CA and HRAS Mutations: Report of a Case and Literature Review

BACKGROUND

Squamous cell carcinoma (SCC) is the most common oral malignancy, and somatic mutations in some driver genes have been implicated in SCC development. Clear cell SCC (CCSCC) is a rare histological variant of SCC, and various clear cell neoplasms must be considered in the differential diagnosis of CCSCC in the oral cavity. Based on a limited number of CCSCC cases reported in the oral cavity, CCSCC is considered an aggressive variant of SCC with a poor prognosis; however, its genetic characteristics remain unknown.

METHODS

A maxillary gingival tumor in an 89-year-old female was described and investigated using immunohistochemical staining, special staining, fluorescence in situ hybridization, and next-generation sequencing (NGS) with a custom panel of driver genes, including those associated with SCC and clear cell neoplasm development.

RESULTS

Histopathological examination revealed a proliferation of atypical epithelial cells with abundant clear cytoplasm and enlarged and centrally placed round nuclei. The tumor was exophytic with deep, penetrating proliferation. The atypical clear cells were continuous with the conventional SCC cells. Immunohistochemical analysis showed that the clear cells were positive for CK AE1/AE3 and CK5/6 and nuclear-positive for p63. In contrast, the clear cells were negative for αSMA, S100, HMB45, Melan-A, CD10, and p16. p53 immunoreactivity exhibited a wild-type expression pattern. Additionally, the clear cells were positive for periodic acid-Schiff (PAS) and negative for diastase-PAS, mucicarmine, and Alcian blue. Based on these results, the diagnosis of CCSCC was confirmed. Molecular analysis of the clear cells identified PIK3CA p.E542K (c.1624G>A) and HRAS p.G12A (c.35 G>C) somatic mutations classified as oncogenic. No pathogenic variants were identified in TP53, EWSR1, AKT1, PTEN, BRAF, KRAS, NRAS, RASA1, or MAML2.

CONCLUSIONS

We report a case of CCSCC of the oral cavity with PIK3CA and HRAS mutations. The identification of PIK3CA and/or HRAS mutations is rare in SCC; however, both mutations are important potential targets for antitumor therapy. A detailed analysis of gene mutations in CCSCC may lead to a better understanding of its biological behavior and an improved prognosis, as well as a differential diagnosis from other clear cell neoplasms.

Prognostic evaluation of oral squamous cell carcinoma based on pleiotrophin, urokinase plasminogen activator, and glycoprotein nonmetastatic melanoma protein B expression

This study investigated the expression of pleiotrophin (PTN), urokinase plasminogen activator (uPA), and glycoprotein nonmetastatic melanoma protein B (GPNMB) in oral squamous cell carcinoma (OSCC) tissues and their correlation with prognosis. From February 2017 to January 2020, PTN, uPA, and GPNMB expression in cancer tissues and adjacent tissues of 93 patients with OSCC was determined using immunohistochemistry. The diagnostic value of the combined detection of OSCC and its relationship with clinicopathological characteristics were analyzed, as well as the prognostic potential of PTN, uPA, and GPNMB. Cancer tissues from patients with OSCC exhibited high expression of PTN, uPA, and GPNMB. The AUC for the combined detection of PTN, uPA, and GPNMB for diagnosis and prognosis was greater than that of each index alone. The rates of expression of PTN, uPA, and GPNMB were higher in the death group than in the survival group. Patients with PTN, uPA, and GPNMB expression had lower 3-year survival rates. PTN expression was a risk factor affecting the prognosis of patients with OSCC. The rate of PTN, uPA, and GPNMB expression in OSCC tissues was high, and their expression was related to clinicopathological features such as lymph node metastasis and tumor invasion depth. The combined detection of each index has a predictive value for the prognosis of patients.

Enhancing the Effective Chemotherapy: The Combined Inhibition of Rhinacanthin-C, 5-Fluorouracil, and Etoposide on Oral Cancer Cells

OBJECTIVE

To investigate the effects of rhinacanthin-C (Rh-C), 5-FU, and etoposide on growth inhibition, as well as the effects of a combination of these inhibitors on the oral cell lines SCC9 and HSC4.

METHODS

Cancer cell growth inhibition and inhibition combination were determined using the SRB assay. Cell viability and early apoptosis were determined using flow cytometry on cells stained with Annexin 5 and PI. Western blotting was performed to study the molecular mechanism of these inhibitors on oral cancer cells.

RESULTS

The results showed that etoposide, 5-FU, and Rh-C exhibited more potent anti-proliferative effects on HSC4 cells compared to SCC9 cells in a time- and concentration-dependent manner. The combination of Rh-C and 5-FU was more effective in inhibiting cell growth than the drugs used alone. The combination of 5-FU and Rh-C resulted in a decrease in live HSC4 cells, with the highest percentage of cell death observed at a ratio of 40:6 μM. Furthermore, the combination of 5-FU and Rh-C reduced P-Akt levels leading to a decrease in cell survival.

CONCLUSIONS

HSC4 cells were found to be more sensitive to the inhibitory effect of these drugs compared to SCC9 cells. These findings suggest that the use of Rh-C as a complementary therapy with 5-FU may have the potential for the treatment of oral cancer. the underlying mechanisms responsible for this difference in sensitivity between the two cell lines need to be further investigated.

Clinical and Histopathological Factors Associated with the Tumoral Expression of TGF-β1, MED15, CD16, and CD57 in Oral Squamous Cell Carcinoma

Introduction

Factors associated with the expression of oral squamous cell carcinoma (OSCC) biomarkers “CD16, CD57, TGF-β1, and MED15” are not assessed, except in few controversial studies of some of these biomarkers. This study aimed to highlight factors that can correlate with tumoral overexpression of these biomarkers.

Methods

In this genetically-matched case-control study, biomarker expressions in all available OSCC tissues and their adjacent normal tissues at the National Tumor Center (n = 384 (4 biomarkers × (48 cancers + 48 controls))) were measured using qRT-PCR. Factors associated with tumoral overexpression of CD16, CD57, TGF-β1, and MED15 (compared to the benign control) were evaluated, using log-level multiple linear regressions and Spearman (α = 0.05).

Results

Tumoral CD16 upregulation was observed in younger patients (β = −0.284, P=0.040) and cigarette smokers (β = 0.397, P=0.005). Tumoral CD57 was upregulated in males (β = 0.341, P=0.008), smokers (β = 0.401, P=0.002), and cases without vascular invasion (β = −0.242, P=0.042). Tumoral TGF-β1 was elevated in smokers (β = 0.452, P=0.001) and smaller tumors (β = −0.322, P=0.045). Tumoral MED15 was overexpressed in smokers (β = 0.295, P=0.036) and cases lacking perineural invasion (β = −0.394, P=0.007).

Conclusion

As the most consistent finding, smoking might be positively associated with tumoral overexpression of all biomarkers. Tumoral increase in CD57 might be positively associated with metastasis while being negatively correlated with vascular and lymphatic invasion. Tumor size might be negatively associated with tumoral TGF-β1 expression.

A Signature of Three Apoptosis-Related Genes Predicts Overall Survival in Breast Cancer

Background

The commonest malignancy in women is known as breast cancer (BC). Numerous studies demonstrated that apoptosis appears to be critical to the management and clinical outcome of BC patients. The purpose of this study is to explore the potential connection between apoptosis and BC and establish the apoptosis-associated gene signature in BC.

Methods

The data of BC patient transcripts and related clinical information comes from the Cancer Genome Atlas Database (TCGA), and the genes related to apoptosis come from the Molecular Characterization Database (MSigDB). We identified the abnormally expressed apoptosis-related genes in BC samples. The optimal apoptosis-related genes screened by Cox regression analysis were designed to construct a prognostic model for predicting BC patients. Using the Nom Chart to Predict 1-Year, 3-Year, and 5-Year overall survival for BC patients. The gene signature-related functional pathways were explored by gene set enrichment analysis (GSEA).

Results

Three genes [alpha subunit of the interleukin 3 receptor (IL3RA), apoptosis-inducing factor mitochondrial-associated 1 (AIFM1), and phosphatidylinositol-3 kinase catalytic alpha (PIK3CA)] correlated with apoptosis were shown to be strongly linked to the overall survival of BC. Survival analysis shows that the risk score is directly proportional to the poor prognosis of BC patients. Risk assessment based on three genetic characteristics (age, pathological stage N, and pathological stage M) can independently predict the prognosis of patients with BC. The Nom chart is most suitable for assessing the long-term survival rate of BC patients. The results of GSEA demonstrated that numerous cell cycle-related pathways were abundant in the high-risk group.

Conclusion

We constructed an apoptosis-associated gene signature in BC, which had a potential clinical application prospect for BC patients.

High PD-L1 Expression on Tumor Cells Indicates Worse Overall Survival in Advanced Oral Squamous Cell Carcinomas of the Tongue and the Floor of the Mouth but Not in Other Oral Compartments

The markers of the tumor microenvironment (TME) are promising prognostic and predictive factors in oral squamous cell carcinoma (OSCC). The current study aims to analyze the immunohistochemical expression of programmed cell death-ligand 1 (PD-L1) and interleukin-33 (IL-33) in a cohort of 95 chemonaïve OSCCs. PD-L1 and IL-33 were assessed separately in tumor cells (TCs) and tumor-infiltrating lymphocytes (TILs). High PD-L1 expression in TILs was associated with better overall survival (OS) in univariate analysis. Tumors localized in the floor of the oral cavity and tongue tended to have a lower percentage of PD-L1-positive TCs when compared to other locations. PD-L1 expression on TCs had no prognostic significance when the whole cohort was analyzed. However, along with the T descriptor (TNM 8th), it was included in the multivariable model predicting death in carcinomas of the floor of the oral cavity and tongue (HR = 2.51, 95% CI = 1.97-5.28). In other locations, only nodal status was identified as an independent prognostic factor in multivariate analysis (HR = 0.24, 95% CI = 0.08-0.70). Expression of IL-33 had no impact on survival, but it was differently expressed in various locations. In conclusion, the prognostic significance of PD-L1 in oral cancer depends on the tumor site and type of cell expressing immune checkpoint receptor (TCs vs. TILs).

Any Role of PIK3CA and PTEN Biomarkers in the Prognosis in Oral Squamous Cell Carcinoma?

Oral squamous cell carcinoma (OSCC) accounts for 95% of the lesions in the oral cavity. Despite development in OSCC management, the outcome is still unsatisfactory. Identification of new therapies in OSCC is urgently needed. One objective of such treatment may be a signaling pathway of phosphatidylinositol 3-kinase. The study group included 92 patients treated for OSCC at the University Clinical Centre in Gdańsk, Poland. Study was performed on formalin-fixed paraffin-embedded samples from primary OSCC. Phosphatidylinositol-4,5-bisphosphate 3-kinase (PIK3CA) and phosphatase and tensin homolog encoded on chromosome 10 (PTEN) protein expression was assessed by immunohistochemistry (IHC). PIK3CA gene copy number was analyzed using chromogenic and silver in situ hybridization where molecular probes are marked by chromogens and silver ions. PIK3CA IHC H-score ≥ 70 was found in 51.65% patients, and loss of PTEN protein was noticed in 31.46% cases. PIK3CA amplification was detected in 5 tumors. In the case of PTEN protein expression, there was an inverse correlation with the T stage of the primary tumor (r = -0.243) and positive correlation with a 5-year survival (r = 0.235). The number of copies of the PIK3CA gene was associated with the tumor grading (r = 0.208). The present study shows that loss of PTEN protein and the grading (p = 0.040), distant metastases (p = 0.033), smoking (p = 0.016), and alcohol abuse (p = 0.042) were prognostic factors for the survival of patients with OSCC. In contrast, the presence of amplification and OSCC on the floor of the mouth resulted in a nearly six-fold increase in the risk of shortening survival (p = 0.037). Our finding suggests a potential prognostic significance of PTEN loss and PIK3CA amplification in OSCC. Future studies are needed to confirm our results.