Divergence of P53, PTEN, PI3K, Akt and mTOR expression in tonsillar cancer

Defining the Molecular Intricacies of Human Papillomavirus-Associated Tonsillar Carcinoma

BackgroundThe past decade has shown a sharp incline in the human papillomavirus (HPV) infection associated oropharyngeal carcinoma cases, especially in men younger than 60 years old. Tonsils are one of the key sites, within the oropharyngeal region, which shows malignant changes due to HPV infection, and there is very limited literature to understand the specific dynamics in the tonsillar areas.ObjectiveThis critical review was undertaken to explore and unravel the bio-molecular interactions and the role of specific proteins associated with HPV infection induced tumorigenesis for the tonsils.DesignA systematic search of the literature was performed utilising keywords and MeSH terms related to HPV and tonsillar carcinoma in PubMed, Scopus, Embase, and Web of Science without restrictions on dates until July 2023. All studies that reported on molecular biomarkers or genes/genetic proteins in the context of HPV associated tonsillar carcinoma were included in the study.ResultsPreliminary searches revealed a total of 2734 studies of which 23 satisfied the final inclusion criteria and were included. More than 25 proteins and biomarkers were identified, and their role in the malignant process was extracted and compiled. This review also presents a short excerpt on each of the molecules identified to provide a better understanding of the pathogenesis.ConclusionGiven the rapidly increasing number of cases, there is an urgent need for more focused research on virally induced tonsillar cancers, to develop a better understanding, and for clarity of management and treatment.

Clinical and molecular characteristics of Jordanian oropharyngeal cancer patients according to P16 expression: a retrospective study and a report of a novel biomarker

The purpose of this study was to assess the clinicopathological features of oropharyngeal cancer patients in Jordan based on their HPV status. Sixty-nine biopsies from two hospitals were included. Tissue microarrays were prepared from formalin-fixed paraffin-embedded (FFPE) specimens and stained with antibodies for CDKN2A/P16, EGFR, PI3K, PTEN, AKT, pS473AKT, PS2mTOR, and TIMAP. The cohort was divided according to P16 expression. Chi-square test and survival analyses were employed to evaluate the variations among the study variables and determine the prognostic factors, respectively. P16 expression was found in 55.1% of patients; however, there was no significant association between P16 expression and the patients' clinicopathological features. The Kaplan-Meier test revealed that smoking in P16-positive group and younger age (< 58 years) negatively impacted disease-free survival (DFS) (P = 0.04 and P = 0.003, respectively). Multivariate Cox regression test indicated that smoking, age, PI3K, and AKT were negative predictors of DFS (P = 0.021, P = 0.002, P = 0.021, and P = 0.009, respectively), while TIMAP was a positive predictor (P = 0.045). Elevated P16 expression is found in more than half of the patients' specimens. DFS is negatively affected by younger age and the combined effect of smoking and P16 overexpression. TIMAP is overexpressed in P16-positive oropharyngeal cancer, and it is a favorable predictor of DFS.

PI3K/AKT/mTOR Signaling Pathway in HPV-Driven Head and Neck Carcinogenesis: Therapeutic Implications

High-risk human papillomaviruses (HR-HPVs) are the causal agents of cervical, anogenital and a subset of head and neck carcinomas (HNCs). Indeed, oropharyngeal cancers are a type of HNC highly associated with HR-HPV infections and constitute a specific clinical entity. The oncogenic mechanism of HR-HPV involves E6/E7 oncoprotein overexpression for promoting cell immortalization and transformation, through the downregulation of p53 and pRB tumor suppressor proteins, among other cellular targets. Additionally, E6/E7 proteins are involved in promoting PI3K/AKT/mTOR signaling pathway alterations. In this review, we address the relationship between HR-HPV and PI3K/AKT/mTOR signaling pathway activation in HNC with an emphasis on its therapeutic importance.

Nuclear PTEN's Functions in Suppressing Tumorigenesis: Implications for Rare Cancers

Phosphatase and tensin homolog (PTEN) encodes a tumor-suppressive phosphatase with both lipid and protein phosphatase activity. The tumor-suppressive functions of PTEN are lost through a variety of mechanisms across a wide spectrum of human malignancies, including several rare cancers that affect pediatric and adult populations. Originally discovered and characterized as a negative regulator of the cytoplasmic, pro-oncogenic phosphoinositide-3-kinase (PI3K) pathway, PTEN is also localized to the nucleus where it can exert tumor-suppressive functions in a PI3K pathway-independent manner. Cancers can usurp the tumor-suppressive functions of PTEN to promote oncogenesis by disrupting homeostatic subcellular PTEN localization. The objective of this review is to describe the changes seen in PTEN subcellular localization during tumorigenesis, how PTEN enters the nucleus, and the spectrum of impacts and consequences arising from disrupted PTEN nuclear localization on tumor promotion. This review will highlight the immediate need in understanding not only the cytoplasmic but also the nuclear functions of PTEN to gain more complete insights into how important PTEN is in preventing human cancers.

Cadmium and molybdenum co-induce pyroptosis and apoptosis by PTEN/PI3K/AKT axis in the liver of ducks

Cadmium (Cd) and excessive molybdenum (Mo) have adverse impacts on animals. However, the hepatotoxicity co-induced by Cd and Mo in ducks has not been fully elucidated. In order to explore...

Knockdown of Forkhead box A1 suppresses the tumorigenesis and progression of human colon cancer cells through regulating the phosphatase and tensin homolog/Akt pathway

Background

This study aimed to evaluate the role and the underlying mechanisms of Forkhead box A1 (encoded by FOXA1) in colon cancer.

Methods

We analyzed FOXA1 mRNA and protein expression in colon cancer tissues and cell lines. We also silenced FOXA1 expression in HCT116 and SW480 cells to evaluate the effects on cell proliferation, cell cycle, migration, and invasion by using MTT, colony formation, flow cytometry, and the Transwell assay, respectively.

Results

FOXA1 immunostaining was higher in colon cancer tissues than adjacent healthy tissues. FOXA1 mRNA and protein expression was significantly increased in human colon cancer cells compared with a normal colonic cell line. FOXA1 expression was also significantly higher in colorectal cancer tissues from TCGA data sets and was associated with worse prognosis in the R2 database. FOXA1 expression was negatively correlated with the extent of its methylation, and its knockdown reduced proliferation, migration, and invasion, and induced G2/M phase arrest in HCT116 and SW480 cells by suppressing the phosphatase and tensin homolog/Akt signaling pathway and inhibiting epithelial–mesenchymal transition.

Conclusion

FOXA1 may act as an oncogene in colon cancer tumorigenesis and development.

β-elemene suppresses the malignant behavior of esophageal cancer cells by regulating the phosphorylation of AKT

BACKGROUND

Esophageal cancer is a digestive tract malignancy, ranking sixth among the world's deadliest tumor incidence. However, the pathogenesis of esophageal cancer is complex and the prognosis remains poor. Therefore, in-depth study of the pathogenesis and developing effective treatments are of great value for esophageal cancer. β-elemene is a natural monomeric compound derived from the Chinese herbal Curcuma wenyujin. β-elemene has been reported to have anti-tumor effects and used as an adjunct to clinical therapy for multiple cancers. This study aims to explore the effects of β-elemene on esophageal cancer and its related molecular mechanisms.

METHODS

TE-1 and KYSE-150 cells were used to evaluate the activity of β-elemene on esophageal cancerin vitro and in vivo. Western blot was performed for protein expression assessment. CCK8 assay and cell cycle analysis were used for proliferation testing. Flow cytometry was performed for apoptosis detection. Wound healing assay was subjected to assess the migration ability. Transwell chamber assay was applied to assess the invasion ability. HE staining, TUNEL staining and immunohistochemical staining were used to evaluate the changes in tumor tissues.

RESULTS

We found that β-elemene treatment suppressed proliferation, as well as induced apoptosis of esophageal cancer cells. In addition, β-elemene inhibited the migration and invasion ability of esophageal cancer cells. Furthermore, β-elemene exerted its effects against esophageal cancer by specifically regulating AKT signaling, thereby controlling the expression of PD-L1.

CONCLUSION

β-elemene inhibits proliferation and metastasis of esophageal cancer cells by regulating the phosphorylation of AKT.

PTEN loss is associated with resistance to cetuximab in patients with head and neck squamous cell carcinoma

INTRODUCTION

Cetuximab, a monoclonal antibody to the epidermal growth factor receptor (EGFR), extends survival in combination with standard therapy in head and neck squamous cell carcinoma (HNSCC). However, as effects are modest, and patients experience side effects, a biomarker to predict resistance and personalize therapy is needed. Activation of signaling pathways downstream from receptor tyrosine kinases predicts resistance to such therapies in other cancers. The most common abnormalities downstream from EGFR in HNSCC are in the PI3K pathway, activated via loss of expression of the regulator PTEN, or via PI3K mutation. We studied whether PTEN and/or PI3K abnormalities predict resistance to cetuximab.

METHODS

Tumor PTEN and PIK3CA/PI3K p110α were analyzed in samples from subjects treated on two trials of cetuximab-based therapy for patients with metastatic or recurrent HNSCC: E5397, a randomized trial of cisplatin plus placebo versus cisplatin plus cetuximab; and NCI-8070, a randomized trial of cetuximab plus sorafenib versus cetuximab. In situ quantification of PTEN and PI3K p110 α was performed using the AQUA™ method of quantitative immunofluorescence. PI3KCA hot spot mutations were determined with BEAMing.

RESULTS

For E5397, in multivariable analysis, PTEN expressing/PIK3CA WT patients tended to improve PFS with cetuximab compared to placebo (N = 48; HR = 0.54, Wald p = 0.0502). High PTEN expression was significantly associated with superior PFS among patients treated on NCI-8070 (N = 37; HR = 0.35, p = 0.008).

CONCLUSION

Loss of PTEN expression may be associated with lack of benefit from cetuximab. This analysis is limited by small sample size, and PTEN as a potential predictive biomarker merits validation in larger sample sets.

β-elemene induced anticancer effect in bladder cancer through upregulation of PTEN and suppression of AKT phosphorylation

Human bladder cancer is one of the most aggressive tumours known and has shown resistance to traditional chemotherapy, which depends heavily on DNA-damaging drugs. β-elemene is one of the least cytotoxic antitumor agents that are extracted from Curcuma aromatica salisb and it exhibits antitumor effects in many carcinomas. β-elemene has attracted the attention of clinicians and scientists worldwide due to its few side effects and limited effect on the bone marrow. However, the antitumor mechanism of β-elemene remains largely unstudied. In the present study, the expression of the AKT serine/threonine kinase (AKT) signaling pathway in bladder cancer and normal bladder tissue was investigated, and the influence of β-elemene on bladder cancer cells and the mechanisms involved were assessed. The results showed that phosphatase and tensin homolog deleted on chromosome ten (PTEN) was downregulated and phosphorylated-AKT (pAKT) was overexpressed in human bladder cancer. β-elemene significantly suppressed the viability of bladder cancer cells, while leaving normal bladder cells unaffected. In addition, there was an increased number of apoptotic bladder cancer cells following β-elemene treatment, and a significant reduction in cell invasion and migration. Subsequent western blot analyses revealed that bladder cancer cells treated with β-elemene had increased PTEN expression and decreased expression of pAKT. Taken together, these results suggest that β-elemene has an antitumor effect in bladder cancer cells through the upregulation of PTEN and suppression of AKT phosphorylation.

Comparison of PI3K Pathway in HPV-Associated Oropharyngeal Cancer With and Without Tobacco Exposure

Objectives

The aim of the study was to evaluate whether HPV associated OPSCC with tobacco exposure follows a different carcinogenic pathway compared to HPV associated OPSCC without tobacco exposure and to investigate its prognostic significance. The question was addressed with focus on components of the PI3K pathway.

Methods

184 patients with newly diagnosed OPSCC treated with curative intent were consecutively enrolled. The expression level of p16, p53, PI3K, mTOR, and PTEN was assessed by immunohistochemistry and analyzed in relation to the risk factors HPV status and tobacco exposure.

Results

94 of 184 (51%) patients were p16 positive, p53 overexpression was detected in 48 of 184 (26%) cases. PI3K overexpression with 70 of 184 (38%) cases was significantly higher in p16 positive tumors. mTOR overexpression was present in 90 of 184 (49%) cases and significantly higher in p16 negative tumors. PTEN loss was found in 42 of 184 (23%) cases without association to p16 expression. p16 positive OPSCC showed lower rates of p53 expression and mTOR expression as well as higher rates of PI3K expression irrespective of tobacco exposure. Survival analysis showed a distinct intermediate survival rate of p16 positive smokers. The markers PI3K, mTOR, and PTEN did not have a significant impact on survival.

Conclusion

HPV associated OPSCC with tobacco exposure follows the same expression level of the PI3K pathway as HPV associated OPSCC without tobacco exposure. The impaired survival rate of the intermediate risk group cannot be explained by different expression patterns of PI3K, mTOR, and PTEN.

Level of Evidence

2b

miR-26a promoted endometrial epithelium cells (EECs) proliferation and induced stromal cells (ESCs) apoptosis via the PTEN-PI3K/AKT pathway in dairy goats

Changes in endometrial cell morphology and function are absolutely necessary for successful embryo implantation. In this study, miR-26a was widely expressed in dairy goats, and was found to be regulated by β-estradiol (E2) and progesterone (P4) in endometrial epithelium cells (EECs) as well as stromal cells (ESCs). Furthermore, miR-26a played a role in the regulation of cells proliferation and apoptosis by directly regulating PTEN and indirectly regulating the PI3K/AKT pathway in EECs but not in ESCs of dairy goats in vitro. In addition, miR-26a regulated the expression of osteopontin (OPN), vascular endothelial growth factor (VEGF), Cyclooxygenase-2 (COX-2), and prolactin (PRL) in endometrial cells. Therefore, we could get a conclusion that miR-26a had very complex and diverse functions in the endometrial cells during the development of endometrial receptivity in dairy goats. This study provided an efficient platform for studying the regulatory effect of miR-26a on endometrial cells during the development of endometrial receptivity in dairy goats.

Biomarker driven treatment of head and neck squamous cell cancer

Abstract

Treatment modalities of head and neck squamous cell cancer include surgery, radiation, chemotherapy, targeted agents and immune checkpoint inhibition. Treatment is often toxic and can affect long-term function and quality of life. In this context, identification of biomarker data that can help tailor therapy on an individualized basis and reduce treatment-related toxicity would be highly beneficial. A variety of predictive biomarkers have been discovered and are already utilized in clinical practice, while many more are being explored. We will review p16 overexpression as a surrogate biomarker in HPV-associated head and neck cancer and plasma EBV DNA as a biomarker in nasopharyngeal carcinoma, the two established biomarkers currently utilized in clinical practice. We will also examine novel predictive biomarkers that are in clinical development and may shape the future landscape of targeted head and neck cancer therapy. These emerging biomarkers include the tyrosine kinases and their signaling pathway, immune checkpoint biomarkers, tumor suppressor abnormalities, and molecular predictors of hypoxia-targeted therapy. We will also look at futuristic biomarkers including detection of circulating DNA from clinical specimens and rapid tumor profiling. We will highlight the ongoing effort that will see a shift from prognostic to predictive biomarker development in head and neck cancer with the goal of delivering individualized cancer therapy.

Trial registration

N/A.

A proportion of primary squamous cell carcinomas of the parotid gland harbour high-risk human papillomavirus

AIMS

In the current study, we aimed to examine primary parotid squamous cell carcinoma (ParSCC) for the presence of high-risk human papillomavirus (HR-HPV) and associated molecular alterations.

METHODS AND RESULTS

Eight cases of ParSCC were retrieved after a detailed clinicopathological review to exclude the possibility of metastasis and/or extension from another primary site. HR-HPV status was determined on the basis of immunohistochemistry (IHC) for p16 expression and chromogenic in-situ hybridization (CISH) for HR-HPV. All cases were genotyped with a multiplexed mass spectrometry assay interrogating 91 hotspot mutations in eight cancer-related genes (EGFR, KRAS, NRAS, BRAF, PIK3CA, AKT1, MEK1 and ERBB2), and studied by fluorescence in-situ hybridization for PTEN copy number alteration. Three of eight cases (37.5%) were positive for the presence of HR-HPV by CISH and p16 IHC. One of three (33%) HR-HPV-positive cases harboured a PTEN hemizygous deletion, and one (33%) HR-HPV-positive case harboured a PIK3CA E545K somatic mutation. No alteration of the PTEN-PI3K pathway was detected in HR-HPV-negative tumours. Over a median follow-up period of 66.2 months, only the patient with the HR-HPV-positive PIK3CA-mutated tumour died of his disease, the remaining seven patients being disease-free.

CONCLUSIONS

Given the established aetiological role of HR-HPV in other head and neck squamous cell carcinomas, it is likely that HR-HPV represents an oncogenic driver in the pathogenesis of more than one-third of ParSCCs. The presence of HR-HPV in ParSCC may be coupled with alterations in the PTEN-PI3K pathway. Further studies on HR-HPV and the molecular characterization of a larger number of ParSCCs are needed to determine the clinical significance of these findings.

Increased radiosensitivity of HPV-positive head and neck cancers: Molecular basis and therapeutic perspectives

Human papillomavirus driven head and neck squamous cell carcinoma (HNSCC), particularly oropharyngeal squamous cell carcinoma (OPSCC), are characterized by a significant survival advantage over their HPV-negative counterparts. Although the reasons behind this are still not fully elucidated, it is widely accepted that these tumors have a higher response to ionizing radiation that might explain their favorable outcomes. Potential underlying intrinsic mechanisms include impaired DNA repair abilities, differences in activated repopulation-signaling pathways and cell cycle control mechanisms. The role of the microenvironment is increasingly highlighted, particularly tumor oxygenation and the immune response. Recent studies have shown a distinct pattern of intratumoral immune cell infiltrates, according to HPV status, and have suggested that an increased cytotoxic T-cell based antitumor immune response is involved in improved prognosis of patients with HPV-positive OPSCC. These significant milestones, in the understanding of HPV-induced HNSCC, pave the way to new therapeutic opportunities. This article reviews the current evidence on the biological basis of increased radiosensitivity in HPV-positive HNSCC and discusses potential therapeutic implications.