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PML involvement in the p73-mediated E1A-induced suppression of EGFR and induction of apoptosis in head and neck cancers.

ABSTRACT: Epidermal growth factor receptor (EGFR) tyrosine kinase is commonly overexpressed in human cancers; however, the cellular mechanisms regulating EGFR expression remain unclear. p53, p63 and p73 are transcription factors regulating many cellular targets involved in controlling the cell cycle and apoptosis. p53 activates EGFR expression, whereas TAp63 represses EGFR transcription. The involvement of p73 in the regulation of EGFR has not been reported. Here, a strong correlation between EGFR overexpression and increased levels of the oncogenic DeltaNp73 isoform in head and neck squamous cell carcinoma (HNSCC) cell lines was observed. Ectopic expression of TAp73, particularly TAp73beta, resulted in suppression of the EGFR promoter, significant downregulation of EGFR protein and efficient induction of cell death in all six EGFR-overexpressing HNSCC cell lines. EGFR overexpression from a heterologous LTR promoter protected lung cancer cells from TAp73beta-induced EGFR suppression and apoptosis. Expression of TAp73beta efficiently induced promyelocytic leukaemia (PML) protein expression and PML knockdown by shRNA attenuated the downregulation of EGFR and induction of apoptosis by p73 in HNSCC cells. Furthermore, PML was found to be important for E1A-induced suppression of EGFR and subsequent killing of HNSCC cells. Our data therefore suggest a novel pathway involving PML and p73 in the regulation of EGFR expression.

SUBMITTER: Klanrit P

PROVIDER: S-EPMC2882231 | biostudies-literature | 2009 Oct

REPOSITORIES: biostudies-literature

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PML involvement in the p73-mediated E1A-induced suppression of EGFR and induction of apoptosis in head and neck cancers.

Klanrit P P Taebunpakul P P Flinterman M B MB Odell E W EW Riaz M A MA Melino G G Salomoni P P Mymryk J S JS Gäken J J Farzaneh F F Tavassoli M M

Oncogene 20090713 39

Epidermal growth factor receptor (EGFR) tyrosine kinase is commonly overexpressed in human cancers; however, the cellular mechanisms regulating EGFR expression remain unclear. p53, p63 and p73 are transcription factors regulating many cellular targets involved in controlling the cell cycle and apoptosis. p53 activates EGFR expression, whereas TAp63 represses EGFR transcription. The involvement of p73 in the regulation of EGFR has not been reported. Here, a strong correlation between EGFR overexp ...[more]

PMID: 19597475

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Project description:This review focuses on the molecular biology of head and neck squamous cell carcinomas and presents current and emerging biomarkers of the response of patients to induction chemotherapy. The usefulness of genes, proteins, and parameters from diagnostic clinical imaging as well as other clinicopathological parameters is thoroughly discussed. The role of induction chemotherapy before radiotherapy or before chemo-radiotherapy is still debated, as the data on its efficacy are somehow confusing. Despite the constant improvement of treatment protocols and the introduction of new cytostatics, there is still no consensus regarding the use of induction chemotherapy in the treatment of head and neck cancer, with the possible exception of larynx preservation. Such difficulties indicate that potential future treatment strategies should be personalized. Personalized medicine, in which individual tumor genetics drive the selection of targeted therapies and treatment plans for each patient, has recently emerged as the next generation of cancer therapy. Early prediction of treatment outcome or its toxicity may be highly beneficial for those who are at risk of the development of severe toxicities or treatment failure-a different treatment strategy may be applied to these patients, sparing them unnecessary pain. The literature search was carried out in the PubMed and ScienceDirect databases as well as in the selected conference proceedings repositories. Of the 265 articles and abstracts found, only 30 met the following inclusion criteria: human studies, analyzing prediction of induction chemotherapy outcome or toxicity based on the pretreatment (or after the first cycle, if more cycles of induction were administered) data, published after the year 2015. The studies regarding metastatic and recurrent cancers as well as the prognosis of overall survival or the outcome of consecutive treatment were not taken into consideration. As revealed from the systematic inspection of the papers, there are over 100 independent parameters analyzed for their suitability as prognostic markers in HNSCC patients undergoing induction chemotherapy. Some of them are promising, but usually they lack important features such as high specificity and sensitivity, low cost, high positive predictive value, clinical relevance, short turnaround time, etc. Subsequent studies are necessary to confirm the usability of the biomarkers for personal medicine.

Project description:Cancer progression can be understood as the result of deregulation of tumors' immune microenvironments. Recent studies of the alterations of microenvironments highlight their significant influence on the prognosis of patients with head and neck squamous cell carcinoma (HNSCC). It is necessary to better characterize tumor-infiltrating lymphocytes by focusing, in particular, on the tumor escape mechanisms from immune surveillance. One of the best described tumor immune system evasion mechanisms is the expression of co-stimulation molecules that constitute so-called "immune checkpoints". These molecules regulate the immune response by either activating or inhibiting its effects. The programmed cell death 1 (PD-1) surface protein is an inhibitory co-stimulation molecule that induces exhaustion of activated T-lymphocytes (TLs, T cells) through binding with its ligands, PD-L1 and PD-L2. Half of HNSCCs exhibit PD-L1 expression with higher expression identified in human papillomavirus (HPV) positive tumors. Numerous studies have shown differences between the microenvironments of HPV+?and HPV- cancers. Notably, infiltrations of exhausted CD4+?PD1+?and CD8+?PD1+?T cells are far higher in the microenvironment of HPV+?tumors. The FDA has approved the use of molecules that target PD-1 for the treatment of HNSCC. The first results of clinical trials with anti-PD-1 blockers in HNSCC show improved patient survival, particularly long-term survival without recurrence. However, discordant results were sometimes observed, and improvements in defining cellular predictive markers are necessary. With the development of immunotherapies, pathologists play a role in the selection of patients who are eligible for specific treatments and assessment of their prognosis in greater detail. An automated, quantitative in situ imaging system that integrates both multispectral imaging and automated slide scanning could be developed in pathology laboratories. The evaluation of PD-L1 expression has only been used to stratify the administration of first-line immunotherapy. The validation of these tests and their routine interpretation is essential. No specific recommendation is adopted for HPV+?HNSCC.

Project description:BackgroundThe rate of toxic deaths related to induction chemotherapy in the treatment of locally advanced head and neck cancers is unacceptable and calls into question this therapeutic strategy, which is however highly effective in terms of rate and speed of response. The purpose of the study was to investigate predictive factors of toxicity of induction chemotherapy with docetaxel, cisplatin, and 5-fluorouracil (TPF) in locally advanced head and neck cancers (LAHNC).MethodsBetween June 2009 and December 2017, 113 patients treated consecutively with TPF were included retrospectively. Patients were receiving induction chemotherapy for either an inoperable cancer or laryngeal preservation. For inoperable cancer, induction chemotherapy was proposed to patients presenting either a large tumor with strong symptoms (dyspnea, dysphagia, pain) or a tumor with rapid progression. Risk factors were chosen among the initial patient and tumour characteristics and chemotherapy modalities.ResultsEighty-nine patients (79%) were male; the median age was 58 years [32-71]. Sixty-nine (61%) patients were treated for inoperable cancer and 44 (39%) for laryngeal preservation. 45% had stage IVa cancer, 28% stage III and 25% stage IVb. Sixty percent of patients had a partial response after TPF, 22% had a complete response, 12% were stable, 5% were progressing, and 1% had a discordant response. Thirty-four patients (30%) received enteral feeding during induction chemotherapy with TPF. The possibility of oral feeding without a tube was predictive of a better response (p = 0.003). Seven (6%) patients died during TPF. There was an increased risk of death with preexisting liver dysfunction (liver dysmorphia on imaging or decrease prothrombin rate) (p = 0.032). There was an increased risk of grade ≥ 3 infection if an enteral feeding occurred during the period of induction chemotherapy (p = 0.03).ConclusionsTPF induction chemotherapy had an 82% objective response rate with 6% toxic deaths. Nutritional status and the presence of hepatic dysfunction are significant risk factors to be taken into account in therapeutic decisions.

Dataset Information

PML involvement in the p73-mediated E1A-induced suppression of EGFR and induction of apoptosis in head and neck cancers.

Publications

PML involvement in the p73-mediated E1A-induced suppression of EGFR and induction of apoptosis in head and neck cancers.

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