Y-27632 acts beyond ROCK inhibition to maintain epidermal stem-like cells in culture.

Conditional reprogramming is a cell culture technique that effectively immortalizes epithelial cells with normal genotypes by renewing epidermal stem cells. Y-27632, a compound that promotes conditional reprogramming through an unknown mechanism, was developed to inhibit the two Rho-associated kinase (ROCK) isoforms. We used human foreskin keratinocytes (HFKs) to study the role of Y-27632 in conditional reprogramming and learn how ROCKs control epidermal stem cell renewal.

Cellular states are coupled to genomic and viral heterogeneity in HPV-related oropharyngeal carcinoma.

Head and neck squamous cell carcinoma (HNSCC) includes a subset of cancers driven by human papillomavirus (HPV). Here we use single-cell RNA-seq to profile both HPV-positive and HPV-negative oropharyngeal tumors, uncovering a high level of cellular diversity within and between tumors. First, we detect diverse chromosomal aberrations within individual tumors, suggesting genomic instability and enabling the identification of malignant cells even at pathologically negative margins.

A combination of intra-tumor genetic heterogeneity, estrogen receptor alpha and human papillomavirus status predicts outcomes in head and neck squamous cell carcinoma following chemoradiotherapy.

Background: Previous work indicates that mutant-allele tumor heterogeneity (MATH), estrogen receptor alpha (ERα) expression, and human papillomavirus (HPV) status provide prognostic utility in head and neck squamous cell carcinoma (HNSCC). We sought to assess whether the combination of these three objective biomarkers could provide better prognostication for patients who receive chemoradiotherapy (CRT).

Methods: 156 patients (75 oral cavity, 44 oropharyngeal and 37 laryngeal squamous cell carcinoma cancer patients) who received CRT as primary therapy or adjuvant to surgery were identified from The Cancer Genome Atlas (TCGA).

Time to Surgery and Survival in Head and Neck Cancer.

Background: The COVID-19 pandemic has required triage and delays in surgical care throughout the world. The impact of these surgical delays on survival for patients with head and neck squamous cell carcinoma (HNSCC) remains unknown.

Methods: A retrospective cohort study of 37 730 patients in the National Cancer Database with HNSCC who underwent primary surgical management from 2004 to 2016 was performed.

Intratumor heterogeneity could inform the use and type of postoperative adjuvant therapy in patients with head and neck squamous cell carcinoma.

Background: After surgery for head and neck squamous cell carcinoma (HNSCC), decisions regarding adjuvant radiotherapy (RT) or chemoradiotherapy (CRT) are based on staging and the presence of high-risk pathology. Because higher mutant allele tumor heterogeneity (MATH; a measure of intratumor genetic heterogeneity) is associated with shorter overall survival (OS) in patients with HNSCC, the authors sought to determine whether MATH analysis might further inform these decisions.

Methods: Adjuvant therapy-associated relationships between MATH and OS were analyzed for 389 patients with HNSCC who were treated surgically.

Association of Estrogen Receptor Alpha Expression With Survival in Oropharyngeal Cancer Following Chemoradiation Therapy.

Background: Oropharyngeal squamous carcinoma (OPSC) continues to increase in incidence secondary to human papillomavirus (HPV) infection. Despite the good overall prognosis for these patients, treatment with chemoradiation is associated with morbidity and treatment failure. Better predictors for disease outcome are needed to guide de-intensification regimens.

Single-Cell Transcriptomic Analysis of Primary and Metastatic Tumor Ecosystems in Head and Neck Cancer.

The diverse malignant, stromal, and immune cells in tumors affect growth, metastasis, and response to therapy. We profiled transcriptomes of ∼6,000 single cells from 18 head and neck squamous cell carcinoma (HNSCC) patients, including five matched pairs of primary tumors and lymph node metastases. Stromal and immune cells had consistent expression programs across patients.

Intra-tumor heterogeneity in head and neck cancer and its clinical implications.

The presence of heritable differences among cancer cells within a tumor, called intra-tumor genetic heterogeneity, has long been suspected of playing a role in poor responses to therapy. Research over the past decade has documented the existence of such heterogeneity within tumors of individual patients and documented its potential clinical significance. The research methods for identifying this heterogeneity were not, however, readily adaptable to widespread clinical application.

The challenges of tumor genetic diversity.

The authors review and discuss the implications of genomic analyses documenting the diversity of tumors, both among patients and within individual tumors. Genetic diversity among solid tumors limits targeted therapies, because few mutations that drive tumors are both targetable and at high prevalence. Many more driver mutations and how they affect cellular signaling pathways must be identified if targeted therapy is to become widely useful.

Comparison of the Genomic Landscape Between Primary Breast Cancer in African American Versus White Women and the Association of Racial Differences With Tumor Recurrence.

Purpose: African American women are more likely to die as a result of breast cancer than white women. The influence of somatic genomic profiles on this racial disparity is unclear. We aimed to compare the racial distribution of tumor genomic characteristics and breast cancer recurrence.

Intra-tumor genetic heterogeneity and mortality in head and neck cancer: analysis of data from the Cancer Genome Atlas.

Background: Although the involvement of intra-tumor genetic heterogeneity in tumor progression, treatment resistance, and metastasis is established, genetic heterogeneity is seldom examined in clinical trials or practice. Many studies of heterogeneity have had prespecified markers for tumor subpopulations, limiting their generalizability, or have involved massive efforts such as separate analysis of hundreds of individual cells, limiting their clinical use. We recently developed a general measure of intra-tumor genetic heterogeneity based on whole-exome sequencing (WES) of bulk tumor DNA, called mutant-allele tumor heterogeneity (MATH).

Impact of human papillomavirus on oropharyngeal cancer biology and response to therapy: implications for treatment.

Oropharyngeal squamous cell carcinoma (OPSCC) originating from human papillomavirus infection has emerged as a new entity in head and neck cancer, defining a subset of patients with distinct carcinogenesis, risk factor profiles, and clinical presentation that show markedly improved survival than patients with classic OPSCC. De-escalation of therapy and identification of relevant biomarkers to aid in patient selection are actively being investigated. This review addresses the implications of these findings in clinical care.

High intratumor genetic heterogeneity is related to worse outcome in patients with head and neck squamous cell carcinoma.

Background: Although the presence of genetic heterogeneity within the tumors of individual patients is established, it is unclear whether greater heterogeneity predicts a worse outcome. A quantitative measure of genetic heterogeneity based on next-generation sequencing (NGS) data, mutant-allele tumor heterogeneity (MATH), was previously developed and applied to a data set on head and neck squamous cell carcinoma (HNSCC). Whether this measure correlates with clinical outcome was not previously assessed.

MATH, a novel measure of intratumor genetic heterogeneity, is high in poor-outcome classes of head and neck squamous cell carcinoma.

Objectives: Differences among cancer cells within a tumor are important in tumorigenesis and treatment resistance, yet no measure of intratumor heterogeneity is suitable for routine application. We developed a quantitative measure of intratumor genetic heterogeneity, based on differences among mutated loci in the mutant-allele fractions determined by next-generation sequencing (NGS) of tumor DNA. We then evaluated the application of this measure to head and neck squamous cell carcinoma (HNSCC).

Bcl2 and human papilloma virus 16 as predictors of outcome following concurrent chemoradiation for advanced oropharyngeal cancer.

Purpose: Oropharyngeal squamous cell carcinoma (OPSCC) associated with human papilloma virus (HPV) is rapidly growing in incidence. Despite better prognosis than OPSCC associated with traditional risk factors, treatment failure still occurs in a significant proportion of patients. We had identified the antiapoptotic protein Bcl2 as a marker for poor outcome in advanced OPSCC treated with concurrent chemoradiation.

Bcl-2 blocks cisplatin-induced apoptosis and predicts poor outcome following chemoradiation treatment in advanced oropharyngeal squamous cell carcinoma.

Purpose: This study aimed to test the hypothesis that elevated expression of antiapoptotic Bcl-2 family proteins predicts a poor therapeutic response of oropharyngeal squamous cell carcinoma (OPSCC) to concurrent platinum-based chemoradiation therapy.

Experimental Design: Levels of Bcl-2, Bcl-XL, and Bcl-w were determined and correlated with resistance to cisplatin in a large panel of cell lines derived from squamous cell carcinoma of the head and neck (HNSCC). Univariate and multivariate analyses were used to evaluate the relationship between Bcl-2 and Bcl-XL expression and disease-free survival following chemoradiation therapy in a uniformly treated cohort of patients with OPSCC.

HPV-16 infection predicts treatment outcome in oropharyngeal squamous cell carcinoma.

Objective: To determine if patients with human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma (OPSCC) treated with chemoradiation have improved outcomes.

Study Design: A retrospective search was used to identify patients with OPSCC treated with concurrent chemoradiation. Pretreatment biopsy specimens were tested for HPV-16 infection and p16 expression.

COOH-terminal binding protein regulates expression of the p16INK4A tumor suppressor and senescence in primary human cells.

The p16/pocket-protein pathway sets a balance between tumor suppression and capacity for tissue regeneration. Understanding the upstream signaling pathway that turns on the expression of p16 is required both for knowing the tumorigenic stresses from which this pathway provides protection and for appreciating the selective pressure that leads to the loss of this pathway in most human tumors. We report that COOH-terminal binding protein (CtBP), a physiologically regulated transcriptional corepressor that dimerizes to hold together repressive complexes, regulates p16 expression in primary human fibroblasts and keratinocytes.

RNA interference: natural, experimental, and clinical roles in cancer biology.

The old idea of using antisense RNA to block messenger RNA has recently led to powerful new techniques for knocking down expression of individual protein-coding genes. The simplicity and general applicability of these new methods for RNA interference (RNAi) have turned them into fundamental tools in molecular and cellular biology, with more than 5000 publications using them during the few years since they were developed. These experimental methods are now known to exploit fundamental cellular processes that regulate differentiation via genomically encoded RNAi sequences known as microRNAs (miRNAs); changes in endogenous microRNA regulation have now been implicated in oncogenesis.