Mutational load and mutational patterns in relation to age in head and neck cancer

Exploration of prognostic biomarkers in head and neck squamous cell carcinoma microenvironment from TCGA database

Background

Immune checkpoint blockade (ICB) therapies have redefined human cancer treatment, including for head and neck squamous cell carcinoma (HNSCC). However, clinical responses to various immune checkpoint inhibitors are often accompanied by immune-related adverse events (irAEs). Therefore, it is crucial to obtain a comprehensive understanding of the association between different immune tumor microenvironments (TMEs) and the immunotherapeutic response.

Methods

The research data were obtained from The Cancer Genome Atlas (TCGA) database. We applied RNA-seq genomic data from tumor biopsies to assess the immune TME in HNSCC. As the TME is a heterogeneous system that is highly associated with HNSCC progression and clinical outcome, we relied on the Estimation of Stromal and Immune cells in Malignant Tumor tissues using Expression data (ESTIMATE) algorithm to calculate immune and stromal scores that were evaluated based on the immune or stromal components in the TME. Then, the Tumor Immune Dysfunction and Exclusion algorithm (TIDE) was used to predict the benefits of ICB to each patient. Finally, we identified specific prognostic tumor-infiltrating immune cells (TIICs) by quantifying the cellular composition of the immune response in HNSCC and its association to survival outcome, using the CIBERSORT algorithm.

Results

Utilizing the HNSCC cohort of the TCGA database and TIDE and ESTIMATE algorithm-derived immune scores, we obtained a list of microenvironment-associated lncRNAs that predicted different clinical outcomes in HNSCC patients. We validated these correlations in a different HNSCC cohort available from the TCGA database and provided insight into the prediction of response to ICB therapies in HNSCC.

Conclusions

This study confirmed that CD8⁺ T cells were significantly associated with better survival in HNSCC and verified that the top five significantly mutated genes (SMGs) in the TCGA HNSCC cohort were TP53, TTN, FAT1, CDKN2A, and MUC16. A high level of CD8⁺ T cells and high immune and stroma scores corresponded to a better survival probability in HNSCC.

Recurrent/Metastatic Head and Neck Squamous Cell Carcinoma in Older Patients: Are New Agents Bringing New Hope?

Head and neck cancer is a broad family of diseases, most of which are of squamous cell origin, affecting the epithelial mucosa lining the upper aerodigestive tract. They often recur or are progressive despite multimodality treatment approaches, resulting in a poor prognosis. Given the progressive aging of the global population, the probability to plan an active and eventually toxic treatment for an older patient, with either curative or palliative intent, can no longer be considered as an uncommon occurrence. A crucial point in offering a systemic treatment to older patients with head and neck squamous cell carcinoma is that they are underrepresented in randomised clinical trials, and evidence-based guidelines are lacking, while, from a clinical point of view, these patients may have varying grades of resilience to anticancer treatments due to differences in their health, social and/or economic status. Our aim is to draw attention to the older patient population suffering from recurrent and/or metastatic head and neck squamous cell carcinoma and to address some open questions, such as possible differences in epidemiology and biology compared with their younger counterparts; to highlight frailty and its components by discussing how to measure and use it to personalise treatment; to evaluate which outcomes should be best achieved in the older adult setting; finally, in the era of immunotherapy, to examine whether there are differences to be addressed when considering new treatments for older patients.

Differential Immunomodulatory Effects of Head and Neck Cancer-Derived Exosomes on B Cells in the Presence of ATP

Head and neck squamous cell carcinoma (HNSCC) is an aggressive malignancy. Tumor-derived exosomes (TEX) have immunoregulatory properties. Adenosine triphosphate (ATP) and its immunosuppressive precursor adenosine (ADO) have been found in cancerous tissue. We investigated the effect of TEX on B cells in the presence of ATP. TEX were isolated from human HNSCC cell line (PCI-13) cultures and co-cultured with peripheral blood B cells of healthy donors, with or without TEX in different concentrations and with or without a low (20 µM) or high (2000 µM) ATP dose. We were able to demonstrate that TEX inhibit B-cell proliferation. The addition of TEX to either ATP concentration showed a decreasing trend in CD39 expression on B cells in a dose-dependent manner. High ATP levels (2000 µM) increased apoptosis and necrosis, and analysis of apoptosis-associated proteins revealed dose-dependent effects of ATP, which were modified by TEX. Altogether, TEX exhibited dual immunomodulatory effects on B cells. TEX were immunosuppressive by inhibiting B-cell proliferation; they were immunostimulatory by downregulating CD39 expression. Furthermore, TEX were able to modulate the expression of pro- and anti-apoptotic proteins. In conclusion, our data indicate that TEX play an important, but complex, role in the tumor microenvironment.

Shared genetic and epigenetic changes link aging and cancer

Aging is a universal biological process that increases the risk of multiple diseases including cancer. Growing evidence shows that alterations in the genome and epigenome, driven by similar mechanisms, are found in both aged cells and cancer cells. In this review, we detail the genetic and epigenetic changes associated with normal aging and the mechanisms responsible for these changes. By highlighting genetic and epigenetic alterations in the context of tumorigenesis, cancer progression, and the aging tumor microenvironment, we examine the possible impacts of the normal aging process on malignant transformation. Finally, we examine the implications of age-related genetic and epigenetic alterations in both tumors and patients for the treatment of cancer.

Age-specific oncogenic pathways in head and neck squamous cell carcinoma - are elderly a different subcategory?

BACKGROUND

In recent clinical practice, an increasing number of elderly patients suffering from head and neck squamous cell carcinoma (HNSCC) of unknown pathophysiology is observed. The majority of HNSCC patients can roughly be divided into three subcategories. First, a small group of young patients who present with variants of genomic aberrations and inheritable diseases like Fanconi anaemia. Second, an increasing population of HPV-related HNSCCs that are regarded as genomic stable tumours with a more favourable prognosis. Though HPV-related tumours used to be more common among younger males, a notable rise in the elderly population is observed. The third subcategory, that of HPV-negative tumours, has been shown to be more heterogeneous with involvement of a variety of oncogenic pathways related to lifestyle factors like smoking and alcohol consumption, often seen in middle-aged males. Some of these pathways could be related to age, such as TP53 alterations, EGFR activation, apoptotic pathway alterations and field cancerization.

CONCLUSIONS

In this narrative review, we provide an overview of established and newly discovered age-specific pathophysiological mechanisms underlying HNSCC. We propose a fourth subcategory of patients with a suspected different pathophysiology: elderly (HPV-negative) HNSCC patients without a history of tobacco and alcohol consumption. In this subcategory, carcinogenesis seems to be a multi-step process based on genomic instability, immunosenescence, cell cycle disruption and telomere shortening. To conclude, we discuss suggestions for future research to fill the knowledge gap about age-dependent HNSCC carcinogenesis.

Germline variants in DNA repair genes are associated with young-onset head and neck cancer

The genetic predisposition to head and neck carcinomas (HNSCC) and how the known risk factors (papillomavirus infection, alcohol, and tobacco consumption) contribute to the early-onset disease are barely explored. Although HNSCC at early onset is rare, its frequency is increasing in recent years. Germline and somatic variants were assessed to build a comprehensive genetic influence pattern in HNSCC predisposition and patient outcome. Whole-exome sequencing was performed in 45 oral and oropharynx carcinomas paired with normal samples of young adults (≤49 years). We found FANCG, CDKN2A, and TPP germline variants previously associated with HNSCC risk. At least one germline variant in DNA repair pathway genes was detected in 67% of cases. Germline and somatic variants (including copy number variations) in FAT1 gene were identified in 9 patients (20%) and 12 tumors (30%), respectively. Somatic variants were found in HNSCC associated genes, such as TP53, CDKN2A, and PIK3CA. To date, 55 of 521 cases from the large cohort of TCGA presented < 49 years old. A comparison between the somatic alterations of TCGA-HNSCC at early onset and our dataset revealed strong similarities. Protein-protein interaction analysis between somatic and germline altered genes revealed a central role of TP53. Altogether, germline alterations in DNA repair genes potentially contribute to an increased risk of developing HNSCC at early-onset, while FAT1 could impact the prognosis.

A model of seven immune checkpoint-related genes predicting overall survival for head and neck squamous cell carcinoma

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is a heterogeneous disease characterized by different molecular subtypes with different prognosis and response to treatment. Therefore, the aim of this study was to construct reliable gene signatures based on immune checkpoint-related genes to distinguish between subgroups of patients with different risks.

METHODS

We obtained the HNSCC data from The Cancer Genome Atlas (TCGA) database and Gene Expression Omnibus (GEO) as a training set and the external validation set, respectively. First, differentially expressed immune checkpoint-related genes in tumor tissues and normal tissues were determined, and the potential functions of differential genes were explored through GO function annotation and KEGG pathway enrichment analysis. Using univariate Cox regression analysis, 20 immune checkpoint-related genes in HNSCC patients were significantly associated with overall survival (OS). Subsequently, seven genes were selected by multivariate Cox regression analysis to create a gene signature. Next, the stability of gene signatures was assessed using Kaplan-Meier curve, Time-dependent receiver operating characteristic (ROC) curve. Finally, we constructed a nomogram visualization modelled to facilitate subsequent clinical applications.

RESULTS

A total of 80 differentially expressed genes (DEGs) were obtained, the GO analysis of these DEGs indicated that they were significantly enriched in positive regulation of cell activation, T cell activation; the KEGG analysis results performed and showed that the DEGs were enriched in the MAPK signaling pathway, PI3K - Akt signaling pathway. 7 genes (PPP2R1B, MYD88, CD86, CD80, MAP2K1, TRIB3 and ICOS) were screened by univariate and multivariate Cox regression, and they were used to construct a prognostic model. In the TCGA and GEO datasets, Kaplan-Meier analysis indicated that patients in the high-risk group have a poor prognosis. The sensitivity and specificity evaluation of prognostic model for 1-, 3-, 5-year OS in TCGA were 0.644, 0.661 and 0.625, respectively; and in GSE41613 were 0.748, 0.719, and 0.727, respectively. The calibration chart curve showed that the nomogram has strong clinical performance in the prognosis prediction of HNSCC patients.

CONCLUSIONS

A novel immune checkpoint-related gene signature can effectively predict and stratify OS in HNSCC patients.

Cancer3D 2.0: interactive analysis of 3D patterns of cancer mutations in cancer subsets

Our knowledge of cancer genomics exploded in last several years, providing us with detailed knowledge of genetic alterations in almost all cancer types. Analysis of this data gave us new insights into molecular aspects of cancer, most important being the amazing diversity of molecular abnormalities in individual cancers. The most important question in cancer research today is how to classify this diversity to identify subtypes that are most relevant for treatment and outcome prediction for individual patients. The Cancer3D database at http://www.cancer3d.org gives an open and user-friendly way to analyze cancer missense mutations in the context of structures of proteins they are found in and in relation to patients’ clinical data. This approach allows users to find novel candidate driver regions for specific subgroups, that often cannot be found when similar analyses are done on the whole gene level and for large, diverse cohorts. Interactive interface allows user to visualize the distribution of mutations in subgroups defined by cancer type and stage, gender and age brackets, patient's ethnicity or vice versa find dominant cancer type, gender or age groups for specific three-dimensional mutation patterns.

Adenosine-producing regulatory B cells in head and neck cancer

Background

Multiple mechanisms of immunosuppression have been identified in the tumor microenvironment including regulatory B cells (B_reg). Recently, we have shown that B_reg suppress T cell function by production of adenosine (ADO). However, the autocrine effect of ADO on B cells and the role of B_reg in head and neck cancer remains unclear.

Methods

Blood (n = 42) and tumor tissue (n = 39) of head and neck cancer patients and healthy donors (n = 60) were analyzed by FACS. The effect of ADO on phenotype, intracellular signaling pathways, Ca²⁺ influx and ADO production was analyzed in B_reg and effector B cells (B_eff) by FACS, luminescence and mass spectrometry. The blockage of the ADO receptor A_2A was analyzed in a murine head and neck cancer model.

Results

ADO-producing B_reg were found in tumor tissue and peripheral blood. ADO inhibited the intracellular Bruton’s tyrosine kinase (BTK) and Ca²⁺ influx only in B_eff. The inhibition of BTK by ibrutinib mimicked the effect of ADO, and ibrutinib reduced the production of ADO by downregulation of CD39 in vitro. The inhibition of ADO receptor A_2A significantly reduced tumor mass and increased B cell infiltration, in vivo.

Conclusion

Our data demonstrate the presence of a novel ADO-producing B_reg population within the tumor microenvironment in mice and humans. A new model is proposed on how ADO-producing B_reg can influence the function of B_eff cells in healthy donors and cancer patients. Thus, the modulation of the ADO pathway in B cells may serve as a therapeutic approach for cancer patients.

Electronic supplementary material

The online version of this article (10.1007/s00262-020-02535-6) contains supplementary material, which is available to authorized users.

Age-related changes in T lymphocytes of patients with head and neck squamous cell carcinoma

Introduction

The number of aging cancer patients has increased continuously and will do so further in the future. The immune system of elderly people experiences critical changes over the time. Therefore, tumor-induced changes in the immune system are believed to differ in young and elderly cancer patients as well.

Methods

The effect of aging on the immune system was measured in peripheral blood lymphocytes (PBL) of healthy volunteers (n = 48, 21–84 yrs.) divided into three different age groups. Seventy years was set as a cut-off for defining subjects as elderly. Results were compared to two groups of adult cancer patients, which donated PBL and tumor infiltrating lymphocytes (TIL): young cancer patients (40–69 yrs.; blood: n = 13; TIL: n = 17) and elderly cancer patients (70–90 yrs.; blood: n = 20; TIL: n = 15) with head and neck squamous cell carcinoma (HNSCC). Frequencies and phenotypes of CD4⁺ and CD8⁺ T cells as well as regulatory T cells (T_reg) were assessed by flow cytometry.

Results

We observed lower frequencies of CD8⁺ cytotoxic T cells during aging in both groups. Frequencies of tumor infiltrating regulatory T cells were significantly higher than in the peripheral blood but showed a significant decline in older tumor patients. With increasing age, expression of immunosuppressive CD73 and CCR7 was lower and expression of PD1 elevated on peripheral T cells in healthy volunteers and tumor patients.

Conclusion

Immunosenescence takes place in healthy donors and cancer patients. Our results suggest that in elderly tumor patients, the immune system is impaired and the tumor-induced immune escape is less pronounced. The increased expression of PD1 implies the potential for effective immunotherapies in elderly, as treatment with checkpoint inhibitors could be more beneficial for elderly HNSCC patients.

Use of Programmed Death Receptor-1 and/or Programmed Death Ligand 1 Inhibitors for the Treatment of Brain Metastasis of Lung Cancer

The central nervous system (CNS) is regarded as an immune privileged environment; however, changes in the neuroimmunology paradigm have led to an increased interest in systematic immunotherapy in lung cancer therapy. The presence of the lymphatic system in the CNS as well as the physiological and biochemical changes in the blood–brain barrier in the tumor microenvironment suggests that immunocytes are fully capable of entering and exiting the CNS. Emerging clinical data suggest that inhibitors of programmed death receptor-1/programmed death ligand 1 (PD-1/PD-L1) can stimulate surrounding T cells and thus have antitumor effects in the CNS. For example, PD-1 antibody (pembrolizumab) monotherapy has displayed a 20–30% encephalic response rate in patients with brain metastases from malignant melanoma or non-small cell lung cancer. Combined application of nivolumab and ipilimumab anti-PD-1 and anti-cytotoxic T-lymphocyte-associated protein 4 showed an encephalic response rate of 55% in patients with brain metastases of melanoma. Further evidence is required to verify these response rates and identify the mechanisms of curative effects and drug tolerance. While regional treatments such as whole-brain radiosurgery, stereotactic radiosurgery, and brain surgery remain the mainstream, PD-1/PD-L1 inhibitors display potential decreased neurotoxic effects. To date, five drugs have been approved for use in patients with encephalic metastases of lung carcinoma: the anti-PD-1 drugs, pembrolizumab and nivolumab, and the anti-PD-L1 agents, atezolizumab, durvalumab, and avelumab. In recent years, clinical trials of inhibitors in combination with other drugs to treat brain metastasis have also emerged. This review summarizes the biological principles of PD-1/PD-L1 immunotherapy for brain metastasis of lung cancer, as well as ongoing clinical trials to explore unmet needs.

Somatic genome alterations in relation to age in lung adenocarcinoma

Lung adenocarcinoma (LUAD) is the most common cause of global cancer-related mortality and the major risk factor is smoking consumption. By analyzing 486 LUAD samples from The Cancer Genome Atlas, we detected a higher mutational burden among younger patients in the global cohort as well as in the TP53-mutated subcohort. The interaction effect of patient age and TP53 mutations significantly affected the mutational rate of younger TP53-mutated patients. Furthermore, we detected a significant enrichment of the smoking-related signature SI4 (SI4) among younger TP53-mutated patients, meanwhile the age-related Signature 1 (SI1) significantly increased in proportion to patient age. Although present and past smoking is reported in the TP53 wild-type patients, we observed a lower average number of somatic mutations, with no correlation with patient age. Overall, TP53 mutations were significantly higher in younger patients and mainly characterized by SI4 and Signature 24 (SI24). Therefore, TP53 seemed to acquire a particular sensitivity to smoking related C>A mutations in younger patients. We hypothesize that TP53 mutations at a younger age might be a crucial factor enhancing the sensitivity to smoking-related mutations leading to a burst of somatic alterations. The mutational profile of cancer cell might reflect the mutational processes operative in aging in a given tissue. Therefore, TP53-mutated and TP53 wild-type patient groups might represent phenotypes which endure aging-related mutational processes with different strength. Our study provides indications of age-dependent differences in mutational backgrounds that might be relevant for cancer prevention and age-adjusted treatment approaches.

Application of PD-1 Blockade in Cancer Immunotherapy

The programmed cell death protein 1 (PD-1) pathway has received considerable attention due to its role in eliciting the immune checkpoint response of T cells, resulting in tumor cells capable of evading immune surveillance and being highly refractory to conventional chemotherapy. Application of anti-PD-1/PD-L1 antibodies as checkpoint inhibitors is rapidly becoming a promising therapeutic approach in treating tumors, and some of them have successfully been commercialized in the past few years. However, not all patients show complete responses and adverse events have been noted, suggesting a better understanding of PD-1 pathway mediated immunosuppression is needed to predict patient response and improve treatment efficacy. Here, we review the progresses on the studies of the mechanistic role of PD-1 pathway in the tumor immune evasion, recent clinical development and commercialization of PD-1 pathway inhibitors, the toxicities associated with PD-1 blockade observed in clinical trials as well as how to improve therapeutic efficacy and safety of cancer immunotherapy.

Impaired Cytolytic Activity and Loss of Clonal Neoantigens in Elderly Patients With Lung Adenocarcinoma

INTRODUCTION

Whether the efficacy of programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) inhibitors declines with senescence remains controversial for lung adenocarcinoma (LUAD). Responsiveness to anti-PD-1/PD-L1 therapy is thought to rely on neoantigen exposure and immune elements in the tumor microenvironment. In this study, we explored the features of the tumor immune microenvironment in elderly patients with treatment-naïve LUAD.

METHODS

Transcriptome profiles and clinical characteristics of patients with LUAD were retrieved from The Cancer Genome Atlas as a discovery cohort. Immune cell infiltration (quantified by a single-sample gene set enrichment analysis), immunoregulatory molecule expression, and mutational patterns (from The Cancer Immunome Atlas) were compared between young and elderly patients. Immune cell infiltration was verified by immunohistochemistry using a validation cohort including 105 treatment-naïve patients with LUAD. A tissue microarray consisting of 120 LUAD patients was used in the immunohistochemistry validation.

RESULTS

Activated CD8⁺ T cell numbers increased slightly with age, but cytolytic molecules in T cells (granzyme B [GZMB], perforin 1 [PRF1], granzyme A [GZMA], granzyme M [GZMM], and granulysin [GNLY]) gradually declined. PD-L1 expression was not associated with age; however, a number of immunosuppressive elements beyond PD-L1 were upregulated in aging patients, including regulatory T cells and co-inhibitory molecules, for example, TIM-3, TIGIT, and HHLA2. Finally, senescence was accompanied by a loss of clonal neoantigens, which is believed to be correlated with responsiveness to immune checkpoint inhibitors.

CONCLUSIONS

Elderly patients were characterized by increased numbers of CD8⁺ T cells and impaired cytolytic molecule expression. The observed immune signature was also associated with a loss of clonal neoantigens and the accumulation of immunosuppressive elements. These findings show a unique immune microenvironment in senescence and support biomarker-guided candidate identification for anti-PD-1/PD-L1 therapeutic strategies for elderly patients with LUAD.

Somatic genome alterations in relation to age in lung squamous cell carcinoma

Lung squamous cell carcinoma (LUSC) is the most common cause of global cancer-related mortality and the major risk factors is smoking consumption. By analyzing ∼500 LUSC samples from The Cancer Genome Atlas, we detected a higher mutational burden as well as a higher level of methylation changes in younger patients. The SNPs mutational profiling showed enrichments of smoking-related signature 4 and defective DNA mismatch repair (MMR)-related signature 6 in younger patients, while the defective DNA MMR signature 26 was enriched among older patients. Furthermore, gene set enrichment analysis was performed in order to explore functional effect of somatic alterations in relation to patient age. Extracellular Matrix-Receptor Interaction, Nucleotide Excision Repair and Axon Guidance seem crucial disrupted pathways in younger patients. We hypothesize that a higher sensitivity to smoking-related damages and the enrichment of defective DNA MMR related mutations may contribute to the higher mutational burden of younger patients. The two distinct age-related defective DNA MMR signatures 6 and 26 might be crucial mutational patterns in LUSC tumorigenesis which may develop distinct phenotypes. Our study provides indications of age-dependent differences in mutational backgrounds (SNPs and CNVs) as well as epigenetic patterns that might be relevant for age adjusted treatment approaches.

Cancer Immunotherapy in Older Patients

Advancing age remains one of the most significant risk factors for cancer development. Changes in the immune system occur with aging, and likely play a role in the increased incidence of malignancy in older patients. With the advent of immune checkpoint inhibitors, and their use in a variety of malignancies, there has been an explosion of clinical trials evaluating their use. Unfortunately, these trials have not shown consistent results in elderly patients, nor have age-specific outcomes been consistently reported. Further evaluation of the efficacy and toxicity of these agents in the elderly is needed, as they are now in frequent clinical use. By investigating how age-related changes in the immune system occur and intersect with use of immune checkpoint inhibitors, their use can be optimized in a clear and safe manner. Further study of age-related changes in the immune system can also lead to effective combination immunotherapeutic approaches, maximizing the efficacy of immune checkpoint inhibitors across tumor types and across the age spectrum of cancer patients.

[B cells in head and neck oncology]

As immunotherapy is becoming increasingly important in the treatment of head and neck cancer, a fundamental understanding of the immunological relationships in the tumor microenvironment is required. The importance of tumor-infiltrating B cells (TIL-B) has been largely neglected so far. In the current literature, however, a significant influence of B cells on tumor growth is described, so that this cell population is now also perceived as a therapeutic target structure. Regulatory B cells (B_reg) represent a subset of B cells with immunosuppressive properties. In addition to the secretion of IL-10, B_reg can be defined by their ability to produce adenosine. Adenosine is known as an immunosuppressive messenger in the tumor microenvironment whose effect can be prevented by immunotherapeutic approaches. Understanding the tumor immunological relationships, including the different B‑cell functions, can help to effectively combine standard approaches including surgery or radiochemotherapy with immunotherapy. In the present article, recent findings on B cells and adenosine in head and neck cancer are described.

Searching for Clinically Relevant Biomarkers in Geriatric Oncology

Ageing, which is associated with a progressive decline and functional deterioration in multiple organ systems, is highly heterogeneous, both inter- and intraindividually. For this, tailored-made theranostics and optimum patient stratification become fundamental, when decision-making in elderly patients is considered. In particular, when cancer incidence and cancer-related mortality and morbidity are taken into account, elderly patient care is a public health concern. In this review, we focus on oncogeriatrics and highlight current opportunities and challenges with an emphasis on the unmet need of clinically relevant biomarkers in elderly cancer patients. We performed a literature search on PubMed and Scopus databases for articles published in English between 2000 and 2017 coupled to text mining and analysis. Considering the top insights, we derived from our literature analysis that information knowledge needs to turn into knowledge growth in oncogeriatrics towards clinically relevant biomarkers, cost-effective practices, updated educational schemes for health professionals (in particular, geriatricians and oncologists), and awareness of ethical issues. We conclude with an interdisciplinary call to omics, geriatricians, oncologists, informatics, and policy-makers communities that Big Data should be translated into decision-making in the clinic.

Oxidative Stress Gene Expression Profile Correlates with Cancer Patient Poor Prognosis: Identification of Crucial Pathways Might Select Novel Therapeutic Approaches

The role of altered redox status and high reactive oxygen species (ROS) is still controversial in cancer development and progression. Intracellular levels of ROS are elevated in cancer cells suggesting a role in cancer initiation and progression; on the contrary, ROS elevated levels may induce programmed cell death and have been associated with cancer suppression. Thus, it is crucial to consider the double-face of ROS, for novel therapeutic strategies targeting redox regulatory mechanisms. In this review, in order to derive cancer-type specific oxidative stress genes' profile and their potential prognostic role, we integrated a publicly available oxidative stress gene signature with patient survival data from the Cancer Genome Atlas database. Overall, we found several genes statistically significant associated with poor prognosis in the examined six tumor types. Among them, FoxM1 and thioredoxin reductase1 expression showed the same pattern in four out of six cancers, suggesting their specific critical role in cancer-related oxidative stress adaptation. Our analysis also unveiled an enriched cellular network, highlighting specific pathways, in which many genes are strictly correlated. Finally, we discussed novel findings on the correlation between oxidative stress and cancer stem cells in order to define those pathways to be prioritized in drug development.

CtBP2 is associated with angiogenesis and regulates the apoptosis of prostate cancer cells

Angiogenesis is associated with prostate cancer (PCa) development and progression. Aberrant expression of C-terminal binding protein (CtBP)2 has been observed in PCa, but whether its change in expression plays a significant role in angiogenesis has not been completely characterized. we attempted to integrate and analyze the genome-wide association study (GWAS) of follicle stimulating hormone receptor (FSHR) and CtBP2, the Cancer Genome Atlas (TCGA) data and CtBP2 binding data in CistromeMap (18) to explore the mechanism of CtBP2 in PCa, and performed pathway enrichment analysis. We revealed that the top 6 pathways were closely related with angiogenesis. We used siRNA and overexpression plasmids to silence and overexpress CtBP2 expression. Altered expression of CtBP2 affected the expression of VEGFA, FSHR, FHL2 and SMAD3 which are closely related with angiogenesis. In addition, silencing of CtBP2 markedly increased the apoptosis of PCa cells in vitro, and decreased the expression of IL-8, AT2R, CCND1 and MMP9 which are associated with cancer progression. These results highlight the association between CtBP2 and angiogenesis in PCa and indicate that CtBP2 may be a potential therapeutic target for PCa.