Posttranslational modifications of FOXO1 regulate epidermal growth factor receptor tyrosine kinase inhibitor resistance for non-small cell lung cancer cells

FOXO1, a tiny protein with intricate interactions: Promising therapeutic candidate in lung cancer

Nowadays, lung cancer is the most common cause of cancer-related deaths in both men and women globally. Despite the development of extremely efficient targeted agents, lung cancer progression and drug resistance remain serious clinical issues. Increasing knowledge of the molecular mechanisms underlying progression and drug resistance will enable the development of novel therapeutic methods. It has been revealed that transcription factors (TF) dysregulation, which results in considerable expression modifications of genes, is a generally prevalent phenomenon regarding human malignancies. The forkhead box O1 (FOXO1), a member of the forkhead transcription factor family with crucial roles in cell fate decisions, is suggested to play a pivotal role as a tumor suppressor in a variety of malignancies, especially in lung cancer. FOXO1 is involved in diverse cellular processes and also has clinical significance consisting of cell cycle arrest, apoptosis, DNA repair, oxidative stress, cancer prevention, treatment, and chemo/radioresistance. Based on the critical role of FOXO1, this transcription factor appears to be an appropriate target for future drug discovery in lung cancers. This review focused on the signaling pathways, and molecular mechanisms involved in FOXO1 regulation in lung cancer. We also discuss pharmacological compounds that are currently being administered for lung cancer treatment by affecting FOXO1 and also point out the essential role of FOXO1 in drug resistance. Future preclinical research should assess combination drug strategies to stimulate FOXO1 and its upstream regulators as potential strategies to treat resistant or advanced lung cancers.

Current Strategies for Treating NSCLC: From Biological Mechanisms to Clinical Treatment

The identification of specific epidermal growth factor receptor (EGFR)-activating mutations heralded a breakthrough in non-small-cell lung cancer (NSCLC) treatments, with the subsequent development of EGFR-tyrosine kinase inhibitor (TKIs) becoming the first-line therapy for patients harboring EGFR mutations. However, acquired resistance to EGFR-TKIs inevitably occurs in patients following initial TKI treatment, leading to disease progression. Various mechanisms are behind the acquired resistance, and mainly include (1) target gene modification, (2) alternative parallel pathway activation, (3) downstream pathway activation, and (4) histological/phenotypic transformation. Approaches to combat the acquired resistance have been investigated according to these mechanisms. Newer generations of TKIs have been developed to target the secondary/tertiary EGFR mutations in patients with acquired resistance. In addition, combination therapies have been developed as another promising strategy to overcome acquired resistance through the activation of other signaling pathways. Thus, in this review, we summarize the mechanisms for acquired resistance and focus on the potential corresponding therapeutic strategies for acquired resistance.

FOXO1 overexpression is correlated with poor prognosis in epithelial ovarian cancer

OBJECTIVE

To investigate FOXO1 expression in epithelial ovarian cancer (EOC), and to explore its correlation with clinicopathological parameters and prognosis of EOC.

METHODS

Two hundred and sixteen cases of paraffin-embedded EOC and 41 paratumor tissues from 2009 to 2017 that had been pathologically confirmed at the memorial hospital of Sun Yat-sen University were included in this study, and the expression of FOXO1 was performed by immunohistochemistry using a polyclonal antibody specific for FOXO1.

RESULTS

FOXO1 protein expression is associated with Recurrence free and overall survival in EOC patients; In addition, FOXO1 expression is associated with age, FIGO stage, intraperitoneal metastasis, intestinal metastasis, vital status, intraperitoneal recurrence and differentiation grade; Moreover, in a multivariate model FOXO1 overexpression was an independent predictor of poor survival in EOC.

CONCLUSION

FOXO1 may play a candidate oncogenic role in EOC, and FOXO1 is a useful independent prognostic marker in EOC, and it may provide a candidate target therapy in future.

Heart Failure in Type 2 Diabetes Mellitus

Patients with diabetes mellitus have >2× the risk for developing heart failure (HF; HF with reduced ejection fraction and HF with preserved ejection fraction). Cardiovascular outcomes, hospitalization, and prognosis are worse for patients with diabetes mellitus relative to those without. Beyond the structural and functional changes that characterize diabetic cardiomyopathy, a complex underlying, and interrelated pathophysiology exists. Despite the success of many commonly used antihyperglycemic therapies to lower hyperglycemia in type 2 diabetes mellitus the high prevalence of HF persists. This, therefore, raises the possibility that additional factors beyond glycemia might contribute to the increased HF risk in diabetes mellitus. This review summarizes the state of knowledge about the impact of existing antihyperglycemic therapies on HF and discusses potential mechanisms for beneficial or deleterious effects. Second, we review currently approved pharmacological therapies for HF and review evidence that addresses their efficacy in the context of diabetes mellitus. Dysregulation of many cellular mechanisms in multiple models of diabetic cardiomyopathy and in human hearts have been described. These include oxidative stress, inflammation, endoplasmic reticulum stress, aberrant insulin signaling, accumulation of advanced glycated end-products, altered autophagy, changes in myocardial substrate metabolism and mitochondrial bioenergetics, lipotoxicity, and altered signal transduction such as GRK (g-protein receptor kinase) signaling, renin angiotensin aldosterone signaling and β-2 adrenergic receptor signaling. These pathophysiological pathways might be amenable to pharmacological therapy to reduce the risk of HF in the context of type 2 diabetes mellitus. Successful targeting of these pathways could alter the prognosis and risk of HF beyond what is currently achieved using existing antihyperglycemic and HF therapeutics.

Molecular insights into cancer drug resistance from a proteomics perspective

INTRODUCTION

Resistance to chemotherapy and development of specific and effective molecular targeted therapies are major obstacles facing current cancer treatment. Comparative proteomic approaches have been employed for the discovery of putative biomarkers associated with cancer drug resistance and have yielded a number of candidate proteins, showing great promise for both novel drug target identification and personalized medicine for the treatment of drug-resistant cancer. Areas covered: Herein, we review the recent advances and challenges in proteomics studies on cancer drug resistance with an emphasis on biomarker discovery, as well as understanding the interconnectivity of proteins in disease-related signaling pathways. In addition, we highlight the critical role that post-translational modifications (PTMs) play in the mechanisms of cancer drug resistance. Expert opinion: Revealing changes in proteome profiles and the role of PTMs in drug-resistant cancer is key to deciphering the mechanisms of treatment resistance. With the development of sensitive and specific mass spectrometry (MS)-based proteomics and related technologies, it is now possible to investigate in depth potential biomarkers and the molecular mechanisms of cancer drug resistance, assisting the development of individualized therapeutic strategies for cancer patients.

Efficacy of Azatyrosine-Phenylbutyric Hydroxamides, a Histone Deacetylase Inhibitor, on Chemotherapy-Induced Gastrointestinal Mucositis

Gastrointestinal mucositis is a serious side effect of chemotherapy. Currently, no effective treatment exists for chemotherapy-induced mucositis, prompting the need to develop an anti-mucositis agent for use in clinics. The present study investigated whether azatyrosine-PBHA (AzP), a histone deacetylase inhibitor, has a therapeutic effect on intestinal mucosa. The results indicated that AzP did not affect the proliferation and viability of cancer cells, outcomes that are achieved by suberoylanilide hydroxamic acid (SAHA). However, AzP could decrease production of the inflammatory mediators interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), and tumor-necrosis factor-α (TNF-α). In vivo histopathological assessment showed that AzP reduced cisplatin-induced injury to the jejunum villi and triggered weight loss in the C57BL/6 mice. Immunohistochemistry (IHC) results demonstrated that mice treated with AzP also recovered from cisplatin-induced injury to the intestinal mucosa. Mechanistic in vitro study using DAVID/KEGG enrichment analysis of microarray data and confirmation by a Western blot indicated the influence of AzP on the MEK/ERK and AKT-dependent pathway. In conclusion, the study demonstrated that AzP might regulate the MEK/ERK MAPK signaling pathway to attenuate MCP-1, TNF-α, and IL-6 production and provide opportunities for the development of new anti-inflammatory drugs targeting mucositis.

The Dominant Role of Forkhead Box Proteins in Cancer

Forkhead box (FOX) proteins are multifaceted transcription factors that are significantly implicated in cancer, with various critical roles in biological processes. Herein, we provide an overview of several key members of the FOXA, FOXC, FOXM1, FOXO and FOXP subfamilies. Important pathophysiological processes of FOX transcription factors at multiple levels in a context-dependent manner are discussed. We also specifically summarize some major aspects of FOX transcription factors in association with cancer research such as drug resistance, tumor growth, genomic alterations or drivers of initiation. Finally, we suggest that targeting FOX proteins may be a potential therapeutic strategy to combat cancer.

Estimates of linkage disequilibrium and effective population sizes in Chinese Merino (Xinjiang type) sheep by genome-wide SNPs

Knowledge of linkage disequilibrium (LD) is important for effective genome-wide association studies and accurate genomic prediction. Chinese Merino (Xinjiang type) is well-known fine wool sheep breed. However, the extent of LD across the genome remains unexplored. In this study, we calculated autosomal LD based on genome-wide SNPs of 635 Chinese Merino (Xinjiang type) sheep by Illumina Ovine SNP50 BeadChip. A moderate level of LD (r² ≥ 0.25) across the whole genome was observed at short distances of 0–10 kb. Further, the ancestral effective population size (N_e) was analyzed by extent of LD and found that N_e increased with the increase of generations and declined rapidly within the most recent 50 generations, which is consistent with the history of Chinese Merino sheep breeding, initiated in 1971. We also noted that even when the effective population size was estimated across different single chromosomes, N_e only ranged from 140.36 to 183.33 at five generations in the past, exhibiting a rapid decrease compared with that at ten generations in the past. These results indicated that the genetic diversity in Chinese Merino sheep recently decreased and proper protective measures should be taken to maintain the diversity. Our datasets provided essential genetic information to track molecular variations which potentially contribute to phenotypic variation in Chinese Merino sheep.

A global perspective on FOXO1 in lipid metabolism and lipid-related diseases

Lipid metabolism is a complex physiological process that is involved in nutrient adjustment, hormone regulation, and homeostasis. An unhealthy lifestyle and chronic nutrient overload can cause lipid metabolism disorders, which may lead to serious lipid-related diseases, including obesity, non-alcoholic fatty liver disease (NAFLD), and type 2 diabetes mellitus (T2DM). Therefore, tools for preventing dysfunctional lipid metabolism are urgently needed. The transcription factor forkhead box protein O1 (FOXO1) is involved in lipid metabolism and plays a critical role in the development of lipid-related diseases. In this review, we provide a global perspective on the role of FOXO1 in lipid metabolism and lipid-related diseases. The information included here may be useful for the design of future studies and advancing investigations of FOXO1 as a therapeutic target.

FOXOs in the impaired heart: New therapeutic targets for cardiac diseases

Cardiac diseases have a high morbidity and mortality and affect the global population. Based on recent accumulating evidence, Forkhead box O (FOXOs) play important roles in cardiac diseases. Therefore, a summary of the current literature on the molecular mechanisms and roles of FOXOs in the heart will provide valuable information. In this review, we first briefly introduce the molecular features of FOXOs. Then, we discuss the regulation and cardiac actions of the FOXO pathways. Based on this background, we expand our discussion to the roles of FOXOs in several major cardiac diseases, such as ischemic cardiac diseases, diabetic cardiomyopathy and myocardial hypertrophy. Then, we describe some methodological problems associated with the FOXO gene-modified animal models. Finally, we discuss potential future directions. The information reviewed here may be significant for the design of future studies and may increase the potential of FOXOs as therapeutic targets.