Hypoxia-induced autophagy drives colorectal cancer initiation and progression by activating the PRKC/PKC-EZR (ezrin) pathway

Cancer stem cell populations are resistant to 5-aminolevulinic acid-photodynamic therapy (5-ALA-PDT)

Photodynamic therapy (PDT) is a minimally invasive treatment approved for many types of cancers. PDT involves the administration of photoactive substances called photosensitizers (PS) that selectively accumulate in cancer cells and are subsequently excited/activated by irradiation with light at wavelengths of optimal absorbance. Activated PS leads to the generation of singlet oxygen and other reactive oxygen species (ROS), promoting cancer cell death. 5-aminolevulinic acid (5-ALA) is a naturally occurring PS precursor, which is metabolically converted to the PS, protoporphyrin IX (PPIX). Although 5-ALA-PDT is effective at killing cancer cells, in prior studies conducted by our group we normally observed in in vitro experiments that approximately 5-10% of cells survive 5-ALA-PDT, which served as an impetus for further investigation. Identifying the mechanisms of resistance to 5-ALA-PDT-mediated cell death is important to prevent tumor recurrence following 5-ALA-PDT. Previously, we reported that oncogenic activation of Ras/MEK promotes PPIX efflux and reduces cellular sensitivity to 5-ALA-PDT through increased expression of ABCB1 transporter. As cancer stem cells (CSCs) are known to drive resistance to other cancer treatments and have high efflux of chemotherapeutic agents via ABC-family transporters, we hypothesize that CSCs underlie 5-ALA-PDT resistance. In this study, we determined (1) if CSCs are resistant to 5-ALA-PDT and (2) if CSCs play roles in establishing resistant populations of 5-ALA-PDT. When we compared CSC populations before and after 5-ALA-PDT, we found that CSCs were less susceptible to 5-ALA-PDT. Moreover, we found that the CSC population was enriched in 5-ALA-PDT-resistant cell lines compared to the parental cell line. Our results indicate that CSCs are not sensitive to 5-ALA-PDT, which may contribute to establishment of 5-ALA-PDT resistance.

Hypoxia-Associated GPNMB+ Macrophages Promote Malignant Progression of Colorectal Cancer and Its Related Risk Signature Are Powerful Predictive Tool for the Treatment of Colorectal Cancer Patients

Colorectal cancer (CRC) is a highly malignant tumor with hypoxia being a crucial feature during its progression. This study utilized multiple independent CRC cohorts for bioinformatics analysis and in vitro experiments to investigate the role of hypoxia-related subgroups in CRC. Machine learning was employed to construct risk features associated with this subgroup and further explore its therapeutic value in CRC. The study identified the GPNMB+ Macrophage (GPNMB+ Macr) subgroup as most relevant to hypoxia. GPNMB+ Macr showed significantly higher infiltration in tumor tissues compared to non-tumor tissues, increasing with CRC stage. High infiltration of GPNMB+ Macr was associated with poor prognosis in terms of overall and recurrence-free survival in CRC patients. GPNMB+ Macrophages exhibit M2-like characteristics and have the ability to promote 5-FU resistance, proliferation, and metastasis of CRC cells. The study developed the Hypoxia-Related Macrophage Risk Score (HMRS), which not only served as an independent prognostic factor for CRC patients but also demonstrated robust prognostic performance compared to 84 previously published prognostic features. Patients with low HMRS were sensitive to fluorouracil, oxaliplatin (FOLFOX), and anti-PD-1 immunotherapy, while those with high HMRS showed resistance. Additionally, HMRS was identified as an independent prognostic factor in other digestive tract tumors (hepatocellular carcinoma, pancreatic cancer, esophageal cancer, and gastric cancer), indicating potential extrapolation to other tumor types. In conclusion, GPNMB+ Macr promotes the malignant progression of CRC, and HMRS serves as a powerful predictive tool for prognosis, chemotherapy, and immunotherapy in CRC patients, aiding in improving the quality of survival.

Unraveling the role of the P2X7 receptor in cancer radioresistance: Molecular insights and therapeutic implications

The P2X7 receptor, a key player in purinergic signaling, is a crucial factor in modulating the response of cancer cells to radiotherapy. The aim of this study was to elucidate the molecular mechanisms by which P2X7 receptor activation contributes to radioresistance in different cancer types. P2X7 receptor signaling influences cellular processes such as DNA damage repair and inflammatory responses, thereby improving tumor survival after radiation exposure. Activation of the P2X7 receptor leads to changes in the tumor microenvironment and promotes an adaptive response that enables cancer cells to resist therapeutic interventions. Therefore, targeting the P2X7 receptor could represent a new therapeutic strategy against cancer. By linking molecular insights with therapeutic implications, this research highlights the P2X7 receptor as a promising target for overcoming radioresistance in cancer therapy and paves the way for novel combination approaches that could significantly improve patient outcomes.

FOXS1, frequently inactivated by promoter methylation, inhibited colorectal cancer cell growth by promoting TGFBI degradation through autophagy-lysosome pathway

INTRODUCTION

Tumor suppressor gene (TSG) inactivation by epigenetic modifications contributes to the carcinogenesis and progression of colorectal cancer (CRC). Expression profiling and CpG methylomics revealed that a forkhead-box transcriptional factor, FOXS1, is downregulated and methylated in CRC.

OBJECTIVES

To assess the biological functions and underlying mechanisms of FOXS1 in colorectal cancer.

METHODS

Public databases, semi-quantitative RT-PCR, immunohistochemistry, MSP, and BGS were used to analyze FOXS1 expression and promoter methylation in CRC. Stable FOXS1-overexpressing or knockdown cell lines were established. Cell growth, colony formation, flow cytometry, GFP-LC3 puncta detection, Ad-mCherry-GFP-LC3B, qPCR, in vivo subcutaneous tumor model, RNA-seq, western blotting, immunofluorescence, Co-IP assays, and protein stability analysis were performed to investigate the underlying molecular mechanisms of FOXS1.

RESULTS

In CRC, FOXS1 was frequently downregulated due to promoter CpG methylation, acting as an independent prognostic marker. Moreover, FOXS1 exerts inhibitory effects on the growth of CRC cells in vitro and in vivo, while concurrently promoting CRC cell autophagy. Intriguingly, we found that FOXS1 interacted with transforming growth factor beta induced (TGFBI) and FOXS1 promoted TGFBI degradation through the autophagy-lysosome pathway rather than the ubiquitin-proteasome system. FOXS1 was also found to facilitate the interaction between TGFBI and lysosomal associated membrane protein 2A (LAMP2A), leading to the translocation of TGFBI into lysosomes for degradation. Additionally, FOXS1 regulates AKT phosphorylation and FOXO3a nuclear translocation, promoting the transcription of autophagy-related genes downstream of FOXO3a. Restoration of TGFBI expression reversed the suppressive effect exerted by FOXS1 on the growth of colorectal cancer cells.

CONCLUSION

FOXS1 functions as a tumor suppressor that is methylated in CRC and promotes the lysosomal degradation of TGFBI, regulates cell growth and promotes autophagy in CRC through the TGFBI/AKT/FOXO3a signaling pathway. These findings indicate that FOXS1 exhibits potential as a promising biomarker and therapeutic target for colorectal cancer.

Hypoxia Affects Mitochondrial Stress and Facilitates Tumor Metastasis of Colorectal Cancer Through Slug SUMOylation

BACKGROUND

Colorectal cancer (CRC) is a malignant tumor. Slug has been found to display a key role in diversified cancers, but its relevant regulatory mechanisms in CRC development are not fully explored.

OBJECTIVE

Hence, exploring the function and regulatory mechanisms of Slug is critical for the treatment of CRC.

METHODS

Protein expressions of Slug, N-cadherin, E-cadherin, Snail, HIF-1α, SUMO- 1, Drp1, Opa1, Mfn1/2, PGC-1α, NRF1, and TFAM were measured through western blot. To evaluate the protein expression of Slug and SUMO-1, an immunofluorescence assay was used. Cell migration ability was tested through transwell assay. The SUMOylation of Slug was examined through CO-IP assay.

RESULTS

Slug displayed higher expression and facilitated tumor metastasis in CRC. In addition, hypoxia treatment was discovered to upregulate HIF-1α, Slug, and SUMO-1 levels, as well as induce Slug SUMOylation. Slug SUMOylation markedly affected mitochondrial biosynthesis, fusion, and mitogen-related protein expression levels to trigger mitochondrial stress. Additionally, the induced mitochondrial stress by hypoxia could be rescued by Slug inhibition and TAK-981 treatment.

CONCLUSION

Our study expounded that hypoxia affects mitochondrial stress and facilitates tumor metastasis of CRC through Slug SUMOylation.

Navigating therapeutic prospects by modulating autophagy in colorectal cancer

Colorectal cancer (CRC) remains a leading cause of death globally despite the improvements in cancer treatment. Autophagy is an evolutionarily conserved lysosomal-dependent degradation pathway that is critical in maintaining cellular homeostasis. However, in cancer, autophagy may have conflicting functions in preventing early tumour formation versus the maintenance of advanced-stage tumours. Defective autophagy has a broad and dynamic effect not just on cancer cells, but also on the tumour microenvironment which influences tumour progression and response to treatment. To add to the layer of complexity, somatic mutations in CRC including tumour protein p53 (TP53), v-raf murine sarcoma viral oncogene homolog B1 (BRAF), Kirsten rat sarcoma viral oncogene homolog (KRAS), and phosphatase and tensin homolog (PTEN) can render chemoresistance by promoting a pro-survival advantage through autophagy. Recent studies have also reported autophagy-related cell deaths that are distinct from classical autophagy by employing parts of the autophagic machinery, which impacts strategies for autophagy regulation in cancer therapy. This review discusses the molecular processes of autophagy in the evolution of CRC and its role in the tumour microenvironment, as well as prospective therapeutic methods based on autophagy suppression or promotion. It also highlights clinical trials using autophagy modulators for treating CRC, underscoring the importance of autophagy regulation in CRC therapy.

Super-Enhancer-Driven Syndecan-4 Regulates Intercellular Communication in Hypoxic Pulmonary Hypertension

BACKGROUND

Unveiling pro-proliferation genes involved in crosstalk between pulmonary artery endothelial cells and pulmonary artery smooth muscle cells (PASMCs) are important to improving the therapeutic outcome of pulmonary hypertension (PH). Although growing studies have shown that super-enhancers (SEs) play a pivotal role in pathological and physiological processes, the SE-associated genes in PH and their impact on PASMC proliferation remain largely unexplored.

METHODS AND RESULTS

We used serotype 5 adenovirus-associated virus to interfere with syndecan-4 and constructed an SU5416 combined with hypoxia-PH model. Chromatin immunoprecipitation sequencing analysis, chromatin immunoprecipitation quantitative polymerase chain reaction, and bioinformatics were used to confirm early growth response 1 was involved in regulating syndecan-4-associated SE in PASMCs. The effects of syndecan-4 and its underlying mechanisms were subsequently elucidated using Western blot, coimmunoprecipitation, and cell coculture assays. Herein, we identified a novel SE-associated gene, syndecan-4, in hypoxia-exposed PASMCs. Syndecan-4 was transcriptionally driven by early growth response 1 via an SE and was significantly overexpressed in hypoxic PASMCs and plasma from patients with PH. Mechanism studies revealed that syndecan-4 induces PASMC proliferation by interacting and regulating protein kinase C α ubiquitination. In addition, syndecan-4 was enriched in exosomes secreted from hypoxic PASMCs, which subsequently transported and led to pulmonary artery endothelial cell dysfunction. Syndecan-4 inhibition in hypoxia by serotype 5 adenovirus-associated virus treatment attenuated the pulmonary artery remodeling and development of PH in vivo.

CONCLUSIONS

Taken together, our results demonstrate that an SE-driven syndecan-4 modulates crosstalk of PASMCs and pulmonary artery endothelial cells and promotes vascular remodeling via the protein kinase C α and exosome pathway, thus providing potential targets for the early diagnosis and treatment of hypoxic PH.

Hypoxia-adenosinergic regulation of B cell responses

Hypoxic microenvironments induce widespread metabolic changes that have been shown to be critical in regulating innate and adaptive immune responses. Hypoxia-induced changes include the generation of extracellular adenosine followed by subsequent signaling through adenosine receptors on immune cells. This evolutionarily conserved "hypoxia-adenosinergic" pathway of hypoxia → extracellular adenosine → adenosine receptor signaling has been shown to be critical in limiting and redirecting T cell responses including in tumor microenvironments and the gut mucosa. However, the question of whether hypoxic microenvironments are involved in the development of B cell responses has remained unexplored until recently. The discovery that germinal centers (GC), the anatomic site in which B cells undergo secondary diversification and affinity maturation, develop a hypoxic microenvironment has sparked new interest in how this evolutionarily conserved pathway affects antibody responses. In this review we will summarize what is known about hypoxia-adenosinergic microenvironments in lymphocyte development and ongoing immune responses. Specific focus will be placed on new developments regarding the role of the hypoxia-adenosinergic pathway in regulating GC development and humoral immunity.

Interconnection of CD133 Stem Cell Marker with Autophagy and Apoptosis in Colorectal Cancer

CD133 protein expression is observable in differentiated cells, stem cells, and progenitor cells within normal tissues, as well as in tumor tissues, including colorectal cancer cells. The CD133 protein is the predominant cell surface marker utilized to detect cancer cells exhibiting stem cell-like characteristics. CD133 alters common abnormal processes in colorectal cancer, such as the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) and Wnt/β-catenin pathways. Autophagy is a cellular self-digestion mechanism that preserves the intracellular milieu and plays a dual regulatory role in cancer. In cancer cells, apoptosis is a critical cell death mechanism that can impede cancer progression. CD133 can modulate autophagy and apoptosis in colorectal cancer cells via several signaling pathways; hence, it is involved in the regulation of these intricate processes. This can be an explanation for why CD133 expression is associated with enhanced cellular self-renewal, migration, invasion, and survival under stress conditions in colorectal cancer. The purpose of this review article is to explain the complex relationship between the CD133 protein, apoptosis, and autophagy. We also want to highlight the possible ways that CD133-mediated autophagy may affect the apoptosis of colorectal cancer cells. Targeting the aforementioned mechanisms may have a significant therapeutic role in eliminating CD133-positive stem cell-phenotype colorectal cancer cells, which can be responsible for tumor recurrence.

Understanding the autophagic functions in cancer stem cell maintenance and therapy resistance

Complex tumour ecosystem comprising tumour cells and its associated tumour microenvironment (TME) constantly influence the tumoural behaviour and ultimately impact therapy failure, disease progression, recurrence and poor overall survival of patients. Crosstalk between tumour cells and TME amplifies the complexity by creating metabolic changes such as hypoxic environment and nutrient fluctuations. These changes in TME initiate stem cell-like programmes in cancer cells, contribute to tumoural heterogeneity and increase tumour robustness. Recent studies demonstrate the multifaceted role of autophagy in promoting fibroblast production, stemness, cancer cell survival during longer periods of dormancy, eventual growth of metastatic disease and disease resistance. Recent ongoing studies examine autophagy/mitophagy as a powerful survival strategy in response to environmental stress including nutrient deprivation, hypoxia and environmental stress in TME. It prevents irreversible senescence, promotes dormant stem-like state, induces epithelial-mesenchymal transition and increases migratory and invasive potential of tumour cells. The present review discusses various theories and mechanisms behind the autophagy-dependent induction of cancer stem cell (CSC) phenotype. Given the role of autophagic functions in CSC aggressiveness and therapeutic resistance, various mechanisms and studies based on suppressing cellular plasticity by blocking autophagy as a powerful therapeutic strategy to kill tumour cells are discussed.

Nano-vibration exciter: Hypoxia-inducible factor 1 signaling pathway-mediated extracellular vesicles as bioactive glass substitutes for bone regeneration

Bioactive glasses (BG) play a vital role in angiogenesis and osteogenesis through releasing functional ions. However, the rapid ion release in the early stage will cause excessive accumulation of metal ions, which in turn leads to obvious cytotoxicity, long-term inflammation, and bone repair failure. Inspired by the vibration exciter, small extracellular vesicles (sEVs) obtained by treating mesenchymal stem cells with copper-doped bioactive glass (CuBG-sEVs), is prepared as a nano-vibration exciter. The nano-vibration exciter can convert the ion signals of CuBG into biochemical factor signals through hypoxia-inducible factor 1 (HIF-1) signaling pathway and its activated autophagy, so as to better exert the osteogenic activity of BG. The results showed that CuBG extracts could significantly improve the enrichment of key miRNAs and increase the yield of CuBG-sEVs by activating HIF-1 signaling pathway and its activated autophagy. Cell experiments showed that CuBG-sEVs are favor to cell recruitment, vascularization and osteogenesis as the enrichment of key miRNAs. The animal experiments results showed that CuBG-sEVs stimulated angiogenesis mediated by CD31 and promoted bone regeneration by activating signaling pathways related to osteogenesis. These findings underscored the significant potential of sEVs as alternative strategies to better roles of BG.

Heterogeneity of tumor microenvironment cell groups in inflammatory and adenomatous polyposis coli mutant colorectal cancer based on single cell sequencing

Background

The prognosis of colorectal cancer (CRC) is known to vary across different etiologies. Inflammatory bowel disease (IBD) is often identified as a factor contributing to poorer outcomes. However, the mechanisms that link IBD to a worse CRC prognosis remain to be elucidated. We aim to reveal the complex tumor microenvironment of inflammatory CRC and provide a weak theoretical basis for the treatment of different subtypes of CRC.

Methods

We conducted a bioinformatics analysis using single-cell RNA sequencing (scRNA-seq) data from 8,494 individual CRC cells derived from azoxymethane (AOM)/dextran sodium sulfate (DSS) and adenomatous polyposis coli (APC) mutant datasets. The expression of implicated genes in both tumor and adjacent normal tissues was examined via immunohistochemistry and immunofluorescence.

Results

CRC from AOM/DSS treatment contained fewer immune cells relative to APC-mutant CRC. However, a macrophage subcluster enriched for inflammatory factors was more prevalent in AOM/DSS datasets. This subcluster exhibited elevated expression of APOE and BNIP3. Immunofluorescence and immunohistochemistry of patient samples confirmed that the expression of APOE and BNIP3 was higher in adjacent normal tissues compared to tumors.

Conclusions

Our findings shed light on the heterogeneous microenvironments in IBD and APC-mutant CRC. Furthermore, we identify APOE as a potential biomarker for CRC recurrence.

Autophagy-related lncRNAs and exosomal lncRNAs in colorectal cancer: focusing on lncRNA-targeted strategies

Autophagy is a cellular process that involves the degradation and recycling of cellular components, including damaged proteins and organelles. It is an important mechanism for maintaining cellular homeostasis and has been implicated in various diseases, including cancer. Long non-coding RNAs (lncRNAs) are a class of RNA molecules that do not code for proteins but instead play regulatory roles in gene expression. Emerging evidence suggests that lncRNAs can influence autophagy and contribute to the development and progression of colorectal cancer (CRC). Several lncRNAs have been identified as key players in modulating autophagy in CRC. The dysregulation of autophagy and non-coding RNAs (ncRNAs) in CRC suggests a complex interplay between these two factors in the pathogenesis of the disease. Modulating autophagy may sensitize cancer cells to existing therapies or improve the efficacy of new treatment approaches. Additionally, targeting specific lncRNAs involved in autophagy regulation could potentially be used as a therapeutic intervention to inhibit tumor growth, metastasis, and overcome drug resistance in CRC. In this review, a thorough overview is presented, encompassing the functions and underlying mechanisms of autophagy-related lncRNAs in a range of critical areas within tumor biology. These include cell proliferation, apoptosis, migration, invasion, drug resistance, angiogenesis, and radiation resistance.

Extracellular matrix production and oxygen diffusion regulate chemotherapeutic response in osteosarcoma spheroids

BACKGROUND

Osteosarcoma (OS) survival rates and outcome have not improved in 50 years since the advent of modern chemotherapeutics. Thus, there is a critical need for an improved understanding of the tumor microenvironment to identify better therapies. Extracellular matrix (ECM) deposition and hypoxia are known to abrogate the efficacy of various chemical and cell-based therapeutics. Here, we aim to mechanistically investigate the combinatorial effects of hypoxia and matrix deposition with the use of OS spheroids.

METHODS

We use two murine OS cell lines with differential metastatic potential to form spheroids. We form spheroids of two sizes, use ascorbate-2-phosphate supplementation to enhance ECM deposition, and study cell response under standard (21% O2) and physiologic (5% O2) oxygen tensions. Finally, we examine chemotherapeutic responses to doxorubicin treatment.

RESULTS

ECM production and oxygen tension are key determinants of spheroid size through cell organization based on nutrient and oxygen distribution. Interestingly, highly metastatic OS is more susceptible to chemotherapeutics compared to less metastatic OS when matrix production increases. Together, these data suggest that dynamic interactions between ECM production and oxygen diffusion may result in distinct chemotherapeutic responses despite inherent tumor aggressiveness.

CONCLUSION

This work establishes OS spheroids as a valuable tool for early OS tumor formation investigation and holds potential for novel therapeutic target and prognostic indicator discovery.

Regulatory feedback loop between circ-EIF4A3 and EIF4A3 Enhances autophagy and growth in colorectal cancer cells

Recent studies indicate that circular RNAs (circRNAs) are crucial in the progression of colorectal cancer (CRC). Eukaryotic translation initiation factor 4A3 (EIF4A3) has been identified as a promoter of circRNA production. The biological roles and mechanisms of EIF4A3-derived circRNA (circEIF4A3) in CRC cell autophagy remain poorly understood. This study explores the effects of circEIF4A3 on CRC cell growth and autophagy, aiming to elucidate the underlying molecular mechanisms. We discovered that EIF4A3 and circEIF4A3 synergistically enhance CRC cell growth. CircEIF4A3 sequesters miR-3126-5p, consequently upregulating EIF4A3. Further, circEIF4A3 increases EIF4A3 expression, which promotes autophagy by stabilizing ATG5 mRNA and enhances ATG7 protein stability through the stabilization of USP14 mRNA, a deubiquitinating enzyme. Upregulation of ATG5 and ATG7 counteracts the growth-inhibitory effects of EIF4A3 knockdown on CRC cells. Moreover, our findings demonstrate that EIF4A3 induces the formation of circEIF4A3 in CRC cells. In conclusion, a positive feedback loop between circEIF4A3 and EIF4A3 supports CRC cell growth by facilitating autophagy.

Potentially functional variants of ERRFI1 in hypoxia-related genes predict survival of non-small cell lung cancer patients

BACKGROUND

Hypoxia is often involved in tumor microenvironment, and the hypoxia-induced signaling pathways play a key role in aggressive cancer phenotypes, including angiogenesis, immune evasion, and therapy resistance. However, it is unknown what role genetic variants in the hypoxia-related genes play in survival of patients with non-small cell lung cancer (NSCLC).

METHODS

We evaluated the associations between 16,092 single-nucleotide polymorphisms (SNPs) in 182 hypoxia-related genes and survival outcomes of NSCLC patients. Data from the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial were used as the discovery dataset, and the Harvard Lung Cancer Susceptibility (HLCS) Study served as the replication dataset. We also performed additional linkage disequilibrium analysis and a stepwise multivariable Cox proportional hazards regression analysis in the PLCO dataset.

RESULTS

An independent SNP, ERRFI1 rs28624 A > C, was identified with an adjusted hazards ratio (HR) of 1.31 (95% CI = 1.14-1.51, p = 0.0001) for overall survival (OS). In further analyses, unfavorable genotypes AC and CC, compared with the AA genotype, were associated a worse OS (HR = 1.20, 95% CI = 1.03-1.39, p = 0.014) and disease-specific survival (HR = 1.21, 95% CI = 1.04-1.42, p = 0.016). Further expression quantitative trait loci analysis indicated that ERRFI1 rs28624C genotypes were significantly associated with higher ERRFI1 mRNA expression levels in the whole blood. Additional analysis showed that high ERRFI1 mRNA expression levels were associated with a worse OS in patients with lung adenocarcinoma.

CONCLUSION

Our findings suggest that genetic variants in the hypoxia-related gene ERRFI1 may modulate NSCLC survival, potentially through their effect on the gene expression.

Berberine mitigates diclofenac-induced intestinal mucosal mechanical barrier dysfunction through the restoration of autophagy by inhibiting exosome-mediated lncRNA H19

Small intestine damage caused by diclofenac is called diclofenac enteropathy. Berberine (BBR), a class of isoquinoline alkaloids derived from Berberis vulgaris and Phellodendron amurense, is widely used in intestinal diseases. The present study evaluated the protective effect of BBR on the intestinal mucosal mechanical barrier in diclofenac enteropathy and its possible action mechanism. The in vitro animal experiment revealed that BBR downregulated the expression of long non-coding RNA H19 (lncRNA H19) in the small intestine and exosomes. In the co-culture experiment involving exosomes and intestinal epithelial cell-6 (IEC-6) cells, the results of qRT-PCR, western blotting, and immunofluorescence assays demonstrated that the elevated expression of lncRNA H19 in the small intestine, conveyed via exosomes derived from the diclofenac group, suppressed the expression levels of autophagy-associated protein 5 (Atg 5) and light chain 3 (LC 3), as well as and the tight junction (TJ) proteins zonula occludens-1 (ZO-1), claudin-1, and occluding, relative to the control group. BBR treatment attenuated exosomal lncRNA H19 levels, upregulated the expression of Atg5 and LC3 expression, enhanced TJ protein expression, and increased the light chain 3 (LC3)-II/LC3-I ratio. These findings significantly elucidated that BBR promoted the restoration of autophagy in IECs by inhibiting exosomal lncRNA H19, thereby mitigating the impairment of the intestinal mucosal mechanical barrier function in diclofenac enteropathy. The process involving exosomal lncRNA H19 regulating autophagy, thereby affecting the intestinal mucosal mechanical barrier, offers a novel perspective for the application of BBR in the treatment of diclofenac enteropathy.

Liensinine sensitizes colorectal cancer cells to oxaliplatin by targeting HIF-1α to inhibit autophagy

BACKGROUND

Oxaliplatin is the most common chemotherapeutic agent for patients with colorectal cancer. However, its anti-cancer efficacy is restricted by drug resistance occurring through several mechanisms, including autophagy. Liensinine exerts a considerable anti-tumor effect and can regulate autophagy. Inhibition of autophagy is a strategy to reverse resistance to oxaliplatin. The aim of this study was to check if liensinine can enhance the therapeutic efficacy of oxaliplatin in colorectal cancer and if so, elucidate its mechanism.

METHODS

Two colorectal cancer cell lines, HCT116 and LoVo, and one normal intestinal epithelial cell, NCM-460 were used for in vitro experiments. Cell Counting Kit-8 (CCK-8), colony formation, and flow cytometry assays were used to evaluate the cytotoxicity of liensinine and oxaliplatin. Network pharmacology analysis and Human XL Oncology Array were used to screen targets of liensinine. Transfections and autophagy regulators were used to confirm these targets. The relationship between the target and clinical effect of oxaliplatin was analyzed. Patient-derived xenograft (PDX) models were used to validate the effects of liensinine and oxaliplatin.

RESULTS

CCK-8 and colony formation assays both showed that the combination treatment of liensinine and oxaliplatin exerted synergistic effects. Results of the network pharmacology analysis and Human XL Oncology Array suggested that liensinine can inhibit autophagy by targeting HIF-1α/eNOS. HIF-1α was identified as the key factor modulated by liensinine in autophagy and induces resistance to oxaliplatin. HIF-1α levels in tumor cells and prognosis for FOLFOX were negatively correlated in clinical data. The results from three PDX models with different HIF-1α levels showed their association with intrinsic and acquired resistance to oxaliplatin in these models, which could be reversed by liensinine.

CONCLUSIONS

Research on the relationship between HIF-1α levels and the clinical effect of oxaliplatin is lacking, and whether liensinine regulates HIF-1α is unknown. Our findings suggest that liensinine overcomes the resistance of colorectal cancer cells to oxaliplatin by suppressing HIF-1α levels to inhibit autophagy. Our findings can contribute to improving prognosis following colorectal cancer therapy.

Epigenetic regulation of autophagy by non-coding RNAs and exosomal non-coding RNAs in colorectal cancer: A narrative review

One of the major diseases affecting people globally is colorectal cancer (CRC), which is primarily caused by a lack of effective medical treatment and a limited understanding of its underlying mechanisms. Cellular autophagy functions to break down and eliminate superfluous proteins and substances, thereby facilitating the continual replacement of cellular elements and generating vital energy for cell processes. Non-coding RNAs and exosomal ncRNAs have a crucial impact on regulating gene expression and essential cellular functions such as autophagy, metastasis, and treatment resistance. The latest research has indicated that specific ncRNAs and exosomal ncRNA to influence the process of autophagy in CRC cells, which could have significant consequences for the advancement and treatment of this disease. It has been determined that a variety of ncRNAs have a vital function in regulating the genes essential for the formation and maturation of autophagosomes. Furthermore, it has been confirmed that ncRNAs have a considerable influence on the signaling pathways associated with autophagy, such as those involving AMPK, AKT, and mTOR. Additionally, numerous ncRNAs have the potential to affect specific genes involved in autophagy. This study delves into the control mechanisms of ncRNAs and exosomal ncRNAs and examines how they simultaneously influence autophagy in CRC.

CTCF and BORIS-mediated autophagy regulation via alternative splicing of BNIP3L in breast cancer

Autophagy is a pivotal regulatory and catabolic process, induced under various stressful conditions, including hypoxia. However, little is known about alternative splicing of autophagy genes in the hypoxic landscape in breast cancer. Our research unravels the hitherto unreported alternative splicing of BNIP3L, a crucial hypoxia-induced autophagic gene. We showed that BNIP3L, under hypoxic condition, forms two isoforms, a full-length isoform (BNIP3L-F) and a shorter isoform lacking exon 1 (BNIP3L-Δ1). The hypoxia-induced BNIP3L-F promotes autophagy, while under normoxia, the BNIP3L-Δ1 inhibits autophagy. We discovered a novel dimension of hypoxia-mediated epigenetic modification that regulates the alternative splicing of BNIP3L. Here, we showed differential DNA methylation of BNIP3L intron 1, causing reciprocal binding of epigenetic factor CCCTC-binding factor (CTCF) and its paralog BORIS. Additionally, we highlighted the role of CTCF and BORIS impacting autophagy in breast cancer. The differential binding of CTCF and BORIS results in alternative splicing of BNIP3L forming BNIP3L-F and BNIP3L-Δ1, respectively. The binding of CTCF on unmethylated BNIP3L intron 1 under hypoxia results in RNA Pol-II pause and inclusion of exon 1, promoting BNIP3L-F and autophagy. Interestingly, the binding of BORIS on methylated BNIP3L intron 1 under normoxia also results in RNA Pol-II pause but leads to the exclusion of exon 1 from BNIP3L mRNA. Finally, we reported the critical role of BORIS-mediated RNA Pol-II pause, which subsequently recruits SRSF6, redirecting the proximal splice-site selection, promoting BNIP3L-Δ1, and inhibiting autophagy. Our study provides novel insights into the potential avenues for breast cancer therapy by targeting autophagy regulation, specifically under hypoxic condition.

SIRT7 Inhibits Melanin Synthesis of PIG1 and PIG3V by Suppressing the Succinylation of EZR

Background

Vitiligo is an autoimmune disease characterized by loss of skin pigmentation and currently has no effective treatment. This study aimed to investigate the function of SIRT7, being an important desuccinylase mediating multiple disease progression, and its mechanism in vitiligo progression.

Methods

Normal human melanocytes (NHM) PIG1 and vitiligo human melanocytes (VHM) PIG3V were utilized in this research. The role of sirtuin 7 (SIRT7) and Ezrin (EZR) on melanin synthesis was investigated by detecting tyrosinase activity, melanin content, α-MSH levels, and the protein levels of melanin-related markers. The function of EZR was identified via rescue experiments, while the underlying mechanism was investigated via bioinformatic analysis, co-immunoprecipitation (co-IP), immunoprecipitation (IP), and Western blot techniques.

Results

Results showed that only SIRT7 was highly expressed in vitiligo human melanocytes, where knockingdown SIRT7 translated into increased melanin synthesis in melanocytes. Mechanistically, SIRT7 knockdown promoted the succinylation of EZR at the Lys (K)60 site. Moreover, overexpressing EZR induced higher melanin synthesis in melanocytes, while its knocking down exerted the opposite effect by inhibiting SIRT7 knockdown-induced melanin synthesis.

Conclusion

SIRT7 inhibited melanin synthesis in melanocytes by suppressing the succinylation of EZR. These findings are envisaged to provide a novel theoretical basis for vitiligo treatment.

Mutant TP53 promotes invasion of lung cancer cells by regulating desmoglein 3

PURPOSE

Targeted therapies have markedly improved the prognosis of lung cancer patients; nevertheless, challenges persist, including limited beneficiary populations and the emergence of drug resistance. This study investigates the molecular mechanisms of mutant TP53 in lung cancer, aiming to contribute to novel strategies for targeted therapy.

METHODS

The TCGA database was employed to delineate the mutational landscape of TP53 in lung cancer patients. Differential gene expression between TP53-mutant and wild-type patients was analyzed, followed by functional enrichment. DSG3 protein expression in lung cancer patients was assessed using IHC, and its impact on prognosis was analyzed in the TCGA database. The influence of TP53 on the downstream gene DSG3 was investigated using qPCR, ChIP-qPCR, and luciferase reporter gene assays. Protein enrichment in the DSG3 promoter region was examined through IP-MS, and the regulatory role of the HIF1-α/TP53 complex on DSG3 was explored using Co-IP, luciferase assays, and ChIP-qPCR. Molecular interactions between TP53 (R273H) and HIF1-α were detected through immunoprecipitation and molecular docking. The effects and mechanisms of DSG3 on lung cancer phenotypes were assessed through WB, transwell, and wound healing assays.

RESULTS

TP53 mutations were present in 47.44% of patients, predominantly as missense mutations. DSG3 exhibited high expression in TP53-mutant lung cancer patients, and this elevated expression correlated with a poorer prognosis. TP53 interference led to a reduction in DSG3 mRNA expression, with TP53 mutant P53 enriching at the P2 site of the DSG3 promoter region, a recruitment facilitated by HIF1-α. The DBD region of TP53 (R273H) demonstrated interaction with HIF1-α. DSG3, activated through Ezrin phosphorylation, played a role in promoting invasion and metastasis.

CONCLUSIONS

Mutant TP53 facilitates lung cancer cell invasion by modulating desmoglein 3.

Feedback loop between hypoxia and energy metabolic reprogramming aggravates the radioresistance of cancer cells

Radiotherapy is one of the mainstream approaches for cancer treatment, although the clinical outcomes are limited due to the radioresistance of tumor cells. Hypoxia and metabolic reprogramming are the hallmarks of tumor initiation and progression and are closely linked to radioresistance. Inside a tumor, the rate of angiogenesis lags behind cell proliferation, and the underdevelopment and abnormal functions of blood vessels in some loci result in oxygen deficiency in cancer cells, i.e., hypoxia. This prevents radiation from effectively eliminating the hypoxic cancer cells. Cancer cells switch to glycolysis as the main source of energy, a phenomenon known as the Warburg effect, to sustain their rapid proliferation rates. Therefore, pathways involved in metabolic reprogramming and hypoxia-induced radioresistance are promising intervention targets for cancer treatment. In this review, we discussed the mechanisms and pathways underlying radioresistance due to hypoxia and metabolic reprogramming in detail, including DNA repair, role of cancer stem cells, oxidative stress relief, autophagy regulation, angiogenesis and immune escape. In addition, we proposed the existence of a feedback loop between energy metabolic reprogramming and hypoxia, which is associated with the development and exacerbation of radioresistance in tumors. Simultaneous blockade of this feedback loop and other tumor-specific targets can be an effective approach to overcome radioresistance of cancer cells. This comprehensive overview provides new insights into the mechanisms underlying tumor radiosensitivity and progression.

Integration of machine learning for developing a prognostic signature related to programmed cell death in colorectal cancer

BACKGROUND

Colorectal cancer (CRC) presents a significant global health burden, characterized by a heterogeneous molecular landscape and various genetic and epigenetic alterations. Programmed cell death (PCD) plays a critical role in CRC, offering potential targets for therapy by regulating cell elimination processes that can suppress tumor growth or trigger cancer cell resistance. Understanding the complex interplay between PCD mechanisms and CRC pathogenesis is crucial. This study aims to construct a PCD-related prognostic signature in CRC using machine learning integration, enhancing the precision of CRC prognosis prediction.

METHOD

We retrieved expression data and clinical information from the Cancer Genome Atlas and Gene Expression Omnibus (GEO) datasets. Fifteen forms of PCD were identified, and corresponding gene sets were compiled. Machine learning algorithms, including Lasso, Ridge, Enet, StepCox, survivalSVM, CoxBoost, SuperPC, plsRcox, random survival forest (RSF), and gradient boosting machine, were integrated for model construction. The models were validated using six GEO datasets, and the programmed cell death score (PCDS) was established. Further, the model's effectiveness was compared with 109 transcriptome-based CRC prognostic models.

RESULT

Our integrated model successfully identified differentially expressed PCD-related genes and stratified CRC samples into four subtypes with distinct prognostic implications. The optimal combination of machine learning models, RSF + Ridge, showed superior performance compared with traditional methods. The PCDS effectively stratified patients into high-risk and low-risk groups, with significant survival differences. Further analysis revealed the prognostic relevance of immune cell types and pathways associated with CRC subtypes. The model also identified hub genes and drug sensitivities relevant to CRC prognosis.

CONCLUSION

The current study highlights the potential of integrating machine learning models to enhance the prediction of CRC prognosis. The developed prognostic signature, which is related to PCD, holds promise for personalized and effective therapeutic interventions in CRC.

Clinical Implications of a Six-Protein Signature in Bone Metastasis of Renal Cell Carcinoma

Bone metastases is prevalent from renal cell carcinoma (RCC) with poor quality of life and prognosis. Our previous proteomics analysis identified dysregulated proteins in the bone-tropism RCC cells. In this study, we further examined the clinical implications of these proteins using multiple clinical cohorts. We identified 6 proteins with significant upregulation in RCC tumor tissue in comparing to tumor adjacent normal tissue (p<0.05). High expression of these 6 protein-encoding genes significantly correlates with a poor survival in the TCGA-KIRC (Kidney renal clear cell carcinoma) cohort (log-rank test p=2.7e-05), and they all individually had a reverse-correlation with the gene expression of VHL and PBRM1 (p<0.001), and positive-correlation with the expression of VEGFA (p<0.001). Further gene set variation analysis (GSVA) revealed positive correlation with Th17 cells enrichment and negative CD8 T cell infiltration in the RCC tumor microenvironment. High expression of these 6 genes in pretreatment tumors favors longer overall survival (OS)(p=0.027) in anti-PDL1 treated patients (n=428). We treated one humeral metastases RCC patient with the anti-PDL1 antibody drug atezolizumab after examined the elevated expression of the 6 proteins in his nephrectomy tumor tissue, the tumor at the fracture site shrunk remarkably after four courses of treatment. These results altogether suggest a clinical implication of the 6-protein signature in RCC bone metastasis prognosis and response to immune-checkpoint inhibitor treatment.

Role of Immune Cells and Immunotherapy in Multiple Myeloma

The clinical signs of multiple myeloma, a plasma cell (PC) dyscrasia, include bone loss, renal damage, and paraproteinemia. It can be defined as the uncontrolled growth of malignant PCs within the bone marrow. The distinctive bone marrow milieu that regulates the progression of myeloma disease involves interactions between plasma and stromal cells, and myeloid and lymphoid cells. These cells affect the immune system independently or because of a complicated web of interconnections, which promotes disease development and immune evasion. Due to the importance of these factors in the onset of disease, various therapeutic strategies have been created that either target or improve the immunological processes that influence disease progression. The immune system has a role in the mechanism of action of multiple myeloma treatments. The main contributions of immune cells to the bone marrow microenvironment, as well as how they interact and how immune regulation might lead to therapeutic effects, are covered in this study.

CircFOXO3 mediates hypoxia-induced autophagy of endometrial stromal cells in endometriosis

Endometriosis is a benign gynecological disease that shares some common features of malignancy. Autophagy plays vital roles in endometriosis and influences endometrial cell metastasis, and hypoxia was identified as the initiator of this pathological process through hypoxia inducible factor 1 alpha (HIF-1α). A newly discovered circular RNA FOXO3 (circFOXO3) is critical in cell autophagy, migration, and invasion of various diseases and is reported to be related to hypoxia, although its role in endometriosis remains to be elucidated up to now. In this study, a lower circFOXO3 expression in ectopic endometrium was investigated. Furthermore, we verified that circFOXO3 could regulate autophagy by downregulating the level of p53 protein to mediate the migration and invasion of human endometrial stromal cells (T HESCs). Additionally, the effects of HIF-1α on circFOXO3 and autophagy were examined in T HESCs. Notably, overexpression of HIF-1α could induce autophagy and inhibit circFOXO3 expression, whereas overexpressing of circFOXO3 under hypoxia significantly inhibited hypoxia-induced autophagy. Mechanistically, the direct combination between HIF-1α and HIF-1α-binding site on adenosine deaminase 1 acting on RNA (ADAR1) promoter increased the level of ADAR1 protein, which bind directly with circFOXO3 pre-mRNA to block the cyclization of circFOXO3. All these results support that hypoxia-mediated ADAR1 elevation inhibited the expression of circFOXO3, and then autophagy was induced upon loss of circFOXO3 via inhibition of p53 degradation, participating in the development of endometriosis.

Multi-omics data-based analysis characterizes molecular alterations of the vesicle genes in human colorectal cancer

The role of vesicular genes in the development of colorectal cancer (CRC) is crucial. Analyzing alterations in these genes at multi-omics can aid in understanding the molecular pathways behind colorectal carcinogenesis and identifying potential treatment targets. However, studies on the overall alteration of vesicular genes in CRC are still lacking. In this study, we aimed to investigate the relationship between vesicle genetic alterations and CRC progression. To achieve this, we analyzed molecular alterations in CRC vesicle genes at eight levels, including mRNA, protein, and epigenetic levels. Additionally, we examined CRC overall survival-related genes that were obtained from a public database. Our analysis of chromatin structural variants, DNA methylation, chromatin accessibility, and proteins (including phosphorylation, ubiquitination, and malonylation), along with RNA-seq data from the TCGA database, revealed multiple levels of alterations in CRC vesicle genes in the collected tissue samples. We progressively examined the alterations of vesicle genes in mRNA and protein levels in CRC and discovered the hub genes. Further investigation identified the probable essential transcription factors. This study contributes to a thorough knowledge of the connection between vesicle gene alterations at multiple levels and the development of CRC and offers a theoretical framework for the identification of novel treatment targets.

SOX4/HDAC2 Axis Enhances Cell Survivability and Reduces Apoptosis by Activating AKT/MAPK Signaling in Colorectal Cancer

BACKGROUND

Increased SOX4 (SRY-related HMG-box) activity aids cellular transformation and metastasis. However, its specific functions and downstream targets remain to be completely elusive in colorectal cancer (CRC).

AIMS

To investigate the role of SOX4 in CRC progression and the underlying mechanism.

METHODS

In the current study, online available datasets of CRC patients were explored to check the expression status of SOX4. To investigate the further functions, SOX4 was overexpressed and knocked down in CRC cells. Colony formation assay, flowcytometry analysis, and MTT assay were used to check for proliferation and apoptosis. Acridine orange staining was done to check the role of SOX4 in autophagy induction. Furthermore, western blot, qRT-PCR, and bioinformatic analysis was done to elucidate the downstream molecular mechanism of SOX4.

RESULTS

GEPIA database showed enhanced expression of SOX4 mRNA in CRC tumor, and the human protein atlas (HPA) showed strong staining of SOX4 protein in tumor when compared to the normal tissue. Ectopic expression of SOX4 enhanced colony formation ability as well as rescued cells from apoptosis. SOX4 overexpressed cells showed the formation of acidic vesicular organelles (AVOs) which indicated autophagy. Further results revealed the activation of p-AKT/MAPK molecules upon overexpression of SOX4. SOX4 expression was found to be positively correlated with histone deacetylase 2 (HDAC2). Knockdown of SOX4 or HDAC2 inhibition induced apoptosis, revealed by decrease in BCL2 and increase in BAX expression, and inactivated the p-AKT/MAPK signaling.

CONCLUSION

The study uncovers that SOX4/HDAC2 axis improves cell survivability and reduces apoptosis via activation of the p-AKT/MAPK pathway.

Advances in the study of autophagy in breast cancer

Breast cancer is the most prevalent malignant tumor among women, with a high incidence and mortality rate all year round, which seriously affects women's health. Autophagy, a well-conserved cellular process inherent in eukaryotic organisms, plays a pivotal role in degrading damaged proteins and organelles, recycling their breakdown products to aid cells in navigating stress and gradually restoring homeostatic equilibrium. Recent studies have unveiled the intricate connection between autophagy and breast cancer. Autophagy is a double-edged sword in breast cancer, demonstrating a dual role: restraining its onset and progression on one hand, while promoting its metastasis and advancement on the other. It is also because of this interrelationship between the two that regulation of autophagy in the treatment of breast cancer is now an important strategy in clinical treatment. In this article, we systematically survey the recent research findings, elucidating the multifaceted role of autophagy in breast cancer and its underlying mechanisms, with the aim of contributing new references to the clinical management of breast cancer.

Resveratrol-laden mesoporous silica nanoparticles regulate the autophagy and apoptosis via ROS-mediated p38-MAPK/HIF-1a /p53 signaling in hypertrophic scar fibroblasts

Background

During the regression of hypertrophic scars, autophagy and apoptosis are the main ways of cell death. Recent investigations demonstrated effective inhibition of resveratrol on hypertrophic scar fibroblasts (HSFs). But its therapeutic value is limited by chemical instability and hydrophobicity, as well as the mechanism of its role in regulation of autophagy and apoptosis remains unknown.

Aim of the study

We prepared a mesoporous silica nanoparticle laden with resveratrol (MSN@Res) which can effectively improve the solubility and stability of resveratrol. The purpose of this study was to investigate whether MSN@Res regulate autophagy and apoptosis of HSFs via inhibition of ROS/p38/HIF-1α/p53 signaling axis, as to reveal its pharmacological action and target.

Materials and methods

Network pharmacology, molecular docking, and in vitro assays were carried out in this study. An in vitro model of fibroblasts cultivated in hypoxic and ischemic situations was established to simulate the scar in the proliferative phase.

Results

MSN@Res surpresses HSFs by reducing physiological autophagy and inducing apoptosis, autosis may be another cell death involed in this process. According to the network pharmacological analysis and molecular docking, the mechanism by which MSN@Res alleviates hypertrophic scar may be closely related to the MAPK signaling pathway. MSN@Res significantly downregulate the expression of HIF-1α and p53 through the inhibition of ROS induced p38-MAPK phosphorylation with corresponding changes in the expression of autophagy and apoptosis related protein.

Conclusion

MSN@Res is a novel drug delivery system with excellent chemical stability and drug release performance. It can inhibit protective autophagy of fibroblasts in hypoxic environment, and induce the apoptosis and autosis via the ROS -mediated p38-MAPK/HIF-1α/p53 signaling axis.

Autophagy-modulating biomembrane nanostructures: A robust anticancer weapon by modulating the inner and outer cancer environment

Recently, biomembrane nanostructures, such as liposomes, cell membrane-coated nanostructures, and exosomes, have demonstrated promising anticancer therapeutic effects. These nanostructures possess remarkable biocompatibility, multifunctionality, and low toxicity. However, their therapeutic efficacy is impeded by chemoresistance and radiotherapy resistance, which are closely associated with autophagy. Modulating autophagy could enhance the therapeutic sensitivity and effectiveness of these biomembrane nanostructures by influencing the immune system and the cancer microenvironment. For instance, autophagy can regulate the immunogenic cell death of cancer cells, antigen presentation of dendritic cells, and macrophage polarization, thereby activating the inflammatory response in the cancer microenvironment. Furthermore, combining autophagy-regulating drugs or genes with biomembrane nanostructures can exploit the targeting and long-term circulation properties of these nanostructures, leading to increased drug accumulation in cancer cells. This review explores the role of autophagy in carcinogenesis, cancer progression, metastasis, cancer immune responses, and resistance to treatment. Additionally, it highlights recent research advancements in the synergistic anticancer effects achieved through autophagy regulation by biomembrane nanostructures. The review also discusses the prospects and challenges associated with the future clinical translation of these innovative treatment strategies. In summary, these findings provide valuable insights into autophagy, autophagy-modulating biomembrane-based nanostructures, and the underlying molecular mechanisms, thereby facilitating the development of promising cancer therapeutics.

HIF-1α/METTL1/m7G axis is involved in CRC response to hypoxia

BACKGROUND

In recent years, many studies have confirmed that hypoxia and hypoxia inducible factor (HIF)-1α drive the development of colorectal cancer (CRC). HIF-1α also modulates epitranscriptomic remodeling to regulate cancer development. However, the mechanism by which RNA methylation is altered under hypoxic conditions and the underlying regulatory mechanisms in CRC remain unclear.

METHODS

Here, seven common types of modifications of mRNA and tRNA were quantitated using liquid chromatography-tandem mass spectrometry. To validate the robustness of the profiling data, modifications that were consistently altered across the three CRC cell lines under hypoxia were validated via dot blot analysis. Then, 10 enzymes that could regulate the abundance of three RNA modifications in tRNA were measured in CRC cells after hypoxia treatment using quantitative real-time polymerase chain reaction. Furthermore, the regulatory role of HIF-1α in the expression of methyltransferase 1 (METTL1) under hypoxic conditions was confirmed using METTL1 promoter activity assays and HIF-1α small interfering RNA (siRNA). The binding capacity of HIF-1α to each hypoxia response element (HRE) in the promoter of METTL1 was investigated by performing Chromatin immunoprecipitation assay (ChIP).

RESULTS

Abundance of RNA modifications was altered more consistently and significantly in tRNA than in mRNA under hypoxic conditions. In addition, the abundance of N7-methyleguanosine (m7G) modification in tRNA decreased significantly under hypoxic conditions. As a methyltransferase of the m7G modification in tRNA, the expression of METTL1 mRNA was drastically downregulated under hypoxic conditions. Mechanistically, suppression of HIF-1α by siRNA upregulated the METTL1 promoter activity. Furthermore, ChIP showed that HIF-1α could bind with an HRE in the promoter region of METTL1, indicating that METTL1 is a direct target of HIF-1α in CRC cells under hypoxic conditions.

CONCLUSIONS

Our study revealed that the abundance of the m7G modification in tRNA was drastically reduced in CRC cells dependent on the HIF-1α-mediated inhibition of METTL1 transcription under hypoxic conditions.

The dual role of MiR-210 in the aetiology of cancer: A focus on hypoxia-inducible factor signalling

Tumorigenesis exemplifies the complex process of neoplasm origination, which is characterised by somatic genetic alterations and abnormal cellular growth. This multidimensional phenomenon transforms previously dormant cells into malignant equivalents, resulting in uncontrollable proliferation and clonal expansion. Various elements, including random mutations, harmful environmental substances, and genetic predispositions, influence tumorigenesis's aetiology. MicroRNAs (miRNAs) are now recognised as crucial determinants of gene expression and key players in several biological methods, including oncogenesis. A well-known hypoxia-inducible miRNA is MiR-210, which is of particular interest because of its complicated role in the aetiology of cancer and a variation of physiological and pathological situations. MiR-210 significantly impacts cancer by controlling the hypoxia-inducible factor (HIF) signalling pathway. By supporting angiogenesis, metabolic reprogramming, and cellular survival in hypoxic microenvironments, HIF signalling orchestrates adaptive responses, accelerating the unstoppable development of tumorous growth. Targeting several components of this cascade, including HIF-1, HIF-3, and FIH-1, MiR-210 plays a vital role in modifying HIF signalling and carefully controlling the HIF-mediated response and cellular fates in hypoxic environments. To understand the complexities of this relationship, careful investigation is required at the intersection of MiR-210 and HIF signalling. Understanding this relationship is crucial for uncovering the mechanisms underlying cancer aetiology and developing cutting-edge therapeutic approaches. The current review emphasises MiR-210's significance as a vital regulator of the HIF signalling cascade, with substantial implications spanning a range of tumor pathogenesis.

Genetic variants in hypoxia-inducible factor pathway are associated with colorectal cancer risk and immune infiltration

Hypoxia-inducible factor (HIF) pathway genes influence tumorigenesis and immune status. However, the associations between genetic variants in hypoxia-related genes and colorectal cancer risk and the immune status of hypoxia-associated genes in colorectal cancer have not been systematically characterized. The associations between genetic variants and colorectal cancer risk were evaluated in Chinese, Japanese and European populations using logistic regression analysis. The relationships between target genes and tumour immune infiltration were predicted by Tumour Immune Estimation Resource (TIMER). We found that rs34533650 in EPAS1 was associated with colorectal cancer risk (OR = 1.43, 95% CI = 1.20-1.70, P(FDR)  = 8.35 × 10-4 ), and this finding was validated in two independent populations (Japanese: OR = 1.07, 95% CI = 1.01-1.15, p = 3.38 × 10-2 ; European: OR = 1.11, 95% CI = 1.03-1.19, p = 6.04 × 10-3 ). EPAS1-associated genes were enriched in immune-related pathways. In addition, we found that EPAS1 copy number variation (CNV) was associated with the degree of infiltration of immune cells and observed correlations between EPAS1 expression and immune cell infiltration levels in colorectal cancer. These results highlight that genetic variants of hypoxia-related genes play roles in colorectal cancer risk and provide new insight that EPAS1 might be a promising predictor of colorectal cancer susceptibility and immune status.

Colorectal Cancer in Correlation With Clinicopathological Variables: The Effects of Hypoxia-Inducible Factor-1 Alfa or the InterLeukin-33 and Vascular Endothelial Growth Factor?

Background The hypoxia-inducible factor-1 alpha (HIF-1α) is believed to control angiogenesis and metabolism by upregulating hypoxia-induced genes, such as the interLeukin-33 (IL-33) gene and vascular endothelial growth factor (VEGF) gene. The study aimed to study the HIF-1α and its two hypoxia pathway genes; IL-33 and VEGF, together with the angiogenesis and correlate them with some prognostic clinicopathological features, separately and in combination to assess their dependency. Methodology This study included 87 colorectal cancer (CRC) cases, diagnosed between January 2019 and December 2022. Different prognostic clinicopathological features were examined and tissue microarray (TMA) slides were designed to carry out IHC for IL-33 and VEGF scoring in tumor cells, in addition to qualitative interpretation of VEGF expression in tumor vessels. Molecular analysis was performed for HIF-1α and all data were correlated to the clinicopathological features, separately and collectively, to assess the dependency of these factors. Results No statistical correlation could be seen among the IL-33, VEGF, and prognostic clinicopathological features. Whereas analysis of the HIF-1α alone showed significantly high mean expression in patients with distance metastasis and was increased with the increased involvement of the lymph nodes (LNs). However, when the HIF 1-α expression was correlated with the clinicopathological characteristics on the bases of VEGF and IL-33 expressions the significant association with metastasis disappeared in tumor cells and appeared only with the endothelium of the tumor angiogenesis. Moreover, the results conflicted with the LNs involvement. Conclusions These findings may suggest a role of HIF 1-α in the downstream regulation of biomarkers other than the VEGF and IL-33, which needs to uncover pathways and novel factors regulated by the HIF 1-α for the proinflammation and angiogenesis in malignancy.

Proteomic characterization of the colorectal cancer response to chemoradiation and targeted therapies reveals potential therapeutic strategies

Chemoradiation and targeted therapies are the major treatments for colorectal cancer (CRC); however, molecular properties associated with therapy resistance are incompletely characterized. Here, we profile the proteome of 254 tumor tissues from patients with CRC undergoing chemotherapy, chemoradiation, or chemotherapy combined with targeted therapy. Proteome-based classification reveals four subtypes featured with distinct biological and therapeutic characteristics. The integrative analysis of CRC cell lines and clinical samples indicates that immune regulation is significantly associated with drug sensitivity. HSF1 can increase DNA damage repair and cell cycle, thus inducing resistance to radiation, while high expression of HDAC6 is negatively associated with response of cetuximab. Furthermore, we develop prognostic models with high accuracy to predict the therapeutic response, further validated by parallel reaction monitoring (PRM) assay in an independent validation cohort. This study provides a rich resource for investigating the mechanisms and indicators of chemoradiation and targeted therapy in CRC.

Characterization of 3D NSCLC Cell Cultures with Fibroblasts or Macrophages for Tumor Microenvironment Studies and Chemotherapy Screening

The study of 3D cell culture has increased in recent years as a model that mimics the tumor microenvironment (TME), which is characterized by exhibiting cellular heterogeneity, allowing the modulation of different signaling pathways that enrich this microenvironment. The TME exhibits two main cell populations: cancer-associated fibroblasts (CAFs) and tumor-associated macrophages (TAM). The aim of this study was to investigate 3D cell cultures of non-small cell lung cancer (NSCLC) alone and in combination with short-term cultured dermal fibroblasts (FDH) and with differentiated macrophages of the THP-1 cell line. Homotypic and heterotypic spheroids were morphologically characterized using light microscopy, immunofluorescence and transmission electron microscopy. Cell viability, cycle profiling and migration assay were performed, followed by the evaluation of the effects of some chemotherapeutic and potential compounds on homotypic and heterotypic spheroids. Both homotypic and heterotypic spheroids of NSCLC were generated with fibroblasts or macrophages. Heterotypic spheroids with fibroblast formed faster, while homotypic ones reached larger sizes. Different cell populations were identified based on spheroid zoning, and drug effects varied between spheroid types. Interestingly, heterotypic spheroids with fibroblasts showed similar responses to the treatment with different compounds, despite being smaller. Cellular viability analysis required multiple methods, since the responses varied depending on the spheroid type. Because of this, the complexity of the spheroid should be considered when analyzing compound effects. Overall, this study contributes to our understanding of the behavior and response of NSCLC cells in 3D microenvironments, providing valuable insights for future research and therapeutic development.

The Mechanism of Ubiquitination or Deubiquitination Modifications in Regulating Solid Tumor Radiosensitivity

Radiotherapy, a treatment method employing radiation to eradicate tumor cells and subsequently reduce or eliminate tumor masses, is widely applied in the management of numerous patients with tumors. However, its therapeutic effectiveness is somewhat constrained by various drug-resistant factors. Recent studies have highlighted the ubiquitination/deubiquitination system, a reversible molecular modification pathway, for its dual role in influencing tumor behaviors. It can either promote or inhibit tumor progression, impacting tumor proliferation, migration, invasion, and associated therapeutic resistance. Consequently, delving into the potential mechanisms through which ubiquitination and deubiquitination systems modulate the response to radiotherapy in malignant tumors holds paramount significance in augmenting its efficacy. In this paper, we comprehensively examine the strides made in research and the pertinent mechanisms of ubiquitination and deubiquitination systems in governing radiotherapy resistance in tumors. This underscores the potential for developing diverse radiosensitizers targeting distinct mechanisms, with the aim of enhancing the effectiveness of radiotherapy.

Hypoxia-induced the upregulation of NDUFA4L2 promoted colon adenocarcinoma progression through ROS-mediated PI3K/AKT pathway

The NADH dehydrogenase (ubiquinone) 1 alpha subcomplex 4-like 2 (NDUFA4L2) gene has been reported to be upregulated in colorectal cancer (CRC) and is associated with worse prognosis. However, the specific function and underlying mechanism of NDUFA4L2 in colon adenocarcinoma (COAD) under hypoxia has never been investigated. Our study discovered that hypoxia promoted the viability, metastasis, and epithelial-mesenchymal transition (EMT) of COAD cells. Besides, hypoxia-induced HIF-1α upregulated the expression of NDUFA4L2 which served as an oncogene and an independent diagnostic and prognostic marker in COAD. Under hypoxic environment, NDUFA4L2 mediated the viability, metastasis, and epithelial-EMT of COAD cells. Additionally, the ROS-dependent PI3K/Akt signaling was activated by NDUFA4L2 in COAD in hypoxia and NDUFA4L2 facilitated the malignant behaviors of hypoxia-treated COAD cells by elevating ROS production. Collectively, abundant NDUFA4L2 expression induced by HIF-1α under hypoxia promoted the development of COAD through activation of the PI3K/AKT signaling in a ROS-dependent manner, indicating NDUFA4L2 as a promising target in COAD diagnosis and treatment.

A Nano-Autophagy Inhibitor Triggering Reciprocal Feedback Control of Cholesterol Depletion for Solid Tumor Therapy

Solid tumors are characterized by enhanced metabolism of lipid, particularly cholesterol, inspiring the exploration of metabolic therapy through cholesterol oxidase (COD)-mediated cholesterol deprivation. However, the therapeutic efficacy of COD is limited due to the hypoxic tumor microenvironment and the protective autophagy triggered by cholesterol deprivation. Herein, a combination therapy for metabolically treating solid tumors through COD in conjunction with molybdenum oxide nanodots (MONDs), which serve as both potent oxygen generators and autophagy inhibitors, is reported. MONDs convert H2 O2 (arising from COD-mediated cholesterol oxidation) into O2 , which is then recycled by COD to form reciprocal feedback for cholesterol depletion. Concurrently, MONDs can overcome autophagy-induced therapeutic resistance frequently occurring in conventional nutrient deprivation therapy by activating AKT/mTOR pathway phosphorylation. Combination therapy in the xenograft model results in an ≈5-fold increase in therapeutic efficiency as compared with COD treatment alone. This functionally cooperative metabolic coupling strategy holds great promise as a novel polytherapy approach that will benefit patients with solid tumors.

Long Noncoding RNA URB1-Antisense RNA 1 (AS1) Suppresses Sorafenib-Induced Ferroptosis in Hepatocellular Carcinoma by Driving Ferritin Phase Separation

Sorafenib, a first-line molecular-target drug for advanced hepatocellular carcinoma (HCC), has been shown to be a potent ferroptosis inducer in HCC. However, we found that there was a lower level of ferroptosis in sorafenib-resistant HCC samples than in sorafenib-sensitive HCC samples, suggesting that sorafenib resistance in HCC may be a result of ferroptosis suppression. Recent reports have shown that long noncoding RNAs (lncRNAs) are involved in programmed cell death (PCD), including apoptosis and ferroptosis. This study aimed to investigate the roles and underlying molecular mechanisms of lncRNAs in sorafenib-induced ferroptosis in HCC cells. Using lncRNA sequencing, we identified a ferroptosis-related lncRNA, URB1-antisense RNA 1 (AS1), which was highly expressed in sorafenib-resistant HCC samples and predicted poor survival in HCC. Furthermore, URB1-AS1 mitigates sorafenib-induced ferroptosis by inducing ferritin phase separation and reducing the cellular free iron content. Hypoxia inducible factor (HIF)-1α was identified as a key factor promoting URB1-AS1 expression in sorafenib-resistant HCC cells. Notably, we found that specifically inhibiting the expression of URB1-AS1 with N-acetylgalactosamine (GalNAc)-small interfering (si)URB1-AS1 successfully enhanced the sensitivity of HCC cells to sorafenib in an in vivo tumor model. Our study uncovered a critical role for URB1-AS1 in the repression of ferroptosis, suggesting URB1-AS1 targeting may represent a potential approach to overcome sorafenib resistance in HCC.

Advancement in precision diagnosis and therapeutic for triple-negative breast cancer: Harnessing diagnostic potential of CRISPR-cas & engineered CAR T-cells mediated therapeutics

Cancer is characterized by uncontrolled cell growth, disrupted regulatory pathways, and the accumulation of genetic mutations. These mutations across different types of cancer lead to disruptions in signaling pathways and alterations in protein expression related to cellular growth and proliferation. This review highlights the AKT signaling cascade and the retinoblastoma protein (pRb) regulating cascade as promising for novel nanotheranostic interventions. Through synergizing state-of-the-art gene editing tools like the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas system with nanomaterials and targeting AKT, there is potential to enhance cancer diagnostics significantly. Furthermore, the integration of modified CAR-T cells into multifunctional nanodelivery systems offers a promising approach for targeted cancer inhibition, including the eradication of cancer stem cells (CSCs). Within the context of highly aggressive and metastatic Triple-negative Breast Cancer (TNBC), this review specifically focuses on devising innovative nanotheranostics. For both pre-clinical and post-clinical TNBC detection, the utilization of the CRISPR-Cas system, guided by RNA (gRNA) and coupled with a fluorescent reporter specifically designed to detect TNBC's mutated sequence, could be promising. Additionally, a cutting-edge approach involving the engineering of TNBC-specific iCAR and syn-Notch CAR T-cells, combined with the co-delivery of a hybrid polymeric nano-liposome encapsulating a conditionally replicative adenoviral vector (CRAdV) against CSCs, could present an intriguing intervention strategy. This review thus paves the way for exciting advancements in the field of nanotheranostics for the treatment of TNBC and beyond.

Knockdown LIMP2 inhibits colorectal cancer cells migration, invasion, and metastasis

Colorectal cancer (CRC) is a common malignancy worldwide nowadays and liver metastasis is the primary cause of death in patients with CRC. Although lysosomal integral membrane protein 2 (LIMP2) has been reported to play important roles in gastric cancer and prostate cancer, its role in CRC remains unclear. The aim of this study was to investigate the function of LIMP2 in CRC invasion and migration, along with the potential underlying molecular mechanisms. We found that LIMP2 levels were higher in CRC tissues compared to adjacent normal tissues. Kaplan-Meier survival analysis showed that high expression of LIMP2 was associated with worse prognosis in CRC patients. Knockdown of LIMP2 significantly inhibited invasion, migration, and wound healing abilities of CRC cells in vitro, and inhibited CRC liver metastasis in vivo. Additionally, LIMP2 knockdown inhibited autophagy in CRC. Therefore, LIMP2 plays an important role in CRC progression. High expression of LIMP2 was associated with worse prognosis in CRC patients. Knockdown LIMP2 can effectively inhibit CRC cell migration and invasion in vitro and prevent liver metastasis in vivo. These findings suggest that LIMP2 may serve as an independent prognostic factor and potential therapeutic target for CRC.

Targeting redox regulation and autophagy systems in cancer stem cells

Cancer is a dysregulated cellular level pathological condition that results in tumor formation followed by metastasis. In the heterogeneous tumor architecture, cancer stem cells (CSCs) are essential to push forward the progression of tumors due to their strong pro-tumor properties such as stemness, self-renewal, plasticity, metastasis, and being poorly responsive to radiotherapy and chemotherapeutic agents. Cancer stem cells have the ability to withstand various stress pressures by modulating transcriptional and translational mechanisms, and adaptable metabolic changes. Owing to CSCs heterogeneity and plasticity, these cells display varied metabolic and redox profiles across different types of cancers. It has been established that there is a disparity in the levels of Reactive Oxygen Species (ROS) generated in CSCs vs Non-CSC and these differential levels are detected across different tumors. CSCs have unique metabolic demands and are known to change plasticity during metastasis by passing through the interchangeable epithelial and mesenchymal-like phenotypes. During the metastatic process, tumor cells undergo epithelial to mesenchymal transition (EMT) thus attaining invasive properties while leaving the primary tumor site, similarly during the course of circulation and extravasation at a distant organ, these cells regain their epithelial characteristics through Mesenchymal to Epithelial Transition (MET) to initiate micrometastasis. It has been evidenced that levels of Reactive Oxygen Species (ROS) and associated metabolic activities vary between the epithelial and mesenchymal states of CSCs. Similarly, the levels of oxidative and metabolic states were observed to get altered in CSCs post-drug treatments. As oxidative and metabolic changes guide the onset of autophagy in cells, its role in self-renewal, quiescence, proliferation and response to drug treatment is well established. This review will highlight the molecular mechanisms useful for expanding therapeutic strategies based on modulating redox regulation and autophagy activation to targets. Specifically, we will account for the mounting data that focus on the role of ROS generated by different metabolic pathways and autophagy regulation in eradicating stem-like cells hereafter referred to as cancer stem cells (CSCs).

ROS impairs tumor vasculature normalization through an endocytosis effect of caveolae on extracellular SPARC

BACKGROUND

The accumulation of reactive oxygen species (ROS) in tumor microenvironment (TME) is an important player for tumorigenesis and progression. We aimed to explore the outcomes of ROS on tumor vessels and the potential regulated mechanisms.

METHODS

Exogenous H₂O₂ was adopted to simulate the ROS setting. Immunofluorescence staining and ultrasonography were used to assess the vascular endothelial coverage and perfusions in the tumors inoculated with Lewis lung cancer (LLC) and melanoma (B16F10) cells of C57BL/6 mice, respectively. ELISA and western-blot were used to detect the expression of secreted acidic and cysteine-rich protein (SPARC) and Caveale-1 in human umbilical vein endothelial cells (HUVEC) extra- and intracellularly. Intracellular translocation of SPARC was observed using electron microscopy and immunofluorescence approaches.

RESULT

Under the context of oxidative stress, the pericyte recruitment of neovascularization in mouse lung cancer and melanoma tissues would be aberrated, which subsequently led to the disruption of the tumor vascular architecture and perfusion dysfunction. In vitro, HUVEC extracellularly SPARC was down-regulated, whereas intracellularly it was up-regulated. By electron microscopy and immunofluorescence staining, we observed that SPARC might undergo transmembrane transport via caveale-1-mediated endocytosis. Finally, the binding of SPARC to phosphorylated-caveale-1 was also detected in B16F10 tissues.

CONCLUSION

In the oxidative stress environment, neovascularization within the tumor occurs structural deterioration and decreased perfusion capacity. One of the main regulatory mechanisms is the migration of extracellular SPARC from the endothelium to intracellular compartments via Caveolin-1 carriers.

Highlighting functions of apoptosis and circular RNAs in colorectal cancer

Colorectal cancer (CRC) is known as one of the global problems that endangers the lives of thousands of people every year. Various treatments have been used to deal with this disease, but in some cases, they are not effective. Circular RNAs, as a novel class of noncoding RNAs, have different expression levels and various functions in cancer cells, such as gene regulation through microRNA sponging. They play an important role in various cellular processes, including differentiation, proliferation, invasion, and apoptosis. Changes in the process of apoptosis are closely related to the progression or inhibition of various malignancies. Induction of apoptosis in cancer cells is a promising target for tumor therapy. In this study, circRNAs were investigated as being central to the induction or inhibition of apoptosis in CRC. It is hoped that through targeted changes in the function of these biomolecules, better outcomes will be achieved in cancer treatment. Perhaps better outcomes for cancer treatment can be achieved by using new methods and modifying the expression of these nucleic acids. However, using this method may come with challenges and limitations.

Nickel nanoparticles induce autophagy and apoptosis via HIF-1α/mTOR signaling in human bronchial epithelial cells

With the rapid development of nanotechnology, the potential adverse health effects of nanoparticles have been caught more attention and become global concerns. However, the underlying mechanisms in metal nanoparticle-induced toxic effects are still largely obscure. In this study, we investigated whether exposure to nickel nanoparticles (Nano-Ni) and titanium dioxide nanoparticles (Nano-TiO2) would alter autophagy and apoptosis levels in normal human bronchial epithelial BEAS-2B cells and the underlying mechanisms involved in this process. Our results showed that the expressions of autophagy- and apoptosis-associated proteins were dysregulated in cells exposed to Nano-Ni. However, exposure to the same doses of Nano-TiO2 had no significant effects on these proteins. In addition, exposure to Nano-Ni, but not Nano-TiO2, led to nuclear accumulation of HIF-1α and decreased phosphorylation of mTOR in BEAS-2B cells. Inhibition of HIF-1α by CAY10585 abolished Nano-Ni-induced decreased phosphorylation of mTOR, while activation of mTOR by MHY1485 did not affect Nano-Ni-induced nuclear accumulation of HIF-1α. Furthermore, both HIF-1α inhibition and mTOR activation abolished Nano-Ni-induced autophagy but enhanced Nano-Ni-induced apoptosis. Blockage of autophagic flux by Bafilomycin A1 exacerbated Nano-Ni-induced apoptosis, while activation of autophagy by Rapamycin effectively rescued Nano-Ni-induced apoptosis. In conclusion, our results demonstrated that Nano-Ni exposure caused increased levels of autophagy and apoptosis via the HIF-1α/mTOR signaling axis. Nano-Ni-induced autophagy has a protective role against Nano-Ni-induced apoptosis. These findings provide us with further insight into Nano-Ni-induced toxicity.

Unraveling Colorectal Cancer and Pan-cancer Immune Heterogeneity and Synthetic Therapy Response Using Cuproptosis and Hypoxia Regulators by Multi-omic Analysis and Experimental Validation

Cuproptosis, a new type of programmed cell death (PCD), is closely related to cellular tricarboxylic acid cycle and cellular respiration, while hypoxia can modulate PCD. However, their combined contribution to tumor subtyping remains unexplored. Here, we applied a multi-omics approach to classify TCGA_COADREAD based on cuproptosis and hypoxia. The classification was validated in three colorectal cancer (CRC) cohorts and extended to a pan-cancer analysis. The results demonstrated that pan-cancers, including CRC, could be divided into three distinct subgroups (cuproptosis-hypoxia subtypes, CHSs): CHS1 had active metabolism and poor immune infiltration but low fibrosis; CHS3 had contrasting characteristics with CHS1; CHS2 was intermediate. CHS1 may respond well to cuproptosis inducers, and CHS3 may benefit from a combination of immunotherapy and anti-fibrosis/anti-hypoxia therapies. In CRC, the CHSs also showed a significant difference in prognosis and sensitivity to classic drugs. Organoid-based drug sensitivity assays validated the results of transcriptomics. Cell-based assays indicated that masitinib and simvastatin had specific effects on CHS1 and CHS3, respectively. A user-friendly website based on the classifier was developed (https://fan-app.shinyapps.io/chs_classifier/) for accessibility. Overall, the classifier based on cuproptosis and hypoxia was applicable to most pan-cancers and could aid in personalized cancer therapy.

Different Roles of Apoptosis and Autophagy in the Development of Human Colorectal Cancer

Colorectal cancer (CRC) remains a major life-threatening malignancy, despite numerous therapeutic and screening attempts. Apoptosis and autophagy are two processes that share common signaling pathways, are linked by functional relationships and have similar protein components. During the development of cancer, the two processes can trigger simultaneously in the same cell, causing, in some cases, an inhibition of autophagy by apoptosis or apoptosis by autophagy. Malignant cells that have accumulated genetic alterations can take advantage of any alterations in the apoptotic process and as a result, progress easily in the cancerous transformation. Autophagy often plays a suppressive role during the initial stages of carcinogenicity, while in the later stages of cancer development it can play a promoting role. It is extremely important to determine the regulation of this duality of autophagy in the development of CRC and to identify the molecules involved, as well as the signals and the mechanisms behind it. All the reported experimental results indicate that, while the antagonistic effects of autophagy and apoptosis occur in an adverse environment characterized by deprivation of oxygen and nutrients, leading to the formation and development of CRC, the effects of promotion and collaboration usually involve an auxiliary role of autophagy compared to apoptosis. In this review, we elucidate the different roles of autophagy and apoptosis in human CRC development.