Cell migration and proliferation are regulated by miR-26a in colorectal cancer via the PTEN-AKT axis

Helminth-derived molecules improve 5-fluorouracil treatment on experimental colon tumorigenesis

Colorectal cancer (CRC) is one of the most prevalent fatal neoplasias worldwide. Despite efforts to improve the early diagnosis of CRC, the mortality rate of patients is still nearly 50%. The primary treatment strategy for CRC is surgery, which may be accompanied by chemotherapy and radiotherapy. The conventional and first-line chemotherapeutic agent utilized is 5-fluorouracil (5FU). However, it has low efficiency. Combination treatment with leucovorin and oxaliplatin or irinotecan improves the effectiveness of 5FU therapy. Unfortunately, most patients develop drug resistance, leading to disease progression. Here, we evaluated the effect of a potential alternative adjuvant treatment for 5FU, helminth-derived Taenia crassiceps (TcES) molecules, on treating advanced colitis-associated colon cancer. The use of TcES enhanced the effects of 5FU on established colonic tumors by downregulating the expression of the immunoregulatory cytokines, Il-10 and Tgf-β, and proinflammatory cytokines, Tnf-α and Il-17a, and reducing the levels of molecular markers associated with malignancy, cyclin D1, and Ki67, both involved in apoptosis inhibition and the signaling pathway of β-catenin. TcES+5FU therapy promoted NK cell recruitment and the release of Granzyme B1 at the tumor site, consequently inducing tumor cell death. Additionally, it restored P53 activity which relates to decreased Mdm2 expression. In vitro assays with human colon cancer cell lines showed that therapy with TcES+5FU significantly reduced cell proliferation and migration by modulating the P53 and P21 signaling pathways. Our findings demonstrate, for the first time in vivo, that helminth-derived excreted/secreted products may potentiate the effect of 5FU on established colon tumors.

How MicroRNAs Command the Battle against Cancer

MicroRNAs (miRNAs) are small RNA molecules that regulate more than 30% of genes in humans. Recent studies have revealed that miRNAs play a crucial role in tumorigenesis. Large sets of miRNAs in human tumors are under-expressed compared to normal tissues. Furthermore, experiments have shown that interference with miRNA processing enhances tumorigenesis. Multiple studies have documented the causal role of miRNAs in cancer, and miRNA-based anticancer therapies are currently being developed. This review primarily focuses on two key points: (1) miRNAs and their role in human cancer and (2) the regulation of tumor suppressors by miRNAs. The review discusses (a) the regulation of the tumor suppressor p53 by miRNA, (b) the critical role of the miR-144/451 cluster in regulating the Itch-p63-Ago2 pathway, and (c) the regulation of PTEN by miRNAs. Future research and the perspectives of miRNA in cancer are also discussed. Understanding these pathways will open avenues for therapeutic interventions targeting miRNA regulation.

Cancer-associated fibroblasts drive colorectal cancer cell progression through exosomal miR-20a-5p-mediated targeting of PTEN and stimulating interleukin-6 production

BACKGROUND

This study evaluated the clinical relevance of a set of five serum-derived circulating microRNAs (miRNAs) in colorectal cancer (CRC). Additionally, we investigated the role of miR-20a-5p released by exosomes derived from cancer-associated fibroblasts (CAFs) in the context of CRC.

METHODS

The expression levels of five circulating serum-derived miRNAs (miR-20a-5p, miR-122-5p, miR-139-3p, miR-143-5p, and miR-193a-5p) were quantified by real-time quantitative PCR (RT-qPCR), and their associations with clinicopathological characteristics in CRC patients were assessed. The diagnostic accuracy of these miRNAs was determined through Receiver Operating Characteristic (ROC) curve analysis. CAFs and normal fibroblasts (NFs) were isolated from tissue samples, and subsequently, exosomes derived from these cells were isolated and meticulously characterized using electron microscopy and Western blotting. The cellular internalization of fluorescent-labeled exosomes was visualized by confocal microscopy. Gain- and loss-of-function experiments were conducted to elucidate the oncogenic role of miR-20a-5p transferred by exosomes derived from CAFs in CRC progression. The underlying mechanisms were uncovered through luciferase reporter assay, Western blotting, enzyme-linked immunosorbent assays, as well as proliferation and migration assays.

RESULTS

The expression levels of serum-derived circulating miR-20a-5p and miR-122-5p were significantly higher in CRC and were positively correlated with advanced stages of tumorigenesis and lymph node metastasis (LNM). In contrast, circulating miR-139-3p, miR-143-5p, and miR-193a-5p were down-regulated in CRC and associated with early tumorigenesis. Except for miR-139-3p, they showed a negative correlation with LNM status. Among the candidate miRNAs, significantly elevated levels of miR-20a-5p were observed in both cellular and exosomal fractions of CAFs. Our findings indicated that miR-20a-5p induces the expression of EMT markers, partly by targeting PTEN. Exosomal miR-20a secreted by CAFs emerged as a key factor enhancing the proliferation and migration of CRC cells. The inhibition of miR-20a impaired the proliferative and migratory potential of CAF-derived exosomes in SW480 CRC cells, suggesting that the oncogenic effects of CAF-derived exosomes are mediated through the exosomal transfer of miR-20a. Furthermore, exosomes originating from CAFs induced increased nuclear translocation of the NF-kB p65 transcription factor in SW480 CRC cells, leading to increased interleukin-6 (IL-6) production.

CONCLUSIONS

We established a set of five circulating miRNAs as a non-invasive biomarker for CRC diagnosis. Additionally, our findings shed light on the intricate mechanisms underpinning the oncogenic impacts of CAF-derived exosomes and underscore the pivotal role of miR-20a-5p in CRC progression.

Identification of expression profiles and prognostic value of RFCs in colorectal cancer

Colorectal cancer (CRC) ranks among the most prevalent cancers globally, with its incidence closely tied to DNA damage. The Replication Factor C (RFC) complexes comprises five protein subunits: RFC1, RFC2, RFC3, RFC4, and RFC5. These RFC complexes play crucial roles in DNA replication, repair pathways, activities post DNA damage, and ATP-dependent processes during DNA synthesis. However, the impact of RFC complexes proteins on CRC prognosis remains unclear. To explore this, we employed a computational analysis approach, utilizing platforms such as the DepMap portal, GEPIA, DAVID Bioinformatics for KEGG pathway analysis, Human Protein Atlas (HPA), STRING, and TIMER. Our results indicate that the mRNA levels of RFC1 and RFC5 were the least expressed among CRC cell lines compared to other RFC complex subunits. Notably, low RFC1 and RFC5 expression was correlated with poor prognosis in terms of CRC patients' overall survival (OS). Immunohistochemical results from the Human Protein Atlas demonstrated medium staining for RFC1, RFC2, and RFC5 in CRC tissues. Furthermore, the low expression of RFC1 and RFC5 showed a significant correlation with high expression levels of miR-26a-5p and miR-636, impacting cell proliferation through mismatch repair, DNA replication, and the nucleotide excision repair pathway. Although the precise functions of RFC1 in cancer are still unknown, our findings suggest that the small-molecule single target, CHEMBL430483, and multiple target molecules could be potential treatments for CRC. In conclusion, the elevated expression of miR-26a-5p and miR-636 targeting RFC1 and RFC5 expression holds promise as a potential biomarker for early-stage CRC detection. These insights provide novel directions and strategies for CRC therapies.

Correlation of PTEN signaling pathway and miRNA in breast cancer

Breast cancer (BC) is one of the most common cancers among women and can be fatal if not diagnosed and treated on time. Various genetic and environmental factors play a significant role in the development and progression of BC. Within the body, different signaling pathways have been identified that contribute to cancer progression, or conversely, cancer prevention. Phosphatase and tensin homolog (PTEN) is one of the proteins that prevent cancer by inhibiting the oncogenic PI3K/Akt/mTOR signaling pathway. MicroRNAs (miRNAs) are molecules with about 18 to 28 base pairs, which regulate about 30% of human genes after transcription. miRNAs play a key role in the progression or prevention of cancer through different signaling pathway and mechanisms, e.g., apoptosis, angiogenesis, and proliferation. miRNAs, which are upstream mediators of PTEN, can reinforce or suppress the effect of PTEN signaling on BC cells, and suppressing the PTEN signaling, linked to weakness of the cancer cells to chemotherapeutic drugs. However, the precise mechanism and function of miRNAs on PTEN in BC are not yet fully understood. Therefore, in the present study, has been focused on miRNAs regulating PTEN function in BC.

Aberrant PI3Kδ splice isoform as a potential biomarker and novel therapeutic target for endocrine cancers

Introduction

PI3K/AKT signaling pathway is upregulated in a broad spectrum of cancers. Among the class I PI3Ks (PI3Kδ/β/δ isoforms), PI3Kδ has been implicated in hematologic cancers and solid tumors. Alternative splicing is a post-transcriptional process for acquiring proteomic diversity in eukaryotic cells. Emerging evidence has highlighted the involvement of aberrant mRNA splicing in cancer development/progression.

Methods

Our previous studies revealed that PIK3CD-S is an oncogenic splice variant that promotes tumor aggressiveness and drug resistance in prostate cancer (PCa). To further evaluate the potential of utilizing PI3Kδ-S (encoded from PIK3CD-S) as a cancer biomarker and/or drug target, comprehensive analyses were performed in a series of patient samples and cell lines derived from endocrine/solid tumors. Specifically, IHC, immunofluorescence, western blot and RT-PCR assay results have demonstrated that PI3Kδ isoforms were highly expressed in endocrine/solid tumor patient specimens and cell lines.

Results

Differential PIK3CD-S/PIK3CD-L expression profiles were identified in a panel of endocrine/solid tumor cells. SiRNA knockdown of PIK3CD-L or PIK3CD-S differentially inhibits AKT/mTOR signaling in PCa, breast, colon and lung cancer cell lines. Moreover, siRNA knockdown of PTEN increased PI3Kδ levels and activated AKT/mTOR signaling, while overexpression of PTEN reduced PI3Kδ levels and inhibited AKT/mTOR signaling in cancer cells. Intriguingly, PI3Kδ-S levels remained unchanged upon either siRNA knockdown or overexpression of PTEN. Taken together, these results suggested that PTEN negatively regulates PI3Kδ-L and its downstream AKT/mTOR signaling, while PI3Kδ-S promotes AKT/mTOR signaling without regulation by PTEN. Lastly, PI3Kδ inhibitor Idelalisib and SRPK1/2 inhibitor SRPIN340 were employed to assess their efficacies on inhibiting the PI3Kδ-expressing endocrine/solid tumors. Our results have shown that Idelalisib effectively inhibited PI3Kδ-L (but not PI3Kδ-S) mediated AKT/mTOR signaling. In contrast, SRPIN340 reversed the aberrant mRNA splicing, thereby inhibiting AKT/mTOR signaling. In-vitro functional assays have further demonstrated that a combination of Idelalisib and SRPIN340 achieved a synergistic drug effect (with drastically reduced cell viabilities/growths of tumor spheroids) in inhibiting the advanced tumor cells.

Conclusion

In summary, our study has suggested a promising potential of utilizing PI3Kδ-S (an oncogenic isoform conferring drug resistance and exempt from PTEN regulation) as a prognostic biomarker and drug target in advanced endocrine cancers.

CD34+ HSPCs-derived exosomes contain dynamic cargo and promote their migration through functional binding with the homing receptor E-selectin

Exosomes are tiny vesicles released by cells that carry communications to local and distant locations. Emerging research has revealed the role played by integrins found on the surface of exosomes in delivering information once they reach their destination. But until now, little has been known on the initial upstream steps of the migration process. Using biochemical and imaging approaches, we show here that exosomes isolated from both leukemic and healthy hematopoietic stem/progenitor cells can navigate their way from the cell of origin due to the presence of sialyl Lewis X modifications surface glycoproteins. This, in turn, allows binding to E-selectin at distant sites so the exosomes can deliver their messages. We show that when leukemic exosomes were injected into NSG mice, they traveled to the spleen and spine, sites typical of leukemic cell engraftment. This process, however, was inhibited in mice pre-treated with blocking E-selectin antibodies. Significantly, our proteomic analysis found that among the proteins contained within exosomes are signaling proteins, suggesting that exosomes are trying to deliver active cues to recipient cells that potentially alter their physiology. Intriguingly, the work outlined here also suggests that protein cargo can dynamically change upon exosome binding to receptors such as E-selectin, which thereby could alter the impact it has to regulate the physiology of the recipient cells. Furthermore, as an example of how miRNAs contained in exosomes can influence RNA expression in recipient cells, our analysis showed that miRNAs found in KG1a-derived exosomes target tumor suppressing proteins such as PTEN.

Overexpression of miRNA 26a and 26b with MMP-9 are valuable diagnostic biomarkers for colorectal cancer patients

Background: The key role of miRNA expression in incidence and progression of colorectal cancer (CLC) have been developed over the last decade. Materials & methods: A total of 153 subjects were enrolled into two phases: 14 selected miRNAs were first evaluated in 50 subjects, then miR-26a and miR-26b relative expression were further evaluated in 103 subjects and their target protein MMP-9 was measured. Results: miR-26a and -26b showed highly significant overexpression. Both miR-26a and -26b (p < 0.001) had high diagnostic efficacy for CRC. There was a significant increase in serum MMP-9 protein in CRC patients with positive correlation with miR-26a and -26b expression levels (p < 0.001). Conclusion: miRNA 26a and 26b with MMP-9 can be used as diagnostic biomarker for CRC patients.

A Patient with Transverse Colon Cancer Complicated by Cowden Syndrome Administered FOLFOXIRI + Bevacizumab Therapy

Cowden syndrome is characterized by several clinical features related to tumorous lesions primarily consisting of systemic hamartomas. The mutation of a tumor suppressor gene, the PTEN gene, is etiologically involved. As gastrointestinal lesions, polyps of all digestive tracts involving the esophagus to rectum develop. In patients with Cowden syndrome, the risk of colorectal cancer may increase. However, the characteristics of colorectal cancer in these patients remain to be clarified and sufficient findings regarding chemotherapy have not been obtained. A 39-year-old man was treated with a colonic stent for colitis obstructive due to circumferential transverse colon carcinoma. After decompression, elective extended laparoscopic right hemicolectomy was performed. Preoperative systemic detailed examination revealed characteristic dermal/mucosal findings, polyposis of the upper digestive tract, and a thyroid tumor. On PTEN gene sequencing, a mutation was detected at codon 130 of exon 5, leading to a diagnosis of Cowden syndrome. Postoperative adjuvant chemotherapy was performed for 6 months, but recurrent peritoneal dissemination was observed 1 month after its completion. FOLFOXIRI + bevacizumab therapy was started. Transiently, a partial response was achieved in peritoneally disseminated nodes according to the RECIST. There was no increase in the volume of cancerous ascites. However, an increase in the volume of ascites and local relapse were noted at the completion of the tenth course. The regimen was switched to FOLFIRI + panitumumab, but peritoneal dissemination exacerbated and the patient died 18 months after surgery.

Multiomics Study of a Novel Naturally Derived Small Molecule, NSC772864, as a Potential Inhibitor of Proto-Oncogenes Regulating Cell Cycle Progression in Colorectal Cancer

Colorectal cancer (CRC) is one of the most prevalent malignant tumors, and it contributes to high numbers of deaths globally. Although advances in understanding CRC molecular mechanisms have shed significant light on its pathogenicity, current treatment options, including combined chemotherapy and molecular-targeted agents, are still limited due to resistance, with almost 25% of patients developing distant metastasis. Therefore, identifying novel biomarkers for early diagnosis is crucial, as they will also influence strategies for new targeted therapies. The proto-oncogene, c-Met, a tyrosine kinase that promotes cell proliferation, motility, and invasion; c-MYC, a transcription factor associated with the modulation of the cell cycle, proliferation, apoptosis; and cyclin D1 (CCND1), an essential regulatory protein in the cell cycle, all play crucial roles in cancer progression. In the present study, we explored computational simulations through bioinformatics analysis and identified the overexpression of c-Met/GSK3β/MYC/CCND1 oncogenic signatures that were associated with cancer progression, drug resistance, metastasis, and poor clinical outcomes in CRC. We further demonstrated the anticancer activities of our newly synthesized quinoline-derived compound, NSC772864, against panels of the National Cancer Institute's human CRC cell lines. The compound exhibited cytotoxic activities against various CRC cell lines. Using target prediction tools, we found that c-Met/GSK3β/MYC/CCND1 were target genes for the NSC772864 compound. Subsequently, we performed in silico molecular docking to investigate protein-ligand interactions and discovered that NSC772864 exhibited higher binding affinities with these oncogenes compared to FDA-approved drugs. These findings strongly suggest that NSC772864 is a novel and potential antiCRC agent.

Cellular microRNAs correlate with clinical parameters in multiple injury patients

INTRODUCTION

The pathophysiology of the inflammatory response after major trauma is complex, and the magnitude correlates with severity of tissue injury and outcomes. Study of infection-mediated immune pathways has demonstrated that cellular microRNAs may modulate the inflammatory response. The authors hypothesize that the expression of microRNAs would correlate to complicated recoveries in polytrauma patients (PtPs).

METHODS

Polytrauma patients enrolled in the prospective observational Tissue and Data Acquisition Protocol with Injury Severity Score of >15 were selected for this study. Polytrauma patients were divided into complicated recoveries and uncomplicated recovery groups. Polytrauma patients' blood samples were obtained at the time of admission (T0). Established biomarkers of systemic inflammation, including cytokines and chemokines, were measured using multiplexed Luminex-based methods, and novel microRNAs were measured in plasma samples using multiplex RNA hybridization.

RESULTS

Polytrauma patients (n = 180) had high Injury Severity Score (26 [20-34]) and complicated recovery rate of 33%. MicroRNAs were lower in PtPs at T0 compared with healthy controls, and bivariate analysis demonstrated that variations of microRNAs correlated with age, race, comorbidities, venous thromboembolism, pulmonary complications, complicated recovery, and mortality. Positive correlations were noted between microRNAs and interleukin 10, vascular endothelial growth factor, Acute Physiology and Chronic Health Evaluation, and Sequential Organ Failure Assessment scores. Multivariable Lasso regression analysis of predictors of complicated recovery based on microRNAs, cytokines, and chemokines revealed that miR-21-3p and monocyte chemoattractant protein-1 were predictive of complicated recovery with an area under the curve of 0.78.

CONCLUSION

Systemic microRNAs were associated with poor outcomes in PtPs, and results are consistent with previously described trends in critically ill patients. These early biomarkers of inflammation might provide predictive utility in early complicated recovery diagnosis and prognosis. Because of their potential to regulate immune responses, microRNAs may provide therapeutic targets for immunomodulation.

LEVEL OF EVIDENCE

Diagnostic Tests/Criteria; Level II.

The Insulin-like Growth Factor System and Colorectal Cancer

Insulin-like growth factors (IGFs) are peptides which exert mitogenic, endocrine and cytokine activities. Together with their receptors, binding proteins and associated molecules, they participate in numerous pathophysiological processes, including cancer development. Colorectal cancer (CRC) is a disease with high incidence and mortality rates worldwide, whose etiology usually represents a combination of the environmental and genetic factors. IGFs are most often increased in CRC, enabling excessive autocrine/paracrine stimulation of the cell growth. Overexpression or increased activation/accessibility of IGF receptors is a coinciding step which transmits IGF-related signals. A number of molecules and biochemical mechanisms exert modulatory effects shaping the final outcome of the IGF-stimulated processes, frequently leading to neoplastic transformation in the case of irreparable disbalance. The IGF system and related molecules and pathways which participate in the development of CRC are the focus of this review.

Screening and identification of immune-related genes for immunotherapy and prognostic assessment in colorectal cancer patients

Background

Increasing evidence indicates that the immune microenvironment plays a key role in the genesis and progression of colorectal cancer (CRC). This study aimed to establish an immune-related gene (IRG) signature and determine its clinical prognostic value in patients with CRC.

Methods

The RNA sequencing and associated clinical data of CRC were downloaded from The Cancer Genome Atlas (TCGA) database. We then screened for differentially expressed IRGs by intersecting with IRGs obtained from the Immunology Database and Analysis Portal. Functional enrichment analyses were carried out to determine the potential biological functions and pathways of the IRGs. We also explored the specific molecular mechanisms of the IRGs by constructing regulatory networks. Prognostic IRGs were obtained by LASSO regression analysis, and subsequently, gene models were constructed in the TCGA dataset to confirm the predictive capacity of these IRGs. Finally, we used the TIMER tool to assess the immune properties of prognostic IRGs and correlate them with immune cells.

Results

We identified 409 differentially expressed IRGs in patients with CRC. Kyoto Encyclopaedia of Genes and Genomes and Gene Ontology enrichment analyses suggested that these differentially expressed IRGs were significantly related to 102 cancer signalling pathways and various biological functions. Based on the prediction and interaction results, we obtained 59 TF–IRG, 48 miRNA–IRG, and 214 drug–IRG interaction networks for CRC. Four prognostic genes (POMC, TNFRSF19, FGF2, and SCG2) were developed by integrating 47 survival-related IRGs and 42 characteristic CRC genes. The results of gene model showed that patients in the low risk group had better survival outcomes compared to those in the high risk group. The expression of POMC, TNFRSF19, FGF2, and SCG2 was significantly correlated with immune cells.

Conclusion

This study identified some valid IRGs, and these findings can provide strong evidence for precision immunotherapy in patients with CRC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-022-01329-2.

miRNAs as cornerstones in colorectal cancer pathogenesis and resistance to therapy: A spotlight on signaling pathways interplay - A review

Colorectal cancer (CRC) is the world's third most prevalent cancer and the main cause of cancer-related mortality. A lot of work has been put into improving CRC patients' clinical care, including the development of more effective methods and wide biomarkers variety for prognostic, and diagnostic purposes. MicroRNAs (miRNAs) regulate a variety of cellular processes and play a significant role in the CRC progression and spread via controlling their target gene expression by translation inhibition or mRNA degradation. Consequently, dysregulation and disruption in their function, miRNAs are linked to CRC malignant pathogenesis by controlling several cellular processes involved in the CRC. These cellular processes include increased proliferative and invasive capacity, cell cycle aberration, evasion of apoptosis, enhanced EMT, promotion of angiogenesis and metastasis, and decreased sensitivity to major treatments. The miRNAs control cellular processes in CRC via regulation of pathways such as Wnt/β-catenin signaling, PTEN/AKT/mTOR axis, KRAS, TGFb signaling, VEGFR, EGFR, and P53. Hence, the goal of this review was to review miRNA biogenesis and present an updated summary of oncogenic and tumor suppressor (TS) miRNAs and their potential implication in CRC pathogenesis and responses to chemotherapy and radiotherapy. We also summarise the biological importance and clinical applications of miRNAs in the CRC.

Discovering Innate Driver Variants for Risk Assessment of Early Colorectal Cancer Metastasis

Metastasis is the main fatal cause of colorectal cancer (CRC). Although enormous efforts have been made to date to identify biomarkers associated with metastasis, there is still a huge gap to translate these efforts into effective clinical applications due to the poor consistency of biomarkers in dealing with the genetic heterogeneity of CRCs. In this study, a small cohort of eight CRC patients was recruited, from whom we collected cancer, paracancer, and normal tissues simultaneously and performed whole-exome sequencing. Given the exomes, a novel statistical parameter LIP was introduced to quantitatively measure the local invasion power for every somatic and germline mutation, whereby we affirmed that the innate germline mutations instead of somatic mutations might serve as the major driving force in promoting local invasion. Furthermore, via bioinformatic analyses of big data derived from the public zone, we identified ten potential driver variants that likely urged the local invasion of tumor cells into nearby tissue. Of them, six corresponding genes were new to CRC metastasis. In addition, a metastasis resister variant was also identified. Based on these eleven variants, we constructed a logistic regression model for rapid risk assessment of early metastasis, which was also deployed as an online server, AmetaRisk (http://www.bio-add.org/AmetaRisk). In summary, we made a valuable attempt in this study to exome-wide explore the genetic driving force to local invasion, which provides new insights into the mechanistic understanding of metastasis. Furthermore, the risk assessment model can assist in prioritizing therapeutic regimens in clinics and discovering new drug targets, and thus substantially increase the survival rate of CRC patients.

HypoxaMIRs: Key Regulators of Hallmarks of Colorectal Cancer

Hypoxia in cancer is a thoroughly studied phenomenon, and the logical cause of the reduction in oxygen tension is tumor growth itself. While sustained hypoxia leads to death by necrosis in cells, there is an exquisitely regulated mechanism that rescues hypoxic cells from their fatal fate. The accumulation in the cytoplasm of the transcription factor HIF-1α, which, under normoxic conditions, is marked for degradation by a group of oxygen-sensing proteins known as prolyl hydroxylases (PHDs) in association with the von Hippel-Lindau anti-oncogene (VHL) is critical for the cell, as it regulates different mechanisms through the genes it induces. A group of microRNAs whose expression is regulated by HIF, collectively called hypoxaMIRs, have been recognized. In this review, we deal with the hypoxaMIRs that have been shown to be expressed in colorectal cancer. Subsequently, using data mining, we analyze a panel of hypoxaMIRs expressed in both normal and tumor tissues obtained from TCGA. Finally, we assess the impact of these hypoxaMIRs on cancer hallmarks through their target genes.

MiR-26a-5p as a useful therapeutic target for upper tract urothelial carcinoma by regulating WNT5A/β-catenin signaling

The role of miRNAs in cancer and their possible function as therapeutic agents are interesting and needed further investigation. The miR-26a-5p had been demonstrated as a tumor suppressor in various cancers. However, the importance of miR-26a-5p regulation in upper tract urothelial carcinoma (UTUC) remains unclear. Here, we aimed to explore the miR-26a-5p expression in UTUC tissues and to identify its regulatory targets and signal network involved in UTUC tumorigenesis. The miR-26a-5p expression was validated by quantitative real-time polymerase chain reaction (qPCR) using renal pelvis tissue samples from 22 patients who were diagnosed with UTUC and 64 cases of renal pelvis tissue microarray using in situ hybridization staining. BFTC-909 UTUC cells were used to examine the effects of miR-26a-5p genetic delivery on proliferation, migration and expression of epithelial-to-mesenchymal transition (EMT) markers. MiR-26a-5p was significantly down-regulated in UTUC tumors compared to adjacent normal tissue and was decreased with histological grades. Moreover, restoration of miR-26a-5p showed inhibition effects on proliferation and migration of BFTC-909 cells. In addition, miR-26a-5p delivery regulated the EMT marker expression and inhibited WNT5A/β-catenin signaling and expression of downstream molecules including NF-κB and MMP-9 in BFTC-909 cells. This study demonstrated that miR-26a-5p restoration may reverse EMT process and regulate WNT5A/β-catenin signaling in UTUC cells. Further studies warranted to explore the potential roles in biomarkers for diagnostics and prognosis, as well as novel therapeutics targets for UTUC treatment.

Period 2 Suppresses the Malignant Cellular Behaviors of Colorectal Cancer Through the Epithelial-Mesenchymal Transformation Process

Introduction

The PER2 (Period circadian regulator 2) gene is related to the circadian clock, and it has been deemed as a suppressor gene in osteosarcoma and lung carcinoma. However, the part of PER2 in CRC (colorectal cancer) needs to be further determined.

Methods

First, we collected clinical samples to detect PER2 expression in CRC. Then, we used cell transfection to knock down PER2 expression in CRC cell lines and performed a series of functional experiments to elucidate the effects of PER2 on CRC cells. We next verified whether PER2 affects the epithelial-mesenchymal transformation (EMT) process in CRC by conducting quantitative real-time PCR and western blotting.

Results

In the research, we revealed that the expression of PER2 decreased in CRC clinical samples. In addition, knocking down PER2 expression caused CRC cells to acquire malignant biological features. Finally, we found that PER2 knockdown may activate the Snail/Slug axis through inhibiting p53, therefore promote the activation of the EMT pathway.

Conclusion

In conclusion, low PER2 expression reinforces migration and activates EMT in CRC, suggesting that PER2 is closely related to CRC development and could be used as a potential treatment site in the clinic.

Investigation of miRNA expression profiles using cohort samples reveals potential early detectability of colorectal cancers by serum miR-26a-5p before clinical diagnosis

Previous studies have investigated the usefulness of microRNA (miRNA/miR) expression data for the early detection of colorectal cancer (CRC). However, limited data are available regarding miRNAs that detect CRC before clinical diagnoses. Accordingly, the present study investigated the early detectability of CRC by miRNAs using the preserved serum samples of the cohort participants affected with CRC within 2 years of study enrollment. First, the significant miRNAs were revealed using clinical CRC samples for a (seven early CRCs and seven controls) microarray analysis based on significance analysis of microarrays. Next, replicability was verified by reverse transcription-quantitative (RT-q)PCR (eight early CRCs and eight controls, together with 12 CRCs and 12 controls). Finally, early detectability was tested using the cohort samples of Japan Multi-Institutional Collaborative Cohort Study (17 CRCs and 17 controls) to reveal how a certain number of patients developed CRC within 2 years after participation. In the discovery phase, miRNA expression measurements were conducted using a 3D-Gene Human miRNA Oligo Chip for 2,555 miRNAs, and RT-qPCR analyses were performed to validate the replicability. In the first validation set with eight CRCs with early clinical stage and eight age- and gender-matched controls, miR-26a-5p and miR-223-3p demonstrated the highest diagnostic accuracy of area under the curve (AUC)=1.000 (sensitivity and specificity 100%). In an examination of the predictability of CRC incidence using pre-clinical cohort samples, miR-26a-5p demonstrated good predictability of advanced CRC incidence with an AUC of 0.840. Overall, the present study revealed serum miR-26a-5p as a potential early detection marker for CRC.

Long non-coding RNA VPS9D1-AS1 promotes growth of colon adenocarcinoma by sponging miR-1301-3p and CLDN1

Colon adenocarcinoma is a frequent malignancy among all colon cancer types. Long non-coding RNAs (lncRNAs) are involved in the progression of colon adenocarcinoma. This study aimed to uncover the molecular mechanism of VPS9D1-AS1 in regulating colon adenocarcinoma development. Quantitative reverse transcription-polymerase chain reaction (RT-qPCR) revealed that VPS9D1-AS1 expression was markedly upregulated in colon adenocarcinoma tissues and cell lines. Cell functional experiments showed that knockdown of VPS9D1-AS1 repressed the growth and invasion of colon adenocarcinoma cells but upregulated cell apoptosis. In addition, we confirmed the interaction of VPS9D1-AS1-miR-1301-3p-CLDN1 using a luciferase assay. Downregulation of miR-1301-3p promoted the progression of colon adenocarcinoma cells. In conclusion, VPS9D1-AS1 facilitated cell growth and suppressed apoptosis of colon adenocarcinoma cells by sponging miR-1301-3p and upregulating CLDN1, which may be effective therapeutic strategies for patients with colon adenocarcinoma.

Ascites in ovarian cancer: MicroRNA deregulations and their potential roles in ovarian carcinogenesis

Ovarian cancer comprises the most lethal gynecologic malignancy and is accompanied by the high potential for the incidence of metastasis, recurrence and chemotherapy resistance, often associated with a formation of ascitic fluid. The differentially expressed ascites-derived microRNAs may be linked to ovarian carcinogenesis. The article focuses on a number of miRNAs that share a common expression pattern as determined by independent studies using ascites samples and with regard to their functions and outcomes in experimental and clinical investigations.Let-7b and miR-143 have featured as tumor suppressors in ovarian cancer, which is in line with data on other types of cancer. Although two miRNAs, i.e. miR-26a-5p and miR-145-5p, act principally as tumor suppressor miRNAs, they occasionally exhibit oncogenic roles. The performance of miR-95-3p, upregulated in ascites, is open to debate given the current lack of supportive data on ovarian cancer; however, data on other cancers indicates its probable oncogenic role. Different findings have been reported for miR-182-5p and miR-200c-3p; in addition to their presumed oncogenic roles, contrasting findings have indicated their ambivalent functions. Further research is required for the identification and evaluation of the potential of specific miRNAs in the diagnosis, prediction, treatment and outcomes of ovarian cancer patients.

Attacking the PI3K/Akt/mTOR signaling pathway for targeted therapeutic treatment in human cancer

Cancer is the second leading cause of human death globally. PI3K/Akt/mTOR signaling is one of the most frequently dysregulated signaling pathways observed in cancer patients that plays crucial roles in promoting tumor initiation, progression and therapy responses. This is largely due to that PI3K/Akt/mTOR signaling is indispensable for many cellular biological processes, including cell growth, metastasis, survival, metabolism, and others. As such, small molecule inhibitors targeting major kinase components of the PI3K/Akt/mTOR signaling pathway have drawn extensive attention and been developed and evaluated in preclinical models and clinical trials. Targeting a single kinase component within this signaling usually causes growth arrest rather than apoptosis associated with toxicity-induced adverse effects in patients. Combination therapies including PI3K/Akt/mTOR inhibitors show improved patient response and clinical outcome, albeit developed resistance has been reported. In this review, we focus on revealing the mechanisms leading to the hyperactivation of PI3K/Akt/mTOR signaling in cancer and summarizing efforts for developing PI3K/Akt/mTOR inhibitors as either mono-therapy or combination therapy in different cancer settings. We hope that this review will facilitate further understanding of the regulatory mechanisms governing dysregulation of PI3K/Akt/mTOR oncogenic signaling in cancer and provide insights into possible future directions for targeted therapeutic regimen for cancer treatment, by developing new agents, drug delivery systems, or combination regimen to target the PI3K/Akt/mTOR signaling pathway. This information will also provide effective patient stratification strategy to improve the patient response and clinical outcome for cancer patients with deregulated PI3K/Akt/mTOR signaling.

Hallmark microRNA signature in liquid biopsy identifies hepatocellular carcinoma and differentiates it from liver metastasis

Purpose: This study aims to develop a liquid biopsy assay to identify HCC and differentially diagnose hepatocellular carcinoma (HCC) from colorectal carcinoma (CRC) liver metastasis. Methods: Thirty-two microRNAs (“HallMark-32” panel) were designed to target the ten cancer hallmarks in HCC. Quantitative PCR and supervised machine learning models were applied to develop an HCC-specific diagnostic model. One hundred thirty-three plasma samples from intermediate-stage HCC patients, colorectal cancer (CRC) patients with liver metastasis, and healthy individuals were examined. Results: Six differentially expressed microRNAs (“Signature-Six” panel) were identified after comparing HCC and healthy individuals. The microRNA miR-221-3p, miR-223-3p, miR-26a-5p, and miR-30c-5p were significantly down-regulated in the plasma of HCC samples, while miR-365a-3p and miR-423-3p were significantly up-regulated. Machine learning models combined with HallMark-32 and Signature-Six panels demonstrated promising performance with an AUC of 0.85-0.96 (p ≤ 0.018) and 0.84-0.93 (p ≤ 0.021), respectively. Further modeling improvement by adjusting sample quality variation in the HallMark-32 panel boosted the accuracy to 95% ± 0.01 and AUC to 0.991 (95% CI 0.96-1, p = 0.001), respectively. Even in alpha fetoprotein (AFP)-negative (< 20ng/mL) HCC samples, HallMark-32 still achieved 100% sensitivity in identifying HCC. The Cancer Genome Atlas (TCGA, n=372) analysis demonstrated a significant association between HallMark-32 and HCC patient survival. Conclusion: To the best of our knowledge, this is the first report to utilize circulating miRNAs and machine learning to differentiate HCC from CRC liver metastasis. In this setting, HallMark-32 and Signature-Six are promising non-invasive tests for HCC differential diagnosis and distinguishing HCC from healthy individuals.

Cross-talk between non-coding RNAs and PI3K/AKT/mTOR pathway in colorectal cancer

Colorectal cancer (CRC) is the third commonest cancer globally, with metastasis being the reason for cancer-associated mortality. Much is still unknown biochemically about CRC, and with current treatments that are not wholly effective over time, new therapeutics are urgently needed. Emerging evidence has shown the importance of non-coding RNAs such as lncRNAs and miRNAs functions in the development and progression of CRC. However, the exact underlying mechanism of these types of RNAs in CRC is still mostly unknown. PI3K/AKT/mTOR pathway contributes to many cellular processes, and dysregulation of this pathway frequently occurs in cancers. In this review, the authors have mostly focused on the significant non-coding RNAs regulators of the PI3K/AKT/mTOR pathway and their contribution to the development or inhibition of CRC and their potential as diagnostic or therapeutic targets in CRC treatment.

Combination of Metformin, Sodium Oxamate and Doxorubicin Induces Apoptosis and Autophagy in Colorectal Cancer Cells via Downregulation HIF-1α

Colorectal cancer (CRC) is the third leading cause of cancer-related death worldwide in both sexes. Current therapies include surgery, chemotherapy, and targeted therapy; however, prolonged exposure to chemical agents induces toxicity in patients and drug resistance. So, we implemented a therapeutic strategy based on the combination of doxorubicin, metformin, and sodium oxamate called triple therapy (Tt). We found that Tt significantly reduced proliferation by inhibiting the mTOR/AKT pathway and promoted apoptosis and autophagy in CRC derived cells compared with doxorubicin. Several autophagy genes were assessed by western blot; ULK1, ATG4, and LC3 II were overexpressed by Tt. Interestingly, ULK1 was the only one autophagy-related protein gradually overexpressed during Tt administration. Thus, we assumed that there was a post-transcriptional mechanism mediating by microRNAs that regulate UKL1 expression during autophagy activation. Through bioinformatics approaches, we ascertained that ULK1 could be targeted by mir-26a, which is overexpressed in advanced stages of CRC. In vitro experiments revealed that overexpression of mir-26a decreased significantly ULK1, mRNA, and protein expression. Contrariwise, the Tt recovered ULK1 expression by mir-26a decrease. Due to triple therapy repressed mir-26a expression, we hypothesized this drug combination could be involved in mir-26a transcription regulation. Consequently, we analyzed the mir-26a promoter sequence and found two HIF-1α transcription factor recognition sites. We developed two different HIF-1α stabilization models. Both showed mir-26a overexpression and ULK1 reduction in hypoxic conditions. Immunoprecipitation experiments were performed and HIF-1α enrichment was observed in mir-26a promoter. Surprisingly, Tt diminished HIF-1α detection and restored ULK1 mRNA expression. These results reveal an important regulation mechanism controlled by the signaling that activates HIF-1α and that in turn regulates mir-26a transcription.

Long noncoding RNA Linc01296 promotes hepatocellular carcinoma development through regulation of the miR-26a/PTEN axis

Long noncoding RNA 01296 (Lnc01296) is dysregulated in malignant tumors. However, the detailed effect of Linc01296 on hepatocellular carcinoma (HCC) remains largely unknown. In this study, we identified the biological role of Linc01296 in HCC. The levels of Linc01296 in HCC tissues and a panel of cell lines were assessed by quantitative real-time polymerase chain reaction (qRT-PCR). The effects of Linc01296 on HCC progression were explored using a Cell Counting Kit-8 (CCK-8), flow cytometry, migration and Transwell invasion assays. The interactions among Linc01296, miR-26a and PTEN were determined using luciferase, RNA immunoprecipitation (RIP) and Western blot assays. Tumor xenograft models were utilized to confirm the in vivo functional roles of Linc01296 in HCC development. Linc01296 expression was increased in both HCC tissue samples and cell lines. Knockdown of Linc01296 suppressed HCC cell processes, such as proliferation, migration and invasion, and enhanced apoptosis in vitro; these effects were reversed by a miR-26a mimic or PTEN overexpression. Furthermore, knockdown of Linc01296 suppressed HCC growth in vivo. These findings indicated that Linc01296 is involved in HCC progression via regulating miR-26a/PTEN.

Redox Regulation of the Actin Cytoskeleton in Cell Migration and Adhesion: On the Way to a Spatiotemporal View

The actin cytoskeleton of eukaryotic cells is a dynamic, fibrous network that is regulated by the concerted action of actin-binding proteins (ABPs). In particular, rapid polarization of cells in response to internal and external stimuli is fundamental to cell migration and invasion. Various isoforms of ABPs in different tissues equip cells with variable degrees of migratory and adhesive capacities. In addition, regulation of ABPs by posttranslational modifications (PTM) is pivotal to the rapid responsiveness of cells. In this context, phosphorylation of ABPs and its functional consequences have been studied extensively. However, the study of reduction/oxidation (redox) modifications of oxidation-sensitive cysteine and methionine residues of actin, ABPs, adhesion molecules, and signaling proteins regulating actin cytoskeletal dynamics has only recently emerged as a field. The relevance of such protein oxidations to cellular physiology and pathophysiology has remained largely elusive. Importantly, studying protein oxidation spatiotemporally can provide novel insights into localized redox regulation of cellular functions. In this review, we focus on the redox regulation of the actin cytoskeleton, its challenges, and recently developed tools to study its physiological and pathophysiological consequences.

Regulatory role of microRNAs on PTEN signaling

Phosphatase and tensin homolog (PTEN) gene encodes a tumor suppressor protein which is altered in several malignancies. This protein is a negative regulator of the PI3K/AKT signaling. Several transcription factors regulate the expression of PTEN in positive or negative directions. Moreover, numerous microRNAs (miRNAs) have functional interactions with PTEN and inhibit its expression. Suppression of PTEN can attenuate the response of cancer cells to chemotherapeutic agents. Based on the critical role of this tumor suppressor gene, the identification of negative regulators of its expression has practical significance particularly in the prevention and management of cancer. Meanwhile, the interaction between miRNAs and PTEN has functional consequences in non-malignant disorders including myocardial infarction, osteoporosis, cerebral ischemic stroke, and recurrent abortion. In the present review, we describe the role of miRNAs in the regulation of expression and activity of PTEN.

Inhibition of miRNA-152-3p enhances diabetic wound repair via upregulation of PTEN

Diabetic foot ulcer (DFU) is a major complication of diabetes in the elderly population. The aim of this study was to investigate the potential mechanism of DFU at the molecular level and explore a feasible therapy for it. Using data from the Gene Expression Omnibus (GEO) database, we found that phosphatase and tensin homolog (PTEN) is differentially expressed between diabetic patients and those without diabetes. We also found that PTEN expression is regulated by glucose stimulation. In addition, decreased function of human umbilical vein endothelial cells (HUVECs) was found to be associated with reduction of PTEN. We identified microRNA-152-3p (miR-152-3p) to be a putative upstream negative regulator of PTEN, and in vivo and in vitro results indicated that miR-152-3p antagonist could restore HUVEC function and accelerate wound repair. Thus, miR-152-3p-induced downregulation of PTEN appears responsible for the delayed wound healing in DFU, and miR-152-3p inhibition may effectively accelerate wound repair, thereby providing a potential target for DFU therapy.

MicroRNAs that regulate PTEN as potential biomarkers in colorectal cancer: a systematic review

PURPOSE

MicroRNAs (miRNAs) participate in a variety of biological processes, including tumorigenesis, progression, invasion, and drug resistance to multiple cancers. Phosphatase and tensin homolog (PTEN) is a cancer suppressor gene that has been certified to be regulated by miRNAs in various tumors, including colorectal cancer (CRC). In this review, we screened articles focusing on low PTEN expression in CRC, observed the expression of related miRNAs, analyzed their correlation and relationship with clinicopathological features, and discussed the possibility of these miRNAs as prognostic molecules.

METHODS

We conducted a systematic search for articles published in the Web of Science, PubMed and EBSCO databases between January 1, 2002, and July 18, 2019. We identified these studies by using combinations of the following index entries and key words: 'colorectal tumor OR colorectal neoplasm OR colorectal carcinoma OR colorectal cancer OR CRC', 'protein tyrosine phosphatase OR PTEN', and 'microRNA OR MiRNA OR miRNA OR MicroRNA'. Moreover, we evaluated the underlying association between alterations in PTEN and CRC prognosis.

RESULTS

PTEN expression was obviously lower in CRC tissues than in normal mucosa. However, PTEN expression did not differ significantly between adenoma and normal tissues. PTEN tends to be negatively associated with tumor size and metastasis. MiR-21, miR-200a, miR-543, miR-32, miR-92a, miR-26a, miR-106a and miR-181a were correlated with the downregulation of PTEN. MiR-26a, miR-106a and miR-181a were obviously higher in CRC tissues than in normal tissues, while PTEN was downregulated in CRC tissues. Additionally, miRNAs were mainly positively correlated with distant metastasis, followed by TNM stage. The relationship between miRNAs and tumor differentiation is controversial. However, there were no significant differences between miRNAs and either sex or age.

CONCLUSIONS

The loss of PTEN may be a diagnostic factor for CRC patients. The above-mentioned miRNAs may function as oncogenes in CRC and represent potential targets for CRC therapy. However, further prospective clinical studies are necessary.

Overexpression of FYN suppresses the epithelial-to-mesenchymal transition through down-regulating PI3K/AKT pathway in lung adenocarcinoma

BACKGROUND

Tyrosine-protein kinase Fyn (FYN) plays a crucial role in Src family, which participates in the signal transduction of brain nerves and the development and activation of T lymphocytes in physiological conditions. We probed into the roles and mechanisms of FYN in lung adenocarcinoma (LUAD).

METHODS

Cell activity, apoptosis, invasion, and migration were detected by CCK-8, FCM, transwell, and wound-healing assays, respectively. The angiogenesis capacity was evaluated by in vitro angiogenesis test. Relative mRNA and protein expressions were determined by qRT-PCR, Western blot, and immunohistochemistry assays, respectively. Insulin-like growth factors-I (IGF-I) was used as an agonist of PI3K/AKT pathway.

RESULTS

We demonstrated that FYN expression correlated with LUAD prognosis and was down-regulated in LUAD tissues and LUAD cells. Overexpression of FYN suppressed the cell viability, together with invasion and migration abilities of A549 cells. FYN overexpression accelerated the cell apoptosis and reduced the angiogenesis capacity of A549 cells. Overexpression of FYN suppressed E-cadherin, Vimentin, Snail, and PI3K/AKT expressions in A549 cells. High expression level of FYN reduced the migration and invasion capacities of A549 cells via down-regulating the PI3K/AKT pathway.

CONCLUSION

Collectively, our findings reveal that overexpression of FYN inhibits the epithelial-to-mesenchymal transition (EMT) through down-regulating the PI3K/AKT pathway in A549 cells.

Prognostic value of a hypoxia-related microRNA signature in patients with colorectal cancer

Hypoxia has been particularly associated with poor prognosis in cancer patients. Recent studies have suggested that hypoxia-related miRNAs play a critical role in various cancers, including colorectal cancer (CRC). In the present study, we found 52 differentially expressed miRNAs in HT-29 cells under hypoxic conditions versus normoxic conditions by analyzing the profiles of miRNAs. Using Cox model, we developed a hypoxia-related miRNA signature consisting of four miRNAs, which could successfully discriminate high-risk patients in the Cancer Genome Atlas (TCGA) training cohort (n=381). The prognostic value of this signature was further confirmed in the TCGA testing cohort (n=190) and an independent validation cohort composed of formalin-fixed paraffin-embedded clinical CRC samples (n=220), respectively. Multivariable Cox regression and stratified survival analysis revealed this signature was an independent prognostic factor for CRC patients. Time-dependent receiver operating characteristic (ROC) analysis showed that the area under the curve (AUC) of this signature was significantly larger than that of any other clinical risk factors or single miRNA alone. A nomogram was constructed for clinical use, which incorporated both the miRNA signature and clinical risk factors and performed well in the calibration plots. Collectively, this novel hypoxia-related miRNA signature was an independent prognostic factor, and it possessed a stronger predictive power in identifying high-risk CRC patients than currently used clinicopathological features.

TNNT1, negatively regulated by miR-873, promotes the progression of colorectal cancer

BACKGROUND

Troponin T1 (TNNT1) is a subunit of troponin that has been linked to neuromuscular disorder. Recently, it was reported that TNNT1 facilitates the proliferation of breast cancer cells. Interestingly, Cancer Genome Atlas data indicate that its overexpression is associated with an unfavorable prognosis of colorectal cancer (CRC) patients. The present study aimed to explore the expression, function and mechanism of dysregulation of TNNT1 in CRC.

METHODS

Immunohistochemical staining and a real-time polymerase chain reaction were used to compare the expression level of TNNT1 in CRC tissues and adjacent tissues. Western blotting was used to detect the expression of TNNT1 in cell lines. Kaplan-Meier analysis and a chi-squared test were applied to evaluate the potential of TNNT1 to function as a cancer biomarker. RNA interference was used to inhibit TNNT1 expression in CRC cells, followed by detection of cell proliferation, apoptosis, migration and invasion. A luciferase reporter gene assay was used to determine the regulatory relationship between miR-873 and TNNT1.

RESULTS

In the present study, we found that TNNT1 was significantly up-regulated in CRC samples and cell lines. The up-regulation of TNNT1 was also associated with several clinicopathologic features, and its high expression was correlated with an unfavorable prognosis of the patients. Knockdown of TNNT1 markedly arrested proliferation, migration and invasion, whereas it also promoted apoptosis. TNNT1 was identified as a target gene of miR-873, and there was a negative correlation among CRC samples.

CONCLUSIONS

In conclusion, we have demonstrated that TNNT1, regulated by miR-873, is an oncogene of CRC associated with patient prognosis.

PTEN in Colorectal Cancer: Shedding Light on Its Role as Predictor and Target

Molecular assessment of colorectal cancer (CRC) is receiving growing attention, beyond RAS and BRAF, because of its influence on prognosis and prediction in cancer treatment. PTEN (phosphatase and tensin homologue), a tumor suppressor, regulating cell division and apoptosis, has been explored, and significant evidence suggests a role in cetuximab and panitumumab resistance linked to the epidermal growth factor receptor (EGFR) signal transduction pathway. Factors influencing PTEN activity should be analyzed to develop strategies to maximize the tumor suppressor role and to improve tumor response to cancer treatment. Therefore, an in-depth knowledge of the PI3K-Akt pathway—one of the major cancer survival pathways—and the role of PTEN—a major brake of this pathway—is essential in the era of precision medicine. The purpose of this literature review is to summarize the role of PTEN as a predictive factor and possible therapeutic target in CRC, focusing on ongoing studies and the possible implications in clinical practice.

miR- 26a Sensitizes Melanoma Cells To Dabrafenib Via Targeting HMGB1-Dependent Autophagy Pathways

Background

Melanoma is known as the most aggressive and lethal type of cutaneous cancer due to its rapid development of drug resistance to chemotherapy drugs.

Methods

In our study, we conducted a variety of studies, including quantitative PCR, Western blot, and autophagy and apoptosis assays to investigate the involvement of miR-26a and HMGB1 in modulation of dabrafenib sensitivity in human melanoma cell lines.

Results

Our studies revealed that the expressions of miR-26a and HMGB1 were altered in two melanoma cell lines after dabrafenib treatment. Additionally, dabrafenib caused autophagy in melanoma and this autophagic process was regulated by miR-26a via modifying HMGB1 expression. Furthermore, silencing HMGB1-inhibited autophagy induced by dabrafenib in melanoma cells. Last, we verified that treatment with a miR-26a mimic and HMGB1 shRNA could increase the efficacy of dabrafenib in melanoma cells.

Conclusion

Taken together, we showed that miR-26a is involved in the regulation of dabrafenib efficacy via a HMGB1-dependent autophagy pathway in melanoma cells. These results shed light on a novel treatment for conventional dabrafenib-based chemotherapy for melanoma.