Gastric cancer (GC) is a common malignancy and frequent cause of cancer-related death. Long non-coding RNAs (lncRNAs) have emerged as important regulators and tissue-specific biomarkers of multiple cancers, including GC. Recent evidence has indicated that the novel lncRNA LINC01133 plays an important role in cancer progression and metastasis. However, its function and molecular mechanism in GC remain largely unknown. LINC01133 expression was detected in 200 GC and matched non-cancerous tissues by quantitative reverse transcription PCR. Gain- and loss-of-function experiments were conducted to investigate the biological functions of LINC01133 both in vitro and in vivo. Insights into the underlying mechanisms of competitive endogenous RNAs (ceRNAs) were determined by bioinformatics analysis, dual-luciferase reporter assays, quantitative PCR arrays, TOPFlash/FOPFlash reporter assay, luciferase assay, and rescue experiments. LINC01133 was downregulated in GC tissues and cell lines, and its low expression positively correlated with GC progression and metastasis. Functionally, LINC01133 depletion promoted cell proliferation, migration, and the epithelial–mesenchymal transition (EMT) in GC cells, whereas LINC01133 overexpression resulted in the opposite effects both in vitro and in vivo. Bioinformatics analysis and luciferase assays revealed that miR-106a-3p was a direct target of LINC01133, which functioned as a ceRNA in regulating GC metastasis. Mechanistic analysis demonstrated that miR-106a-3p specifically targeted the adenomatous polyposis coli (APC) gene, and LINC01133/miR-106a-3p suppressed the EMT and metastasis by inactivating the Wnt/β-catenin pathway in an APC-dependent manner. Our findings suggest that reduced expression of LINC01133 is associated with aggressive tumor phenotypes and poor patient outcomes in GC. LINC01133 inhibits GC progression and metastasis by acting as a ceRNA for miR-106a-3p to regulate APC expression and the Wnt/β-catenin pathway, suggesting that LINC01133 may serve as a potential prognostic biomarker and anti-metastatic therapeutic target for GC.

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LINC01133 as ceRNA inhibits gastric cancer progression by sponging miR-106a-3p to regulate APC expression and the Wnt/β-catenin pathway.

Melanoma as the most major skin malignancy has attracted much attention, so far. Although a successful therapeutic strategy requires an accurate understanding of the precise mechanisms for the initiation and progression of the melanoma. Several types of cell death mechanisms have recently been identified along with conventional cell death mechanisms such as apoptosis and necrosis. Among those mechanisms, necroptosis, anoikis, ferroptosis, and autophagy may be considered to have remarkable modulatory impacts on melanoma. In the present review, we explain the mechanisms of cell death signaling pathways related to autophagy, ferroptosis, anoikis, necroptosis, and reticulum endoplasmic stress in cells and describe how those mechanisms transduce signals in melanoma cells. Meanwhile, we describe how we can modulate those mechanisms to eliminate melanoma.

Autophagy, Anoikis, Ferroptosis, Necroptosis, and Endoplasmic Reticulum Stress: Potential Applications in Melanoma Therapy

The attachment of cells to the extracellular matrix (ECM) is the hallmark of structure-function stability and well-being ECM detachment in localized tumors precedes abnormal dissemination of tumor cells culminating in metastasis Programmed cell death (PCD) is activated during tumorigenesis to clear off ECM-detached cells through "anoikis" However, cancer cells develop several mechanisms for abrogating anoikis, thus promoting their invasiveness and metastasis Specific factors, such as growth proteins, pH, transcriptional signaling pathways, and oxidative stress, have been reported as drivers of anoikis resistance, thus enhancing cancer proliferation and metastasis Recent studies highlighted the key contributions of metabolic pathways, enabling the cells to bypass anoikis Therefore, understanding the mechanisms driving anoikis resistance could help to counteract tumor progression and prevent metastasis This review elucidates the dynamics employed by cancer cells to impede anoikis, thus promoting proliferation, invasion, and metastasis In addition, the authors have discussed other metabolic intermediates (especially amino acids and nucleotides) that are less explored, which could be crucial for anoikis resistance and metastasis

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Mechanisms for Modulating Anoikis Resistance in Cancer and the Relevance of Metabolic Reprogramming.

Clear cell renal cell carcinoma (ccRCC) is the third most common urological cancer, and it has the highest mortality rate. The increasing drug resistance of metastatic ccRCC has resulted in the search for new biomarkers. Epigenetic regulatory mechanisms, such as genome-wide DNA methylation and inhibition of protein translation by interaction of microRNA (miRNA) with its target messenger RNA (mRNA), are deeply involved in the pathogenesis of human cancers, including ccRCC, and may be used in its diagnosis and prognosis. Here, we review oncogenic and oncosuppressive miRNAs, their putative target genes, and the crucial pathways they are involved in. The contradictory behavior of a number of miRNAs, such as suppressive and anti-metastatic miRNAs with oncogenic potential (for example, miR-99a, miR-106a, miR-125b, miR-144, miR-203, miR-378), is examined. miRNAs that contribute mostly to important pathways and processes in ccRCC, for instance, PI3K/AKT/mTOR, Wnt-β, histone modification, and chromatin remodeling, are discussed in detail. We also separately consider their participation in crucial oncogenic processes, such as hypoxia and angiogenesis, metastasis, and epithelial-mesenchymal transition (EMT). The review also considers the interactions of long non-coding RNAs (lncRNAs) and miRNAs of significance in ccRCC. Recent advances in the understanding of the role of hypermethylated miRNA genes in ccRCC and their usefulness as biomarkers are reviewed based on our own data and those available in the literature. Finally, new data and perspectives concerning the clinical applications of miRNAs in the diagnosis, prognosis, and treatment of ccRCC are discussed.

/pdf/molecular-mechanisms-in-clear-cell-renal-cell-carcinoma-role-i1hqojbxqk.pdf

Molecular Mechanisms in Clear Cell Renal Cell Carcinoma: Role of miRNAs and Hypermethylated miRNA Genes in Crucial Oncogenic Pathways and Processes.

Gastric cancer (GC) is one of the most pernicious tumors that seriously harm human healthcare. GC metastasis is one of the prime cause of failed cancer treatment, but correlation between N6-methyladenosine (m6A) and GC metastasis was less reported.Methylated RNA immunoprecipitation sequencing (MeRIP-seq) of GC tissues was conducted. Quantitative real-time PCR (qRT-PCR), western blotting and immunohistochemistry (IHC) were taken to determine the expression of ALKBH5 in GC tissues and cell lines. RNA-seq together with MeRIP-qRT-PCR was used to screen the target gene of ALKBH5. RNA pulldown, mass spectrometry and RNA immunoprecipitation (RIP) were used to search the "reader" protein of target gene. The mechanism was also validated via a tail vein injection method for lung metastasis model.Decreased expression of ALKBH5 was detected in GC samples, and it was correlated with clinical tumor distal metastasis and lymph node metastasis. ALKBH5 interference promoted metastasis of GC cells and this effect was closely related to the demethylase activity of ALKBH5. PKMYT1, as a downstream target of ALKBH5, promoted invasion and migration in GC. Caused by ALKBH5 knockdown or its demethylase activity mutation, upregulated expression of PKMYT1 indicated that ALKBH5 modulates expression of PKMYT1 in an m6A-dependent manner. IGF2BP3 helped stabilize the mRNA stability of PKMYT1 via its m6A modification site.This study established an ALKBH5-PKMYT1-IGF2BP3 regulation system in metastasis, representing a new therapeutic target for GC metastasis. 

/pdf/demethylase-alkbh5-suppresses-invasion-of-gastric-cancer-via-4bqocp51.pdf

Demethylase ALKBH5 suppresses invasion of gastric cancer via PKMYT1 m6A modification

MicroRNA-106a-5p (MiR-106a-5p), a small non-coding RNA, has been reported to be downregulated in astrocytoma, osteosarcoma and colorectal cancer. However, the expression levels and biological function in renal cell carcinoma (RCC) have not been studied yet. In this study, we found that the miR-106a-5p was significantly downregulated in RCC tissues and cell lines, and that overexpression of miR-106a-5p led to decreased cell metastasis ability in a xenograft model. Inhibition of miR-106a-5p in RCC cell lines altered the cell migration, invasion and wound healing abilities. Mechanistic studies demonstrated that miR-106a-5p directly bound to the 3'-UTR of the PAK5 mRNA and mediated a decrease in the protein expression of PAK5. We further proved that PAK5 protein levels were negatively correlated with the miR-106a-5p expression in both patient samples and xenograft model. In epigenetics, methylation specific PCR experiments indicated that the upstream gene promoter of miR-106a-5p was hypermethylated in RCC, which might be responsible for its downregulation. Our findings suggested that miR-106a-5p might be a potential gene therapy target for the treatment of RCC metastasis.

/pdf/mir-106a-5p-inhibits-the-cell-migration-and-invasion-of-4ppl6f07hc.pdf

MiR-106a-5p inhibits the cell migration and invasion of renal cell carcinoma through targeting PAK5

N6-methyladenosine (m6A) RNA methylation is profoundly involved in epigenetic regulation, especially for carcinogenesis and tumor progression. Mounting evidence suggests that methyltransferase METTL3 regulates malignant behaviors of gastric cancer (GC). However, the clinical significance and biological implication of SPHK2 and its related m6A modification in GC remain unclear. In this study, quantitative real-time PCR (qRT-PCR), western blot and immunohistochemistry were utilized to detect the expression profiles and prognostic significance of SPHK2 in GC. Here, we showed that increased SPHK2 was signified a poor prognosis of GC patients. Phosphorylation and ubiquitination assays were used to investigate the possible mechanisms of SPHK2-mediated KLF2 expression. SPHK2 can promote the phosphorylation of KLF2, which triggers the ubiquitination and degradation of KLF2 protein in GC. Methylated RNA immunoprecipitation (MeRIP) was performed to uncover the m6A modification of SPHK2 mRNA. METTL3 promotes translation of SPHK2 mRNA via an m6A-YTHDF1-dependent manner. Functionally, SPHK2 facilitates GC cell proliferation, migration and invasion by inhibiting KLF2 expression. SPHK2/KLF2 regulates the cell proliferation, migration, and invasion induced by METTL3 in GC. Overall, our findings reveal that METTL3-mediated m6A modification of SPHK2 contributes to GC progression, which extends the understanding of the importance m6A methylation in GC and represents a potential target for GC therapy.

METTL3-mediated m 6 A methylation of SPHK2 promotes gastric cancer progression by targeting KLF2.

p21-activated kinase 5 (PAK5) is involved in several oncogenic signaling pathways and its amplification or overexpression has been found in various types of cancer; however, the pathophysiologic role of PAK5 in cervical cancer (CC) remains elusive. This study aims to elucidate the effects of PAK5 on CC metastasis and its specific regulation mechanism. We performed western blotting and immunohistochemistry (IHC) analysis and found that the expression levels of PAK5 were significantly upregulated in CC cells and tissues. In addition, statistical analysis via IHC showed that increased PAK5 significantly correlated with CC progression. Mn2+-Phos-tag SDS-PAGE, western blotting, immunofluorescence and dual luciferase reporter assays were utilized to determine the involvement of SATB1 in PAK5-mediated epithelial–mesenchymal transition (EMT). We found that PAK5-mediated special AT-rich binding protein-1 (SATB1) phosphorylation on Ser47 initiated EMT cascade and promoted migration and invasion of CC cells. Furthermore, overexpression of PAK5 induced lung metastasis of CC cells in xenograft modes. Taken together, we conclude that PAK5 is a novel prognostic indicator and plays an important role in the CC metastasis.

/pdf/pak5-promotes-the-migration-and-invasion-of-cervical-cancer-4t28c0ze6w.pdf

PAK5 promotes the migration and invasion of cervical cancer cells by phosphorylating SATB1

Hepatocellular carcinoma-related protein-1 (HCRP-1), a subunit of mammalian endosomal sorting complex required for transport-I (ESCRT-I), is frequently downregulated in various kinds of malignant tumors. The role of HCRP-1 in colorectal cancer (CRC) remains unknown. We investigate the clinical value of HCRP-1 and its impact on anoikis in CRC. The negative expression of HCRP-1 was significantly correlated with tumor size (P = 0.033), PT status (P = 0.001), TNM stage (P = 0.039), and histological grade (P = 0.01). Univariate and multivariate analyses revealed that HCRP-1 was an independent prognostic factor for CRC (hazard ratio (HR) = 0.237, P < 0.001 for 5-year overall survival). In the in vitro assay, we found that HCRP-1 depletion resulted in cell anoikis resistance. Knockdown of HCRP-1 suppressed Bcl-2 interacting mediator of cell death (BIM) expression, with phosphorylation of AKT and p-FoxO3a, which was reversed by AKT siRNA or AKT inhibitor. Further analysis showed that loss of HCRP-1 obviously increased the activation of EGFR. Inhibition of EGFR blocked si-HCRP1-mediated phosphorylation of EGFR, AKT, FoxO3a, and BIM expression. Moreover, the in vivo results revealed that loss of HCRP-1 promoted cancer metastasis. Our findings implied that reduced HCRP-1 expression in CRC resulted in anoikis resistance and contributed to CRC metastasis and poor prognosis. These data may help design effective therapy targeting HCRP-1 pathway to control colon cancer growth and metastasis.

/pdf/hcrp-1-regulates-egfr-akt-bim-mediated-anoikis-resistance-kc1l09iecc.pdf

HCRP-1 regulates EGFR-AKT-BIM-mediated anoikis resistance and serves as a prognostic marker in human colon cancer.

Sorafenib is a kinase inhibitor that is used as a first-line therapy in advanced hepatocellular carcinoma (HCC) patients. However, the existence of sorafenib resistance has limited its therapeutic effect. Through RNA sequencing, we demonstrated that miR-138-1-3p was downregulated in sorafenib resistant HCC cell lines. This study aimed to investigate the role of miR-138-1-3p in sorafenib resistance of HCC. In this study, quantitative real-time PCR (qPCR) and Western Blot were utilized to detect the levels of PAK5 in sorafenib-resistant HCC cells and parental cells. The biological functions of miR-138-1-3p and PAK5 in sorafenib-resistant cells and their parental cells were explored by cell viability assays and flow cytometric analyses. The mechanisms for the involvement of PAK5 were examined via co-immunoprecipitation (co-IP), immunofluorescence, dual luciferase reporter assay and chromatin immunoprecipitation (ChIP). The effects of miR-138-1-3p and PAK5 on HCC sorafenib resistant characteristics were investigated by a xenotransplantation model. We detected significant down-regulation of miR-138-1-3p and up-regulation of PAK5 in sorafenib-resistance HCC cell lines. Mechanistic studies revealed that miR-138-1-3p reduced the protein expression of PAK5 by directly targeting the 3′-UTR of PAK5 mRNA. In addition, we verified that PAK5 enhanced the phosphorylation and nuclear translocation of β-catenin that increased the transcriptional activity of a multidrug resistance protein ABCB1. PAK5 contributed to the sorafenib resistant characteristics of HCC via β-catenin/ABCB1 signaling pathway. Our findings identified the correlation between miR-138-1-3p and PAK5 and the molecular mechanisms of PAK5-mediated sorafenib resistance in HCC, which provided a potential therapeutic target in advanced HCC patients.

/pdf/microrna-138-1-3p-sensitizes-sorafenib-to-hepatocellular-1ime5b54jq.pdf

Fu-Chun Huo

Papers

MiR-106a-5p inhibits the cell migration and invasion of renal cell carcinoma through targeting PAK5

METTL3-mediated m 6 A methylation of SPHK2 promotes gastric cancer progression by targeting KLF2.

PAK5 promotes the migration and invasion of cervical cancer cells by phosphorylating SATB1

HCRP-1 regulates EGFR-AKT-BIM-mediated anoikis resistance and serves as a prognostic marker in human colon cancer.

MicroRNA-138-1-3p sensitizes sorafenib to hepatocellular carcinoma by targeting PAK5 mediated β-catenin/ABCB1 signaling pathway.