circEIF3I Promotes Colorectal Cancer Metastasis by Regulating the miR-328-3p/NCAPH Axis.

Colorectal cancer (CRC) is the most common gastrointestinal malignancy, with its recurrence and metastasis significantly affecting patient survival. Circular RNAs (circRNAs), a novel class of noncoding RNAs, have emerged as crucial contributors to CRC pathogenesis. However, the role of circEIF3I in CRC metastasis remains unclear. Quantitative real-time polymerase chain reaction (qRT-PCR) was applied to assess circEIF3I, microRNA (miR)-328-3p, and NCAPH expression. CRC cell migration and invasion were determined via Transwell assays. Western blot analysis was utilized to define the protein expression of epithelial-mesenchymal transition (EMT) markers and NCAPH. Xenograft tumor was established for exploration into the function of circEIF3I in CRC metastasis to the liver and lung. The binding between miR-328-3p and circEIF3I or NCAPH was predicted through ENCORI or TargetScan platform and ascertained through dual-luciferase reporter assays. circEIF3I and NCAPH expression were found to be elevated in CRC tissues and cells, while miR-328-3p was downregulated. Functionally, circEIF3I knockdown inhibited CRC cell migration, invasion, EMT, and tumor metastasis. Mechanistic analyses revealed that circEIF3I can target miR-328-3p, while NCAPH was targeted by miR-328-3p. Furthermore, circEIF3I facilitated NCAPH expression in CRC cells by sequestering miR-328-3p. Notably, miR-328-3p inhibitor or NCAPH overexpression negated the effects of circEIF3I knockdown on preventing CRC progression in vitro. Taken together, circEIF3I elevated NCAPH expression by sponging miR-328-3p, thereby promoting CRC metastasis. These findings suggest that the circEIF3I/miR-328-3p/NCAPH axis represents a novel therapeutic target for CRC.

Zhao Y ，He Y ，Xiao Z ，Xin L ，Deng M ，Yao M ，Huang G ... -  《-》

The miR-1269a/PCDHGA9/CXCR4/β-catenin pathway promotes colorectal cancer invasion and metastasis.

Colorectal cancer (CRC) is the third most common cancer worldwide and the second leading cause of cancer-related death. This research focuses on investigating the impact and underlying molecular mechanisms of protocadherin gamma subfamily A, 9 (PCDHGA9) on the invasion and metastasis of CRC, aiming to identify more precise molecular markers for the diagnosis and prognosis of CRC. PCDHGA9 expression was detected using quantitative real-time quantitative polymerase chain reaction (RT-qPCR) in 63 pairs of colorectal cancer tissues. Differential gene expression from high-throughput sequencing was analyzed using ingenuity pathway analysis (IPA) to explore the biological functions of PCDHGA9 and its potential regulated genes. Bioinformatics tools were employed to explore potential upstream regulatory microRNAs of PCDHGA9. Dual-luciferase assays were performed to demonstrate the regulation between PCDHGA9 and miR-1269a. Protein mass spectrometry suggested an interaction between PCDHGA9 and HOXA1. JASPAR predicted that HOXA1 may act as a transcription factor of CXCR4. Coimmunoprecipitation, dual-luciferase assays, and nuclear-cytoplasmic fractionation experiments confirmed the molecular mechanism involving PCDHGA9, CXCR4, HOXA1, and β-catenin. Transwell, wound healing, and western blot assays were conducted to confirm the impact of PCDHGA9, miR-1269a, and CXCR4 on the invasion, metastasis, and epithelial-mesenchymal transition (EMT) functions of CRC cells in in vitro experiments. A whole-body fluorescence imaging system was used to evaluate the combined impact of miR-1269a and PCDHGA9 on the invasion and metastasis of CRC in in vivo experiments. The expression of PCDHGA9 was found to be lower in CRC tissues compared with their corresponding adjacent tissues. Low expression of PCDHGA9 potentially correlated with worse prognosis and increased chances of invasion and metastasis in CRC. miR-1269a was highly expressed in CRC tissues and acted as a negative regulator for PCDHGA9, promoting invasion, migration, and EMT of CRC cells. PCDHGA9's interaction with HOXA1 downregulated CXCR4, a transcription factor, leading to accumulation of β-catenin and further promoting invasion, migration, and EMT of CRC cells. PCDHGA9, acting as a tumor suppressor, is downregulated by miR-1269a. The low level of PCDHGA9 activates the Wnt/β-catenin pathway by releasing its interaction with HOXA1, promoting the expression of CXCR4, and causing invasion, migration, and EMT in CRC.

Mei H ，Luo Q ，Weng J ，Hao J ，Cai J ，Zhou R ，Bian C ，Ye Y ，Luo S ，Wen Y ... -  《-》

Circular RNA (circ)_0053277 Contributes to Colorectal Cancer Cell Growth, Angiogenesis, Metastasis and Glycolysis.

Circular RNAs (circRNAs) have been found to be abnormally expressed in many cancers, including colorectal cancer (CRC). Circ_0053277 has been found to mediate CRC malignant processes and may be a key regulator for CRC progression. Therefore, its role and potential molecular mechanism in CRC process deserve further investigation. Quantitative real-time PCR was used to detect the expression levels of circ_0053277, microRNA-520 h (miR-520 h) and hexokinase 1 (HK1). Cell Counting Kit-8, 5-ethynyl-2'-deoxyuridine assay, flow cytometry, wound healing assay, transwell assay, and tube formation assay were used to detect CRC cell proliferation, apoptosis, migration, invasion, and angiogenesis. The protein levels of apoptosis-related markers and HK1 were detected by western blot. The relationship between circ_0053277 and miR-520 h or miR-520 h and HK1 in CRC cells was verified by dual-luciferase reporter assay, RNA immunoprecipitation assay and RNA pull-down assay. Cell glycolysis was assessed by detecting glucose uptake and lactate production. The effect of silenced circ_0053277 on CRC tumor growth was evaluated by xenograft model in vivo. Our study found that circ_0053277 expression was elevated in CRC tissues and cells. Moreover, circ_0053277 knockdown suppressed CRC cell proliferation, angiogenesis, migration and invasion, while promoting apoptosis. In terms of mechanism, circ_0053277 sponged miR-520 h, and HK1 was the target of miR-520 h. Meanwhile, miR-520 h inhibitor reversed the inhibitory effect of circ_0053277 silencing on CRC cell progression, and HK1 overexpression also overturned the suppressive effect of miR-520 h on CRC cell growth, angiogenesis and metastasis. Moreover, circ_0053277 knockdown inhibited the glycolysis of CRC cells by regulating miR-520 h/HK1 pathway. In addition, knockdown of circ_0053277 reduced CRC tumor growth in vivo. Circ_0053277 promoted CRC cell growth, angiogenesis, metastasis and glycolysis by miR-520 h/HK1 pathway, confirming that circ_0053277 might be a potential clinical target for CRC treatment.

Zhuang J ，Song W ，Li M ，Kang D ，Cheng K ... -  《-》

lncRNA SNHG4 enhanced gastric cancer progression by modulating miR-409-3p/CREB1 axis.

Gastric cancer (GC) is a globally common cancer characterized by high incidence and mortality worldwide. Advances in the molecular understanding of GC provide promising targets for GC diagnosis and therapy. Long non-coding RNAs (lncRNAs) and their downstream regulators are regarded to be implicated in the progression of multiple types of malignancies. Studies have shown that the lncRNA small nucleolar RNA host gene 4 (SNHG4) serves as a tumor promoter in various malignancies, while its function in GC has yet to be characterized. Therefore, our study aimed to explore the role and underlying mechanism of SNHG4 in GC. We used qRT-PCR to analyze SNHG4 expression in GC tissues and cells. Kaplan-Meier analysis was used to assess the correlation between SNHG4 expression and the survival rate of GC patients. Cellular function experiments such as CCK-8, BrdU, colony formation, flow cytometry analysis, and transwell were performed to explore the effects of SNHG4 on GC cell proliferation, apoptosis, cell cycle, migration, and invasion. We also established xenograft mouse models to explore the effect of SNHG4 on GC tumor growth. Mechanically, dual luciferase reporter assay was used to verify the interaction between SNHG4 and miR-409-3p and between miR-409-3p and cAMP responsive element binding protein 1 (CREB1). The results indicated that SNHG4 was overexpressed in GC tissues and cell lines, and was linked with poor survival rate of GC patients. SNHG4 promoted GC cell proliferation, migration, and invasion while inhibiting cell apoptosis and cell cycle arrest in vitro. The in vivo experiment indicated that SNHG4 facilitated GC tumor growth. Furthermore, SNHG4 was demonstrated to bind to miR-409-3p. Moreover, CREB1 was directly targeted by miR-409-3p. Rescue assays demonstrated that miR-409-3p deficiency reversed the suppressive impact of SNHG4 knockdown on GC cell malignancy. Additionally, miR-409-3p was also revealed to inhibit GC cell proliferation, migration, and invasion by targeting CREB1. In conclusion, we verified that the SNHG4 promoted GC growth and metastasis by binding to miR-409-3p to upregulate CREB1, which may deepen the understanding of the underlying mechanism in GC development.

Cheng Z ，Hua Y ，Cao Y ，Qin J ... -  《-》

Long non-coding RNA AC105118.1 affects glycolysis to facilitate oxaliplatin resistance in colorectal cancer cells by modulating the miR-378a-3p/KIF26B axis.

Oxaliplatin is a first-line chemotherapy drug for colorectal cancer (CRC), but many patients eventually lose treatment efficacy due to acquired resistance. AC105118.1 is a long non-coding RNA with unknown biological function. This research attempts to probe into the molecular regulatory mechanism of AC105118.1 in CRC oxaliplatin resistance. The expression level of AC105118.1 in CRC tissues and cells was measured based on The Cancer Genome Atlas (TCGA) data and quantitative reverse transcription polymerase chain reaction (qRT-PCR). We utilized dual-luciferase assay and RNA immunoprecipitation to analyze the interaction between AC105118.1, miR-378a-3p, and their downstream target KIF26B. CCK-8, colony formation assay, and flow cytometry were employed to assess the half inhibitory concentration (IC50), cell proliferation, and apoptosis rate of HCT116/L-OHP cells treated with oxaliplatin. The glycolysis evaluation was completed by measuring the extracellular acidification rate (ECAR), glucose consumption, lactate production, and glycolysis-related proteins (HK2, GLUT1, and LDHA). TUNEL staining was used to detect the level of apoptosis. AC105118.1 was specifically upregulated in CRC tissues and cells. AC105118.1 indirectly facilitated the expression of miRNA target gene KIF26B by sequestering miR-378a-3p. In HCT116/L-OHP cells, transfection with si-AC105118.1 resulted in a decrease in glycolysis level, a lower maximum IC50 required for oxaliplatin-treated cells, inhibited cell proliferation, and an increase in apoptosis rate. All of these effects were alleviated when simultaneously transfecting miR-378a-3p inhibitor or oe-KIF26B. Knockdown of AC105118.1 significantly inhibited oxaliplatin resistance to CRC in mice. AC105118.1 facilitates glycolysis and increases CRC cells' resistance to oxaliplatin by targeting the miR-378a-3p/KIF26B axis. The present work shed new insights into the function and mechanism of AC105118.1 in molecular function and suggested that the AC105118.1/miR-378a-3p/KIF26B axis is a promising target for intervening CRC oxaliplatin resistance.

Zhang Y ，Shen Z ，Han X ，Wu Y ，Huang T ... -  《-》