Inhibition of rhotekin exhibits antitumor effects in lung cancer cells

miR-145 as a Potential Biomarker and Therapeutic Target in Patients with Non-Small Cell Lung Cancer

Our previous study found that miR-145 was downregulated in non-small cell lung cancer (NSCLC) tissues and that it could inhibit the cell proliferation in transfected NSCLC cells. In this study, we found that miR-145 was downregulated in NSCLC plasma samples compared to healthy controls. A receiver operating characteristic curve analysis indicated that plasma miR-145 expression was correlated with NSCLC in patient samples. We further revealed that the transfection of miR-145 inhibited the proliferation, migration, and invasion of NSCLC cells. Most importantly, miR-145 significantly delayed the tumor growth in a mouse model of NSCLC. We further identified GOLM1 and RTKN as the direct targets of miR-145. A cohort of paired tumors and adjacent non-malignant lung tissues from NSCLC patients was used to confirm the downregulated expression and diagnostic value of miR-145. The results were highly consistent between our plasma and tissue cohorts, confirming the clinical value of miR-145 in different sample groups. In addition, we also validated the expressions of miR-145, GOLM1, and RTKN using the TCGA database. Our findings suggested that miR-145 is a regulator of NSCLC and it plays an important role in NSCLC progression. This microRNA and its gene targets may serve as potential biomarkers and novel molecular therapeutic targets in NSCLC patients.

The Pharmacological Mechanism of Curcumin against Drug Resistance in Non-Small Cell Lung Cancer: Findings of Network Pharmacology and Bioinformatics Analysis

The pharmacological mechanism of curcumin against drug resistance in non-small cell lung cancer (NSCLC) remains unclear. This study aims to summarize the genes and pathways associated with curcumin action as an adjuvant therapy in NSCLC using network pharmacology, drug-likeness, pharmacokinetics, functional enrichment, protein-protein interaction (PPI) analysis, and molecular docking. Prognostic genes were identified from the curcumin-NSCLC intersection gene set for the following drug sensitivity analysis. Immunotherapy, chemotherapy, and targeted therapy sensitivity analyses were performed using external cohorts (GSE126044 and IMvigor210) and the CellMiner database. 94 curcumin-lung adenocarcinoma (LUAD) hub targets and 41 curcumin-lung squamous cell carcinoma (LUSC) hub targets were identified as prognostic genes. The anticancer effect of curcumin was observed in KEGG pathways involved with lung cancer, cancer therapy, and other cancers. Among the prognostic curcumin-NSCLC intersection genes, 20 LUAD and 8 LUSC genes were correlated with immunotherapy sensitivity in the GSE126044 NSCLC cohort; 30 LUAD and 13 LUSC genes were associated with immunotherapy sensitivity in the IMvigor210 cohort; and 12 LUAD and 13 LUSC genes were related to chemosensitivity in the CellMiner database. Moreover, 3 LUAD and 5 LUSC genes were involved in the response to targeted therapy in the CellMiner database. Curcumin regulates drug sensitivity in NSCLC by interacting with cell cycle, NF-kappa B, MAPK, Th17 cell differentiation signaling pathways, etc. Curcumin in combination with immunotherapy, chemotherapy, or targeted drugs has the potential to be effective for drug-resistant NSCLC. The findings of our study reveal the relevant key signaling pathways and targets of curcumin as an adjuvant therapy in the treatment of NSCLC, thus providing pharmacological evidence for further experimental research.

Potential Non-coding RNAs from Microorganisms and their Therapeutic Use in the Treatment of Different Human Cancers

Cancer therapy describes the treatment of cancer, often with surgery, chemotherapy, and radiotherapy. Additionally, RNA interference (RNAi) is likely to be considered a new emerging, alternative therapeutic approach for silencing/targeting cancer-related genes. RNAi can exert antiproliferative and proapoptotic effects by targeting functional carcinogenic molecules or knocking down gene products of cancer-related genes. However, in contrast to conventional cancer therapies, RNAi based therapy seems to have fewer side effects. Transcription signal sequence and conserved sequence analysis-showed that microorganisms could be a potent source of non-coding RNAs. This review concluded that mapping of RNAi mechanism and RNAi based drug delivery approaches is expected to lead a better prospective of cancer therapy.

The DNA replication regulator MCM6: An emerging cancer biomarker and target

MCM6 is a significant DNA replication regulator that plays a crucial role in sustaining the cell cycle. In many cancer cells, MCM6 expression is enhanced. For example, persistently increased expression of MCM6 promotes the formation, development and progression of hepatocellular carcinoma (HCC). Up- and down-regulation studies have indicated that MCM6 regulates cell cycle, proliferation, metastasis, immune response and the maintenance of the DNA replication system. MCM6 can also regulate downstream signaling such as MEK/ERK thus promoting carcinogenesis. Accordingly, MCM6 may represent a sensitive and specific biomarker to predict adverse progression and poor outcome. Furthermore, inhibition of MCM6 may be an effective cancer treatment. The present review summarizes the latest results on the inactivating and activating functions of MCM6, underlining its function in carcinogenesis. Further studies of the carcinogenic functions of MCM6 may provide novel insight into cancer biology and shed light on new approaches for cancer diagnosis and treatment.

c-MYC-induced long noncoding RNA MEG3 aggravates kidney ischemia-reperfusion injury through activating mitophagy by upregulation of RTKN to trigger the Wnt/β-catenin pathway

Ischemia-reperfusion injury (IRI)-induced acute kidney injury (AKI) is a life-threatening disease. The activation of mitophagy was previously identified to play an important role in IRI. Maternally expressed 3 (MEG3) can promote cerebral IRI and hepatic IRI. The present study was designed to study the role of MEG3 in renal IRI. Renal IRI mice models were established, and HK-2 cells were used to construct the in vitro models of IRI. Hematoxylin-eosin staining assay was applied to reveal IRI-triggered tubular injury. MitoTracker Green FM staining and an ALP kit were employed for detection of mitophagy. TdT-mediated dUTP-biotin nick-end labeling assay was used to reveal cell apoptosis. The results showed that renal cortex of IRI mice contained higher expression of MEG3 than that of sham mice. MEG3 expression was also elevated in HK-2 cells following IRI, suggesting that MEG3 might participate in the development of IRI. Moreover, downregulation of MEG3 inhibited the apoptosis of HK-2 cells after IRI. Mitophagy was activated by IRI, and the inhibition of MEG3 can restore mitophagy activity in IRI-treated HK-2 cells. Mechanistically, we found that MEG3 can bind with miR-145-5p in IRI-treated cells. In addition, rhotekin (RTKN) was verified to serve as a target of miR-145-5p. MEG3 upregulated RTKN expression by binding with miR-145-5p. Further, MEG3 activated the Wnt/β-catenin pathway by upregulation of RTKN. The downstream effector of Wnt/β-catenin pathway, c-MYC, served as the transcription factor to activate MEG3. In conclusion, the positive feedback loop of MEG3/miR-145-5p/RTKN/Wnt/β-catenin/c-MYC promotes renal IRI by activating mitophagy and inducing apoptosis, which might offer a new insight into the therapeutic methods for renal IRI in the future.

Conjoint analysis for hepatic carcinoma with hub genes and multi-slice spiral CT

Hepatic carcinoma (HCC) is a common malignant tumor, with insidious onset and poor prognosis. However, more hub genes associated with hepatocellular carcinoma are unknown. And there are few researches about the conjoint analysis with the hub genes and multi-slice spiral computerized tomography (CT).A total of 100 HCC participates were recruited, who all received the examination of multi-slice spiral CT. Two expression profile data sets (GSE101728 and GSE101685) were downloaded from the Gene Expression Omnibus (GEO) database. GEO2R can perform a command to compare gene expression profiles between groups in order to identify differently expressed genes (DEGs). Functional annotation of DEGs via Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis was made with Database for Annotation, Visualization, and Integrated Discovery (DAVID). Construction and analysis of protein-protein interaction network were performed. Furthermore, the study could mine of hub genes and explore the correlation with the multi-slice CT. Real-time quantitative polymerase chain reaction (RT-qPCR) assay was used the exam the expression of hub genes.A total of 10 genes were identified as hub genes with degrees ≥10. The hub genes (NIMA Related Kinase 2 [NEK2], Anillin Actin Binding Protein [ANLN], DNA Topoisomerase II Alpha [TOP2A], Centromere Protein F [CENPF], Assembly Factor For Spindle Microtubules [ASPM], Cell Division Cycle 20 [CDC20], Cyclin Dependent Kinase 1 [CDK1], Cyclin B1 [CCNB1], Epithelial Cell Transforming 2 [ECT2], Cyclin B2 [CCNB2]) were identified from the Molecular Complex Detection (MCODE) network. These hub genes were highly expressed in HCC tissues, and when these genes were highly expressed, the survival prognosis of HCC patients was poor. The type of CT enhancement was significantly related with the expression of NEK2 (P < .001), ANLN (P < .001), and TOP2A (P = .006).The combination between the gene expression (NEK2, ANLN, and TOP2A) and type of CT enhancement might provide a new idea for future basic research and targeted therapy of HCC.

Functions of Rhotekin, an Effector of Rho GTPase, and Its Binding Partners in Mammals

Rhotekin is an effector protein for small GTPase Rho. This protein consists of a Rho binding domain (RBD), a pleckstrin homology (PH) domain, two proline-rich regions and a C-terminal PDZ (PSD-95, Discs-large, and ZO-1)-binding motif. We, and other groups, have identified various binding partners for Rhotekin and carried out biochemical and cell biological characterization. However, the physiological functions of Rhotekin, per se, are as of yet largely unknown. In this review, we summarize known features of Rhotekin and its binding partners in neuronal tissues and cancer cells.

Silver nanoparticles enhance the apoptotic potential of gemcitabine in human ovarian cancer cells: combination therapy for effective cancer treatment

Background

Gemcitabine (GEM) is widely used as an anticancer agent in several types of solid tumors. Silver nanoparticles (AgNPs) possess unique cytotoxic features and can induce apoptosis in a variety of cancer cells. In this study, we investigated whether the combination of GEM and AgNPs can exert synergistic cytotoxic effects in the human ovarian cancer cell line A2780.

Methods

We synthesized AgNPs using resveratrol as a reducing and stabilizing agent. The synthesized nanomaterials were characterized using various analytical techniques. The anticancer effects of a combined treatment with GEM and AgNPs were evaluated using a series of cellular assays. The expression of pro- and antiapoptotic genes was measured using real-time reverse transcription polymerase chain reaction. Apoptosis was confirmed by TUNEL assay.

Results

In this study, combined treatment with GEM and AgNPs significantly inhibited viability and proliferation in A2780 cells. Moreover, the levels of apoptosis in cells treated with a combination of GEM and AgNPs were significantly higher compared with those in cells treated with GEM or AgNPs alone. Our data suggest that GEM and AgNPs exhibit potent apoptotic activity in human ovarian cancer cells. Combined treatment with GEM and AgNPs showed a significantly higher cytotoxic effect in ovarian cancer cells compared with that induced by either of these agents alone.

Conclusion

Our study demonstrated that the interaction between GEM and AgNPs was cytotoxic in ovarian cancer cells. Combined treatment with GEM and AgNPs caused increased cytotoxicity and apoptosis in A2780 cells. This treatment may have therapeutic potential as targeted therapy for the treatment of ovarian cancer. To our knowledge, this study could provide evidence that AgNPs can enhance responsiveness to GEM in ovarian cancer cells and that AgNPs can potentially be used as chemosensitizing agents in ovarian cancer therapy.

Suppression of CEP55 reduces cell viability and induces apoptosis in human lung cancer

Centrosomal protein 55 (CEP55), identified as a centrosome‑associated protein, has been reported to be involved in human malignancies. However, its biological function in human lung cancer remains largely unknown. In the present study, we firstly analyzed the expression of CEP55 in 20 pairs of lung cancer and matched non‑tumor tissues using quantitative RT‑PCR analysis and found that CEP55 mRNA was significantly increased in lung cancer tissues compared with that in matched tumor‑adjacent tissues. Then we performed a loss‑of‑function assay using lung cancer cell lines A549 and 95D. Functionally, knockdown of CEP55 markedly inhibited cell viability and proliferation ability as determined by MTT and colony formation assays. Moreover, CEP55‑silenced cells were obviously arrested in the G0/G1 phase and presented significant cell apoptosis as determined using flow cytometric analysis. Mechanistically, western blot analysis further revealed that knockdown of CEP55 decreased the expression of CDK4, p21 and Bcl‑2, while it increased the expression of pro‑apoptotic protein, Bad, caspase‑3 and PARP in 95D cells. In conclusion, our data highlight the crucial role of CEP55 in promoting lung cancer cell proliferation in vitro and its inhibition may be a novel therapeutic strategy for lung cancer.

Let-7a inhibits tumor cell growth and metastasis by directly targeting RTKN in human colon cancer

Colorectal cancer (CRC) is the third most common cancer worldwide, with high morbidity. MicroRNAs (miRNAs) are endogenous small RNAs that play important roles in regulating multiple biological and pathologic processes. The differential expression of miRNAs in CRC was first reported in 2003. Accumulated evidence indicates that lethal-7a (let-7a, miRNA) generally functions as a tumor suppressor in several human cancers. However, the role of let-7a in human colon cancer remains unclear. The aim of this study was to investigate the biological functions of let-7a and its potential role in colon cancer. We first discovered that let-7a level was significantly decreased in colon cancer tissues and cell lines (HT-29, HCT-116, LoVo, SW480, and SW620). To explore the effects of let-7a on colon cancer, let-7a over-expressed HCT-116 and SW620 cells were constructed. Further studies demonstrated that over-expressed let-7a could remarkably inhibit HCT-116 and SW620 cell growth and metastasis by directly down-regulating Rhotekin (RTKN). When RTKN was reintroduced into let-7a mimic transfected HCT-116 or SW620 cells, the inhibition effects of let-7a on colon cancer cell growth and metastasis were markedly reversed. In conclusion, our research shows that let-7a can inhibit tumor cell growth and metastasis by directly targeting RTKN in human colon cancer.