Mn12Ac inhibits the migration, invasion and epithelial-mesenchymal transition of lung cancer cells by downregulating the Wnt/β-catenin and PI3K/AKT signaling pathways

Icariin inhibits oral squamous cell carcinoma cell proliferation and induces apoptosis via inhibiting the NF-κB and PI3K/AKT pathways

Oral squamous cell carcinoma (OSCC), one of the most common types of human cancer, has a high mortality rate and a poor prognosis due to its high rates of recurrence and metastasis. In recent years, icariin (ICA) has been reported to play an important role in a variety of malignancies, such as gastric, colorectal, pancreatic and ovarian cancer. However, its role and mechanism in OSCC remains to be elucidated. The present study aimed to investigate the effect of ICA in OSCC cells and to reveal its underlying mechanisms. The OSCC cell lines SCC9 and Cal 27 were used to explore the effect of different concentrations of ICA on the biological behavior of OSCC cells. The effect of ICA on OSCC cell proliferation and apoptosis was determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide and flow cytometric assays, respectively. Subsequently, the protein expression levels of caspase-3 and cleaved-caspase-3 were detected using western blot analysis. Additionally, the protein and mRNA expression levels of nuclear factor-κB (NF-κB) and phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT) signaling pathway-related factors were determined using western blot analysis and reverse transcription-quantitative PCR, respectively. The results demonstrated that ICA inhibited OSCC cell proliferation and significantly increased the apoptosis rate in a dose-dependent manner. In addition, treatment of OSCC cells with ICA upregulated the protein expression of cleaved-caspase-3 and increased the cleaved-caspase-3/caspase-3 ratio. The protein expression levels of phosphorylated (p)-p65, p-PI3K and p-AKT were decreased in OSCC cells treated with ICA. The aforementioned findings revealed that ICA could attenuate the proliferation of OSCC cells and induce apoptosis via inhibiting the NF-κB and PI3K/AKT signaling pathways. Therefore, the current study provided a new insight into the clinical treatment of OSCC.

Puerarin Enhances the Anti-Tumor Effect of Cisplatin on Drug-Resistant A549 Cancer in vivo and in vitro Through Activation of the Wnt Signaling Pathway

Objective

The effect of PUE on enhancing the anti-cancerous efficacy of DDP on drug-resistant A549/DDP cancer and the underlying mechanisms were thoroughly investigated.

Materials and Methods

The cytotoxicity of PUE, DDP, and PUE + DDP to A549 cells and A549/DDP cells, respectively, is determined by cell apoptosis experiments. Anti-proliferation effect of PUE, DDP, and PUE + DDP on A549 cells and A549/DDP cells is evaluated by the cell cloning assay. Qualitative and quantitative analysis of the levels of PUE, DDP, and PUE + DDP of cell proliferation-related genes and proteins expressions in A549/DDP cells are determined by Western blot assay. The levels of VEGF in A549/DDP cells after different treatment strategies are determined by ELISA assay. Qualitative and quantitative determination of VEGF expression in tumor tissues are done by immunohistochemical staining.

Results

In vitro cellular experiments revealed that co-incubation of A549/DDP cells with PUE and DDP led to a dramatically decreased cell viability and cell survival rate compared with the cells only treated by DDP. Such a stimulating effect of PUE on DDP was further confirmed in vivo with results shown that the A549/DDP cancer-bearing mice treaded by combination therapy achieved the lowest tumor growth rate and longest survival time.

Conclusion

Taking these results together, we can draw the conclusion that the PUE enhances the anti-tumor effect of DDP on the drug-resistant A549 cancer in vivo and in vitro through activation of the Wnt signaling pathway.

RFC3 induces epithelial‑mesenchymal transition in lung adenocarcinoma cells through the Wnt/β‑catenin pathway and possesses prognostic value in lung adenocarcinoma

Lung cancer is a malignant tumor responsible for the highest mortality rate in humans. The identification of novel functional genes is of great importance in the treatment of lung cancer. The reported roles of replication factor C subunit 3 (RFC3) in tumorigenesis are contradictory. The present study aimed to explore the role and mechanism of RFC3 in lung cancer cells. An immunohistochemical study of 165 lung cancer and adjacent tissues was conducted (123 lung adenocarcinoma tissues and 42 lung squamous cell carcinoma tissues). Kaplan-Meier analysis and Cox multivariate analysis were employed to explore the relationship between RFC3 and patient prognosis. In addition, the proliferation, cell cycle distribution and apoptosis of A549 and H1299 cells were determined by MTT assay and flow cytometry, respectively, following cell transfection to induce overexpression and knockdown of RFC3. A Boyden chamber assay and wound-healing assay were conducted to determine the invasive and migratory abilities of A549 and H1299 cells. Western blotting was used to analyze the effects of RFC3 overexpression and RFC3 small interfering RNA-induced knockdown, and to explore the potential mechanism and pathway underlying the effects of RFC3. Positive expression of RFC3 was detected in lung adenocarcinoma, and overexpression of RFC3 shortened the survival time of patients with lung adenocarcinoma. Furthermore, overexpression of RFC3 increased the invasion and migration of A549 cells, whereas knockdown of RFC3 significantly reduced the invasion and migration of H1299 cells. Ectopic expression of RFC3 induced epithelial-mesenchymal transition (EMT), as determined by downregulation of E-cadherin, and upregulation of N-cadherin, vimentin and Wnt signaling target genes, including c-MYC, Wnt1 and β-catenin, and the ratio of phosphorylated-glycogen synthase kinase 3 (GSK3)-β (Ser9)/GSK3-β. In conclusion, RFC3 may be considered a coactivator that promotes the Wnt/β-catenin signaling pathway, and induces EMT and metastasis in lung adenocarcinoma.

Reciprocal regulatory mechanism between miR-214-3p and FGFR1 in FGFR1-amplified lung cancer

MicroRNA (miRNA) and fibroblast growth factor receptor 1 (FGFR1) dysregulation are considered to play an important role in tumor proliferation, invasion, and metastasis. However, the regulatory mechanism between miRNAs and FGFR1 in lung cancer remains unclear and extremely critical. miR-214-3p was sharply decreased and showed a significantly negative correlation with FGFR1 in lung cancer patients (n = 30). Luciferase reporter assay confirmed that miR-214-3p could downregulate FGFR1 by directly targeting 3′-untranslated region (UTR). miR-214-3p inhibited the processes of epithelial–mesenchymal transition and Wnt/MAPK/AKT (Wnt/mitogen-activated protein kinase/AKT) signaling pathway by targeting FGFR1. Moreover, miR-214-3p not only established a negative feedback regulation loop with FGFR1 through ERK (extracellular signal-regulated kinase) but also developed a synergism with FGFR1 inhibitor AZD4547. In conclusion, our study demonstrated the regulatory mechanism between miR-214-3p and FGFR1 in lung cancer. miR-214-3p acts as a vital target in FGFR1-amplified lung cancer by forming a miR-214-3p-FGFR1-Wnt/MAPK/AKT signaling pathway network. Co-targeting miR-214-3p and FGFR1 could provide greater benefits to patients with FGFR1-amplified lung cancer.

Licochalcone A inhibits cell proliferation, migration, and invasion through regulating the PI3K/AKT signaling pathway in oral squamous cell carcinoma

Background: Oral squamous cell carcinoma (OSCC) is one of the most common cancers, with high metastasis and mortality. Licochalcone A (LCA) is a chalconoid from the root of Glycyrrhiza inflata, which has anti-tumor, anti-inflammatory, anti-angiogenesis effects in many cancers. However, the mechanism that underlies LCA regulating cell proliferation, migration, and invasion in OSCC remains poorly understood.

Methods: LY294002 or insulin-like growth factor 1 (IGF-1) were used to block or stimulate the phosphatidylinositol 3 kinase (PI3K)/protein kinase B (AKT) pathway in OSCC cells. Cell proliferation was investigated by MTT assay and proliferating cell nuclear antigen (PCNA) protein level using Western blot. The expression of metastasis-related protein was detected via Western blot. Cell migration and invasion abilities were evaluated by trans-well assay. A murine xenograft model of OSCC was established to investigate the anti-tumor effect of LCA in vivo.

Results: Treatment of LCA inhibited cell proliferation in SCC4 and CAL-27 cells. Moreover, PI3K/AKT signaling was blocked by LY294002, and activated by IGF-1. LCA could suppress proliferation, migration, and invasion of OSCC cells, which was similar to the treatment of LY294002. In addition, LCA decreased IGF-1-induced OSCC progression. In a murine xenograft model, LCA treatment protected against tumor growth and metastasis in vivo.

Conclusions: LCA might inhibit cell proliferation, migration, and invasion through regulating the PI3K/AKT pathway in OSCC, developing a potential chemotherapeutic agent for OSCC.

MicroRNA-124 regulates TRAF6 expression and functions as an independent prognostic factor in colorectal cancer

An increasing number of studies have confirmed that miR-124 exhibits a suppressive role in glioblastoma, cervical cancer and breast cancer; however, the function of miR-124 in colorectal cancer (CRC) has not been completely elucidated. In the present study, miR-124 expression was confirmed by reverse transcription-quantitative PCR in 80 colorectal tissues and para-cancerous tissues. The influence of altered miR-124 expression was analyzed by statistical approaches including Cox multivariate regression analysis and the Kaplan-Meier method, and the target genes of miR-124 were confirmed by luciferase reporter assays. Immunohistochemical techniques were also performed in order to measure the expression levels of target proteins. miR-124 expression was observed to be decreased in colorectal tissue samples, and this phenomenon was correlated with adverse clinical indicators and poor patient survival time. Luciferase reporter assays indicated that miR-124 directly regulated TNF receptor associated factor 6 (TRAF6) 3′-untranslated region (UTR). Hence, it was proposed that miR-124 dysregulation may negatively influence the expression of TRAF6 and therefore serve as a biomarker of epithelial-mesenchymal transition in CRC tissues. In summary, the present study demonstrated that miR-124 regulates the expression of TRAF6, and may potentially function as an independent prognostic factor and therapeutic target in patients with CRC.

Lysophosphatidic acid induces the migration and invasion of SGC-7901 gastric cancer cells through the LPA2 and Notch signaling pathways

Lysophosphatidic acid (LPA), a simple water‑soluble glycerophospholipid with growth factor‑like activity, regulates certain behaviors of multiple cancer types by binding to its receptor, LPA receptor 2 (LPA2). Notch1 is a key mediator in multiple human cancer cell types. The association between LPA2 and Notch1 in gastric cancer cells is not well known. The present study aimed to investigate the function of LPA2 and Notch1 in controlling the migration and invasion activities of SGC‑7901 gastric cancer cells following stimulation with LPA. It was revealed that LPA may stimulate the expression of Notch1 and Hes family bHLH transcription factor 1, and the phosphorylation of protein kinase B which belongs to the Notch pathway. Furthermore, by performing transwell migration and invasion assays, immunofluorescent staining, analyzing the expression of markers for the epithelial‑mesenchymal transition (EMT) and downregulating LPA2 and Notch1 expression, it was verified that LPA2 and Notch1 mediated the metastasis, invasion, EMT and rebuilding of the cytoskeleton of SGC‑7901 cells upon LPA treatment. An immunoprecipitation assay revealed that LPA2 interacted with Notch1 in SGC‑7901 cells. The present study may provide novel ideas and an experimental basis for identifying the factors that affect the functions of SGC‑7901 cells.