HCRP1 inhibits cell proliferation and invasion and promotes chemosensitivity in esophageal squamous cell carcinoma

Demethylzelasteral inhibits proliferation and EMT via repressing Wnt/β-catenin signaling in esophageal squamous cell carcinoma

As a kind of tumor commonly seen, no effective treatment is available for esophageal squamous cell carcinoma (ESCC). Therefore, seeking a new treatment is urgent. Demethylzeylasteral (T-96) isolated from Tripterygium wilfordii root bark embraces outstanding good antitumor activity. However, as for the mechanism of T-96 work on ESCC cells, it is rarely reported. In this study, we found that T-96 has inhibition when ESCC cells are proliferating, migrating and cloning. Moreover, relevant effects are influenced by dose and time. And T-96 can result in the stop of G2/M phase and induce apoptosis of ESCC cells. In addition, the expressions of Cyclin B1, Cyclin D1, Bcl-2, PARP1 and Survivin were decreased after starch demethylation. Despite of this, Bax and PARP1's expressions went up. To add up, there was an obvious increase in the expression of E-cadherin, while that of N-cadherin, Vimentin and MMP9 decreased after T-96 treatment. Moreover, the expression of Wnt/β-Catenin pathway, which concerns proteins β-Catenin, c-Myc and Wnt3a decreased. Our study shows that T-96 inhibits the proliferation and migration of esophageal cancer cells through Wnt/β-catenin pathway. Moreover, it gives rise to cell cycle arrest and apoptosis. According to the research results, T-96 tends to be put into use when treating ESCC patients, thus laying the experimental foundation for clinical research.

Concurrent depletion of Vps37 proteins evokes ESCRT-I destabilization and profound cellular stress responses

Molecular details of how endocytosis contributes to oncogenesis remain elusive. Our in silico analysis of colorectal cancer (CRC) patients revealed stage-dependent alterations in the expression of 112 endocytosis-related genes. Among them, transcription of the endosomal sorting complex required for transport (ESCRT)-I component VPS37B was decreased in the advanced stages of CRC. Expression of other ESCRT-I core subunits remained unchanged in the investigated dataset. We analyzed an independent cohort of CRC patients, which also showed reduced VPS37A mRNA and protein abundance. Transcriptomic profiling of CRC cells revealed non-redundant functions of Vps37 proteins. Knockdown of VPS37A and VPS37B triggered p21 (CDKN1A)-mediated inhibition of cell proliferation and sterile inflammatory response driven by the nuclear factor (NF)-κB transcription factor and associated with mitogen-activated protein kinase signaling. Co-silencing of VPS37C further potentiated activation of these independently induced processes. The type and magnitude of transcriptional alterations correlated with the differential ESCRT-I stability upon individual and concurrent Vps37 depletion. Our study provides novel insights into cancer cell biology by describing cellular stress responses that are associated with ESCRT-I destabilization.

Inhibited MicroRNA-301 Restrains Angiogenesis and Cell Growth in Esophageal Squamous Cell Carcinoma by Elevating PTEN

OBJECTIVE

Esophageal squamous cell carcinoma (ESCC) is featured by early metastasis and late diagnosis. MicroRNA-301 (miR-301) is known to participate in diverse cancers. Nevertheless, effects of miR-301 on ESCC remain unexplored. Thus, we aim to explore the role of miR-301 in ESCC progression.

METHODS

Expression of miR-301 and phosphatase and tensin homologue (PTEN) in ESCC tissues and cell lines was assessed. Next, the screened cells were treated with altered miR-301 or PTEN oligonucleotide and plasmid, and then, the colony formation ability, cell viability, migration, invasion, cell cycle distribution and apoptosis of ESCC cells were assessed. Moreover, tumor growth and microvessel density (MVD) were also assessed, and the targeting relationship between miR-301 and PTEN was affirmed.

RESULTS

MiR-301 was upregulated, and PTEN was downregulated in ESCC tissues and cells. KYSE30 cells and Eca109 cells were selected for functional assays. In KYSE30 cells, inhibited miR-301 or overexpressed PTEN suppressed cell malignant behaviors, and silenced PTEN eliminated the impact of miR-301 inhibition on ESCC progression. In Eca109 cells, miR-301 overexpression or PTEN inhibition promoted cell malignant behaviors, and PTEN overexpression reversed the effects of miR-301 elevation on ESCC progression. The in vivo assay revealed that miR-301 inhibition or PTEN overexpression repressed ESCC tumor growth and MVD, and miR-301 elevation or PTEN reduction had contrary effects. Moreover, PTEN was targeted by miR-301.

CONCLUSION

Taken together, results in our study revealed that miR-301 affected cell growth, metastasis and angiogenesis via regulating PTEN expression in ESCC.

Autophagy-dependent cell cycle arrest in esophageal cancer cells exposed to dihydroartemisinin

Background

Dihydroartemisinin (DHA), a derivate of artemisinin, is an effective antimalarial agent. DHA has been shown to exert anticancer activities to numerous cancer cells in the past few years, while the exact molecular mechanisms remain to be elucidated, especially in esophageal cancer.

Methods

Crystal violet assay was conducted to determine the cell viability of human esophageal cancer cell line Eca109 treated with DHA. Tumor-bearing nude mice were employed to evaluate the anticancer effect of DHA in vivo. Soft agar and crystal violet assays were used to measure the tumorigenicity of Eca109 cells. Flow cytometry was performed to evaluate ROS or cell cycle distribution. GFP-LC3 plasmids were delivered into Eca109 cells to visualize autophagy induced by DHA under a fluorescence microscope. The mRNA and protein levels of each gene were tested by qRT-PCR and western blot, respectively.

Results

Our results proved that DHA significantly reduced the viability of Eca109 cells in a dose- and time-dependent manner. Further investigation showed that DHA evidently induced cell cycle arrest at the G2/M phase in Eca109 cells. Mechanistically, DHA induced intracellular ROS generation and autophagy in Eca109 cells, while blocking ROS by an antioxidant NAC obviously inhibited autophagy. Furthermore, we found that telomere shelterin component TRF2 was down-regulated in Eca109 cells exposed to DHA through autophagy-dependent degradation, which could be rescued after autophagy was blocked by ROS inhibition. Moreover, the DNA damage response (DDR) was induced obviously in DHA treated cells. To further explore whether ROS or autophagy played a vital role in DHA induced cell cycle arrest, the cell cycle distribution of Eca109 cells was evaluated after ROS or autophagy blocking, and the results showed that autophagy, but not ROS, was essential for cell cycle arrest in DHA treated cells.

Conclusion

Taken together, DHA showed anticancer effect on esophageal cancer cells through autophagy-dependent cell cycle arrest at the G2/M phase, which unveiled a novel mechanism of DHA as a chemotherapeutic agent, and the degradation of TRF2 followed by DDR might be responsible for this cell phenotype.

LTBP1 promotes esophageal squamous cell carcinoma progression through epithelial-mesenchymal transition and cancer-associated fibroblasts transformation

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is one of the most prevalent cancers worldwide. Due to its high morbidity and mortality rates, it is urgent to find a molecular target that contributes to esophageal carcinogenesis and progression. In this research, we aimed to investigate the functions of Latent transforming growth factor β binding protein 1(LTBP1) in ESCC progression and elucidate the underlying mechanisms.

METHODS

The tandem mass tag-based quantitative proteomic approach was applied to screen the differentially expressed proteins (DEPs) between 3 cases of ESCC tumor samples and paired normal tissues. Then the DEPs were validated in human ESCC tissues using western blot assays and GEPIA database respectively. The expression level of LTBP1 was detected in 152 cases of ESCC tissues and paired normal tissues. Loss-of-function assays were performed to detect the function of LTBP1 in vivo and in vitro. Immunofluorescence and Western blot assays were used to detect the expression of apoptosis, epithelial-mesenchymal transition (EMT) and cancer-associated fibroblasts (CAFs) markers.

RESULTS

A total of 39 proteins were screened to be up-regulated (ratio > 2.0) in all three ESCC tissues. The results of immunohistochemistry assays indicated that the expression level of LTBP1 was higher in ESCC tissues than that in paired normal tissues (p < 0.001). Overexpression of LTBP1 was positively associated with lymphatic metastasis in ESCC (p = 0.002). Down-regulation of LTBP1 inhibited the invasion and migration as well as metastatic abilities in vitro and in vivo. It was also observed the down-regulation of LTBP1 not only decreased the mesenchymal phenotypes but also inhibited TGFβ-induced EMT in ESCC cells. We further found that down-regulation of LTBP1 enhanced ESCC cells' sensitivity to 5-FU treatment. Inhibition of LTBP1 expression could also attenuate induction of CAFs transformation and restrain fibroblast express fibronectin (FN1) in ESCC cells.

CONCLUSION

Overexpression of LTBP1 was associated with lymph node metastasis in ESCC. Our results indicated that LTBP1 not only increased the malignant behaviors of ESCC cells but also induced EMT and CAFs transformation. Our studies suggested an oncogenic role of LTBP1 in ESCC progression and it may serve as a potential therapeutic target for ESCC patients.

Silencing of Peroxiredoxin 1 Inhibits the Proliferation of Esophageal Cancer Cells and Promotes Apoptosis by Inhibiting the Activity of the PI3K/AKT Pathway

Objective

To study the effect of peroxiredoxin 1 (PRDX1) on esophageal squamous carcinoma cells and determine whether it plays a role in regulating the PI3K/AKT signaling pathway.

Methods

Three esophageal squamous cell carcinoma cell lines (Eca-109, EC9706, and KYSE150) and one normal cell line (human esophageal epithelial cells) were selected. The protein expression of peroxiredoxin 1 (PRDX1) and the activity of the PI3K/AKT pathway were detected via Western blotting. The proliferation ability of cells was detected through the MTT assay and cell clone formation. Apoptosis was detected using flow cytometry. Subsequently, cells were treated with a PI3K/AKT pathway inhibitor and activator, alone or in combination with silencing of PRDX1, and the above indicators were re-tested.

Results

The expression of PRDX1 and activity of PI3K/AKT pathway-associated proteins were higher in esophageal cancer cells than in normal esophageal epithelial cells. Compared with normal human esophageal epithelial cells, the proliferation of the three types of esophageal cancer cells was increased, whereas their level of apoptosis was decreased (p<0.05). In Eca-109 cells (cell line with silenced expression of PRDX1), the expression of PRDX1 was significantly decreased. In contrast to the control group, the proliferation and clonality of cells in the silencing PRDX1 group was decreased, the proportion of apoptotic cells was increased, and the phosphorylation levels of PI3K and AKT were decreased (p<0.05). Compared with the control group, treatment with the inhibitor LY294002 alone significantly inhibited cell proliferation and promoted apoptosis (p<0.05); this effect was similar to that observed in the silencing PRDX1 group.

Conclusion

PRDX1 was highly expressed in esophageal cancer cells. Silencing of PRDX1 can inhibit the proliferation of esophageal cancer cells and promote apoptosis. The mechanism involved in this process may be related to the inhibition of the PI3K/AKT signaling pathway.

Emetine Synergizes with Cisplatin to Enhance Anti-Cancer Efficacy against Lung Cancer Cells

Cisplatin is still the primary therapeutic choice for advanced lung cancers without driver mutations. The occurrence of cisplatin resistance is a major clinical problem in lung cancer treatment. The natural extracted agent emetine reportedly has anticancer effects. This study aimed to explore the possible role of emetine in cisplatin resistance. We used cell viability, Western blot, and Wnt reporter assays to show that emetine suppresses proliferation, β-catenin expression, and Wnt/β-catenin signaling in non-small cell lung cancer (NSCLC). The synergism of emetine and cisplatin was assessed by constructing isobolograms and calculating combination index (CI) values using the Chou-Talalay method. Emetine effectively synergized with cisplatin to suppress the proliferation of cancer cells. Furthermore, nuclear β-catenin and cancer stem cell-related markers were upregulated in the cisplatin-resistant subpopulation of CL1-0 cells. Emetine enhanced the anticancer efficacy of cisplatin and synergized with cisplatin in the cisplatin-resistant subpopulation of CL1-0 cells. Taken together, these data suggest that emetine could suppress the growth of NSCLC cells through the Wnt/β-catenin pathway and contribute to a synergistic effect in combination with cisplatin.