Myocardial extracellular volume derived from contrast-enhanced chest computed tomography in longitudinal evaluation of cardiac toxicity in patients treated with immune checkpoint inhibitors.

Background: The immune-related adverse effects after immune checkpoint inhibitors (ICIs) treatment have always been a hot topic. Although the incidence of myocarditis is not high among the related adverse effects, the mortality rate is extremely high once it occurs. In the past, the risk of cancer therapy-related cardiac dysfunction (CTRCD) after drug treatment was evaluated based on imaging examinations, but this evaluation still had certain limitations. Currently, the extracellular volume (ECV) score measurement calculated using cardiac magnetic resonance T1 mapping has become a reliable method for evaluating myocardial toxicity and computed tomography (CT) examination may become an alternative. This study aimed to longitudinally evaluate the cardiac toxicity of patients treated with ICIs using myocardial ECV derived from contrast-enhanced chest CT. Methods: A total of 500 patients with III-IV lung cancer and esophageal cancer treated with ICIs were evaluated. Participants underwent baseline examination and at least 1 follow-up examination after treatment. Contrast-enhanced chest CT-ECV, left ventricular ejection fraction (LVEF), and measurement of cardiac troponin T (cTnT) were conducted before the first treatment, 3-6 months after the first treatment, and about 12 months after the first treatment, respectively. The ECV value of the middle part of the left ventricular septum was evaluated on CT venography and plain scan, the LVEF value was evaluated by color Doppler ultrasound, and the quantity of cTnT was detected by chemiluminescence. Cancer therapy-related cardiac dysfunction was recorded. Results: The mean baseline LVEF value was 68.51%±4.81% (N0=500), and those of LVEF1, LVEF2, and LVEF3 were 68.77%±4.30%, 68.16%±3.59%, and 66.23%±4.20%, respectively (N1=500, N2=467, and N3=361, respectively). There was no significant difference between LVEF1, LVEF2, and LVEF0 (P1=0.095, P2=0.062), whereas LVEF3 was significantly lower than LVEF0 (P<0.001). The average baseline cTnT0 value was 7.42±3.95 (N0=500). The values of cTnT1, cTnT2, and cTnT3 were 10.05±11.40, 12.24±13.59, and 14.54±14.49, respectively (N1=500, N2=467, N3=361). The values of cTnT1, cTnT2, and cTnT3 were significantly higher than cTnT0 (P1<0.001, P2<0.001, P3<0.001). The average ECV0 was 47.14%±7.48% (N0=500). ECV1, ECV2, and ECV3 were 50.85%±6.79%, 53.44%±6.96% and 52.64%±7.58% respectively (N1=500, N2=467 and N3=361). ECV1, ECV2, and ECV3 were significantly higher than ECV0 (P1<0.001, P2<0.001, P3<0.001). CTRCD occurred in 49 patients. There were significant differences between the CTRCD (+) group and the CTRCD (-) group in cTnT1, cTnT2, and cTnT3 (P1<0.001, P2<0.001, and P3<0.001, respectively) and in ECV1, ECV2, and ECV3 (P1=0.039, P2=0.041, and P3=0.013, respectively). Conclusions: CT-ECV began to increase at the early stage after the treatment of ICIs. CT-ECV is a potential biomarker for dynamically monitoring the cardiac toxicity of tumor patients after receiving ICIs. ECV may be used to speculate the CTRCD caused by the treatment of ICIs.

Primary Pulmonary Lymphoepithelioma-like Carcinoma: A Case Report Utilizing Camrelizumab and Anlotinib for Prolonged Survival.

BACKGROUND: Primary Pulmonary Lymphoepithelioma-like Carcinoma (PPLELC) is a rare form of cancer for which no standard treatment has been established to date. Patients with advanced-stage PPLELC generally have a poor prognosis with overall survival of 22.7 months. CASE PRESENTATION: Here, we report a case of advanced primary pulmonary lymphoepithelioma-like carcinoma. Initially, the patient underwent a first-line (GP) and a second-line (DP) of chemotherapy, which provided temporary relief but resulted in varying degrees of myelosuppression. When the disease progressed again, we administered a third-line treatment consisting of camrelizumab combined with anlotinib. RESULT: This resulted in a progression-free survival of over 26 months without significant toxic side effects. CONCLUSION: Our findings suggest that combining camrelizumab and anlotinib could lead to a long progressionfree survival in patients with advanced PPLELC.

Efficacy and safety of thrombopoietin receptor agonists in solid tumors with chemotherapy-induced thrombocytopenia: a meta-analysis.

OBJECTIVE: To evaluate the efficacy and safety of thrombopoietin receptor agonists (TPO-RAs) in solid tumors with chemotherapy-induced thrombocytopenia (CIT). METHODS: We conducted a comprehensive search of PubMed, FMRS, Cochrane Library, Web of Science, EMBASE, and ClinicalTrials.gov for randomized controlled trials (RCTs) reporting the efficacy and safety of TPO-RAs in solid tumors with CIT. The search was limited to articles published before April 30, 2022. Primary outcomes included chemotherapy dose reduction or delays, platelet transfusion, the incidence of grade 3 or 4 thrombocytopenia, and bleeding events. Secondary outcomes encompassed the incidence of platelet count > 400 × 109/L, adverse events (AEs), serious AEs, thrombosis, and mortality. RESULTS: Our analysis encompassed six studies: five rigorous RCTs and one unique study comparing romiplostim to an observation group, involving a total of 489 patients. For primary outcomes, TPO-RAs significantly reduced the incidence of grade 3 or 4 thrombocytopenia (RR = 0.69, 95% CI: 0.52-0.91). After applying the Bonferroni correction for multiple comparisons, the significance of the reduction in grade 3 or 4 thrombocytopenia incidence persisted (P = 0.008). TPO-RAs showed no significant impact on chemotherapy dose reduction or delays (RR = 0.81, 95% CI: 0.65-1.01), platelet transfusion (RR = 1.04, 95% CI: 0.48-2.27), or bleeding events (RR = 0.50, 95% CI: 0.23-1.10). In terms of safety, there were no significant difference in the incidence of any AEs (RR = 0.98, 95% CI:0.92-1.04), serious AEs (RR = 0.79, 95% CI:0.45-1.40), thrombotic events (RR = 1.20, 95% CI:0.51-2.84) and mortality (RR = 1.15, 95% CI:0.55-2.41). CONCLUSIONS: This meta-analysis suggests that TPO-RAs are generally well-tolerated. However, their efficacy in solid tumors with CIT appears limited, as they only demonstrate a reduction in the incidence of grade 3 or 4 thrombocytopenia.

Fruquintinib in combination with sintilimab or TAS-102 as third-line or above treatment in patients with metastatic colorectal cancer: a real-world study.

Background: For metastatic colorectal cancer (mCRC), the efficacy of third-line or above treatments is not ideal. Combining targeted vascular endothelial growth factor (VEGF) or vascular endothelial growth factor receptor (VEGFR) biological agents with chemotherapy or anti-programmed death receptor 1 (PD-1) treatment can bring longer survival benefits to patients with mCRC compared with the application of a single drug. In this study, fruquintinib was used as the research drug, and the main purpose was to compare the efficacy and safety of fruquintinib in combination with sintilimab (FS) or trifluridine and tipiracil (TAS-102) (FT) in the third-line or above treatment in mCRC patients. Methods: Based on real-world clinical practice, mCRC patients who progressed after second-line or higher-line chemotherapy regimens and received FS or FT as third-line or above treatment from December 2020 to November 2022 were analyzed. Progression-free survival (PFS) was the primary endpoint. Safety, disease control rate (DCR) and objective response rate (ORR) were secondary end points. Results: In the FS group, 47 patients received FS, and in the FT group, 45 patients received FT. The DCR values in the FS and FT groups were 80.9% (38/47) and 55.6% (25/45), respectively (P<0.05). The median PFS (mPFS) in the FS group was 6.0 months, and the mPFS in the FT group was 3.5 months (P<0.05). Most adverse events (AEs) were grade 1-2 in severity. Conclusions: As a third-line or above regimen in mCRC patients, compared to FT, treatment with FS provides a higher DCR and longer mPFS and is better tolerated. The combination of fruquintinib and sintilimab may become a new treatment option for mCRC patients.

S-1 maintenance therapy in advanced gastric cancer without disease progression after first-line chemotherapy: A retrospective analysis.

For patients with advanced gastric cancer after chemotherapy, the optimal mode of maintenance therapy is not yet clear. This research aimed to compare the efficacy and adverse effects of S-1 maintenance therapy and follow-up observation in patients with advanced gastric cancer without disease progression after first-line combined chemotherapy. This study retrospectively analyzed 106 patients from January 2018 to December 2021. The primary endpoints were overall survival and progression-free survival, the secondary endpoint was chemotherapy-related toxicity, and the curative effects and baseline characteristics of the patients were analyzed. Longer progression-free survival and overall survival were observed in the S-1 maintenance treatment group than in the follow-up observation group (p < 0.001). No obvious differences existed in the subgroup results regarding progression-free survival or overall survival (p > 0.05). In the maintenance treatment group, the occurrence of thrombocytopenia and hand-foot syndrome was significantly increased (p < 0.001). No toxicity-related deaths occurred. The included patients without disease progression after first-line combined chemotherapy can achieve significant survival benefits by receiving S-1 maintenance therapy. The patient's tolerance to S-1 maintenance therapy was good.

Characteristics and Predictors of Venous Thromboembolism Among Lymphoma Patients Undergoing Chemotherapy: A Cohort Study in China.

Background: Venous thromboembolism (VTE) is a potential complication among lymphoma patients. We evaluated the incidence rate and predictors of VTE in lymphoma patients undergoing chemotherapy. Methods: The present study retrospectively studied 1,069 patients with lymphoma who were treated with chemotherapy from 2018 to 2020. We investigated clinical predictors of VTE among all patients. The follow-up results were obtained via telephone communication and from inpatient and outpatient records. Results: A total of 1,069 patients underwent chemotherapy for lymphoma. During a mean follow-up of 23.1 months, 52 (4.9%) patients developed VTE. According to a multivariate analysis, the five variables found to be independently associated with VTE were male sex (HR 2.273, 95% CI 1.197-4.316, p = 0.012), age >64-years-old (HR 2.256, 95% CI 1.017-5.005, p = 0.045), the number of cycles of chemotherapy (HR 4.579, 95% CI 1.173-17.883, p = 0.029), platelet count ≥350 × 109/L (HR 2.533, 95% CI 1.187-5.406, p = 0.016), and D-dimer >0.5 mg/L (HR 4.367, 95% CI 2.124-8.981, p < 0.001). Conclusion: This population-based study confirms the risk factors for VTE among patients with lymphoma who underwent chemotherapy and confirms that targeted thromboprophylaxis may reduce the burden of VTE in this population.

Role of Kruppel-like factor 4 in regulating inhibitor of apoptosis-stimulating protein of p53 in the progression of gastric cancer.

Gastric cancer (GC) remains one of the leading causes of cancer-associated mortality. The overexpression of inhibitor of apoptosis-stimulating protein of p53 (iASPP) has been detected in GC tissues but the function of iASPP in the viability of GC cells and its underlying molecular mechanism remains unknown. Kruppel-like factor 4 (KLF4) is a tumor suppressor gene in GC and it may interact with p53. iASPP is an evolutionarily conserved inhibitor of p53, whereas KLF4 may be negatively associated with iASPP in GC. However, whether KLF4 has regulatory effects on iASPP remains to be investigated. The objective of the present study was to examine the function of iASPP and KLF4 in the proliferation of GC cells and to determine whether KLF4 has regulatory effects on iASPP. It was demonstrated that iASPP was upregulated and KLF4 was downregulated in GC cell lines. Downregulation of iASPP inhibited the proliferation and colony formation ability, and promoted the apoptosis of GC cells. Additionally, upregulation of KLF4 inhibited the proliferation and colony formation ability, and promoted apoptosis of GC cells. Furthermore, upregulation of KLF4 inhibited the expression of iASPP. Upregulation of iASPP following overexpression of KLF4 reversed the KLF4-mediated effects in GC cells. In vivo upregulation of KLF4 or downregulation of iASPP inhibited the growth of tumors, whereas upregulation of iASPP promoted the growth of tumors. In conclusion, iASPP may act as an oncogene that promotes the proliferation of GC cells. The results demonstrated that KLF4 was a negative regulatory factor of iASPP and that overexpression of iASPP inhibited the effects of KLF4. Thus, downregulation of KLF4 in GC may lead to overexpression of iASPP and promote the development of cancer.

The effect of icotinib combined with chemotherapy in untreated non-small-cell lung cancer that harbored EGFR-sensitive mutations in a real-life setting: a retrospective analysis.

PURPOSE: This study was conducted to compare the efficacy of a combination of icotinib and chemotherapy with icotinib or chemotherapy alone in untreated non-small cell lung cancer (NSCLC) patients harboring epidermal growth factor receptor (EGFR)-sensitive mutations and to analyze the curative effect of different treatments on different genetic mutations (EGFR 19 exon deletion and L858R mutation) in a real-life setting. PATIENTS AND METHODS: One hundred ninety-one patients were studied in this retrospective analysis from January 2013 to December 2015. The baseline characteristics, curative effects and adverse events of patients were analyzed. The primary endpoint was progression free survival (PFS). RESULTS: Longer PFS and overall survival (OS), and better objective response rate (ORR) were observed in the combination group compared to icotinib or chemotherapy along. For patients with an EGFR 19 exon deletion, the PFS, OS, and ORR in the combination group were superior to those in the icotinib or chemotherapy group. For the patients with the EGFR L858R mutation, better PFS and ORR were observed in the combination group, but OS was not obviously prolonged. Grade 3 or 4 adverse events were most commonly reported with combination therapy or chemotherapy alone. No possible drug-related interstitial lung disease or of drug related deaths occurred. CONCLUSION: The combination of icotinib and chemotherapy in patients with untreated NSCLC harboring sensitive EGFR mutations resulted in improved PFS and OS, especially in those who harbored the EGFR exon 19 deletion.

Inhibition of Hes1 enhances lapatinib sensitivity in gastric cancer sphere-forming cells.

It has been considered that the neurogenic locus notch homolog protein (Notch) signaling pathway serves an essential role in cellular differentiation, proliferation and apoptosis. However, the function of the Notch signaling pathway in gastric cancer stem cells (GCSCs) and epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) sensitivity remains unclear. The present study aimed to delineate the role of the Notch1 signaling pathway in GCSCs and lapatinib sensitivity. Sphere-forming cells were separated from human gastric cancer MKN45 parental cells. The sphere-forming cells exhibited characteristics of CSCs and higher Notch1 expression compared with that of parental cells. To investigate the role of the Notch1 signaling pathway in GCSCs, the expression of transcription factor Hes1 (Hes1) was knocked down using small interfering RNA against Hes1. It was observed that Hes1 expression was significantly downregulated in knocked down cells. The inhibition of Hes1 suppressed the properties of CSCs, as indicated by significant decreases in the expression of the transcription factor sex determining region Y-box 2, epithelial cell adhesion molecule and the homeobox protein Nanog and reduced spheroid colony formation. In addition, epithelial-mesenchymal transition was significantly impaired in sphere-forming cells following Hes1 knockdown. Furthermore, the inhibition of Hes1 effectively enhanced lapatinib sensitivity in sphere-forming cells. These results suggest that sphere-forming gastric cancer cells possess the characteristics of CSCs, and that the Notch1 signaling pathway serves an essential role in the maintenance of CSCs and lapatinib sensitivity.

Silencing of ATM expression by siRNA technique contributes to glioma stem cell radiosensitivity in vitro and in vivo.

Evidence has shown that both high expression of the ataxia-telangiectasia mutated (ATM) gene and glioma stem cells (GSCs) are responsible for radioresistance in glioma. Thus, we hypothesized that brain tumor radiosensitivity may be enhanced via silencing of the ATM gene in GSCs. In the present study we successfully induced GSCs from two cell lines and used CD133 and nestin to identify GSCs. A lentivirus was used to deliver siRNA-ATMPuro (A group) to GSCs prior to radiation, while siRNA-HKPuro (N group) and GSCs (C group) were used as negative and blank controls, respectively. RT-qPCR and western blotting were performed to verify the efficiency of the siRNA-ATM technique. The expression of the ATM gene and ATM protein were significantly downregulated post-transfection. Cell Counting Kit-8 (CCK-8) and colony formation assays revealed that the A group demonstrated weak cell proliferation and lower survival fractions post-irradiation compared to the C/N groups. Flow cytometry was used to examine the percentage of cell apoptosis and G2 phase arrest, which were both higher in the A group than in the C/N groups. We found that the comet tail percentage evaluated by comet assay was higher in the A group than in the C/N groups. After radiation treatment, three radiosensitive genes [p53, proliferating cell nuclear antigen (PCNA), survivin] exhibited a decreasing tendency as determined by RT-qPCR. Mice underwent subcutaneous implantation, followed by radiation, and the resulting necrosis and hemorrhage were more obvious in the A group than in the N groups. In conclusion, silencing of ATM via the siRNA technique improved radiosensitivity of GSCs both in vitro and in vivo.

A regulatory loop involving miR-29c and Sp1 elevates the TGF-ß1 mediated epithelial-to-mesenchymal transition in lung cancer.

Specificity protein1 (Sp1) is required for TGF-ß-induced epithelial-to-mesenchymal transition (EMT) which has been demonstrated to aggravate the progression of cancer including lung cancer. microRNA-29c (miR-29c) is identified to inhibit EMT, but the correlation between miR-29c and Sp1 in human lung cancer remain incompletely clarified. Here, we confirmed decreased expression of miR-29c and enhanced expression of Sp1 in lung cancer tissues (n = 20) and found that Sp1 could be targeted and inhibited by miR-29c. Besides, the expression of miR-29c was down-regulated in high-metastatic lung cancer cell lines and TGF-ß1-treated cells. The inhibition of miR-29c or overexpression of Sp1 in 95C and A549 cells dramatically enhanced the cell migration and invasion, and also induced the decrease in the expression of epithelial markers, e.g. thyroid transcription factor 1 (TTF-1) and E-cadherin, together with an increase in mesenchymal markers including vimentin, α-smooth muscle actin (α-SMA), which could be restored by overexpression of miR-29c mimics during the TGF-ß-induced EMT. Moreover, dual-luciferase reporter assay was performed and the results indicated that miR-29c/Sp1 could form an auto-regulatory loop with TGF-ß1, which impaired TGFB1 transcription. Furthermore, miR-29c overexpression could abrogate the tumor progression and inhibit the Sp1/TGF-ß expressions in vivo, indicating that miR-29c could be a tumor suppressor and repress the Sp1/TGF-ß axis-induced EMT in lung cancer.

Silencing of ataxia-telangiectasia mutated by siRNA enhances the in vitro and in vivo radiosensitivity of glioma.

It is reported that high expression of the ataxia-telangiectasia mutated (ATM) gene is linked with radioresistance in glioma. We hypothesized that the radiosensitivity of this brain tumor is enhanced by silencing of the ATM gene. We transfected the glioma cell line U251 with the siRNA-ATMpuro (group A) lentivirus or the siRNA-HKpuro (group N, negative control) lentivirus before irradiation. RT-qPCR and western blotting were performed to verify the efficiency of siRNA­mediated ATM silencing. Expression levels of the ATM gene and protein were obviously downregulated after transfection. Moreover, the expression of the p53, PCNA and survivin genes, which are related to radiosensitivity, was also decreased. CCK-8 and colony formation assays showed lower cell proliferation and survival in group A than in groups N and C (control group that was not transfected with any siRNA). The level of double-stranded DNA breaks was also greater in group A, as determined by the comet tail assay. Flow cytometry showed a higher rate of cell apoptosis and a higher number of cells in the G2 phase in group A. Furthermore, caspase-3, caspase-8 and caspase-9 activity was also higher in group A. In vivo analysis in mouse models created by implantation of the transfected cell lines showed that the amount of necrosis and hemorrhage was higher in group A than that in the control groups. In conclusion, silencing of ATM via the siRNA technique could improve the in vitro and in vivo radiosensitivity of glioma cells.

Downregulation of inhibitor of apoptosis­stimulating protein of p53 inhibits proliferation and promotes apoptosis of gastric cancer cells.

Gastric cancer (GC) remains one of the leading causes of cancer-associated mortality. Inhibitor of apoptosis-stimulating protein of p53 (iASPP) is a member of the inhibitory apoptosis-stimulating protein p53 family. The overexpression of iASPP has been detected in several types of tumor in humans. However, the role of iASPP in GC remains to be elucidated. The objectives of the present study were to detect the expression of iASPP in GC and examine the potential role of iASPP in GC cell lines. Using reverse transcription-quantitative polymerase chain reaction and western blot analyses, it was identified that the expression of iASPP in GC tissues and GC cell lines was higher compared with that in adjacent normal tissues and in a normal gastric mucosa cell line (GES-1). To examine the role of iASPP in GC cells, the expression of iASPP was inhibited using a small interfering (si)RNA against iASPP and it was observed that iASPP expression was significantly downregulated. Using MTT assays, colony-formation assays and flow cytometry, it was identified that the inhibition of iASPP was able to significantly inhibit the proliferation and colony forming ability and promote apoptosis in GC cells. To examine the role of iASPP in GC cells in vivo, GC cells, which were infected with iASPP-siRNA or control-siRNA were subcutaneously injected into nude mice. It was identified that downregulation of iASPP significantly inhibited tumor growth in vivo. Thus, iASPP may be a potential molecular target in GC therapy.

Gastric tumor-initiating CD44+ cells and epithelial-mesenchymal transition are inhibited by γ-secretase inhibitor DAPT.

It has been proposed that the Notch signaling pathway may serve a pivotal role in cellular differentiation, proliferation and apoptosis. However, the function of Notch signaling in gastric cancer stem cells (GCSCs) is largely unknown. The present study aimed to delineate the role of the Notch1 pathway in GCSCs and during epithelial-mesenchymal transition (EMT). Flow cytometry was used to isolate CD44+ cells from the human gastric cancer cell line, MKN45. CD44+ cells displayed the characteristics of CSCs and exhibited higher Notch1 expression compared with CD44- cells. To investigate the role of the Notch1 pathway in GCSCs, CD44+ cells were treated with the γ-secretase inhibitor DAPT. DAPT treatment inhibited the expression of the Notch1 downstream target Hes1 and EMT markers, suppressed the properties of CSCs and impaired the invasion and proliferation capabilities of CD44+ cells. In addition, intraperitoneal treatment with DAPT effectively inhibited the growth of CD44+ cell xenograft tumors. The present study indicated that CD44+ GCSCs possess the characteristics of CSCs and that the Notch1 pathway serves a critical role in the maintenance of CSCs and EMT.

microRNA-503 inhibits gastric cancer cell growth and epithelial-to-mesenchymal transition.

Epithelial-to-mesenchymal transition (EMT) is believed to be associated with cancer cell malignancy, and also to cause cancer invasion and metastasis. Recent evidence indicates that small non-protein coding RNA [microRNAs (miRNAs/miRs)] may act as powerful regulators of EMT. The present study aimed to systematically delineate miR-503 expression in gastric cancer and analyse the function of miR-503 in gastric cancer EMT. In the present study, miR-503 expression was detected in gastric cancer cell lines and gastric cancer tissues by quantitative polymerase chain reaction. Gastric cancer cell migration, invasion and proliferation capabilities were analysed by Transwell, MTT and clonability assays. The expression of mesenchymal markers, including fibronectin, vimentin, N-cadherin, SNAIL and the epithelial marker, E-cadherin, was examined by immunoblot analysis following miR-503 transfection. miR-503 expression was found to be reduced in gastric cancer cell lines compared with normal gastric mucosa cell lines, and the expression of miR-503 was upregulated in non-metastatic-derived gastric cancer cell lines compared with metastatic-derived lines. miR-503 expression levels were significantly reduced in tumour tissues in comparison with adjacent normal mucosa tissues, and the miR-503 expression levels in patients with metastases were significantly lower than those in patients without. miR-503 inhibited gastric cancer cell migration, invasion and proliferation. Fibronectin, vimentin, N-cadherin and SNAIL protein levels were decreased, but E-cadherin expression was increased in an AGS cell line transfected with miR-503. Taken together, the present findings indicate that miR-503 acts as a novel tumour suppressor gene in gastric cancer and can inhibit EMT in gastric cancer cells.

Gastric cancer cell growth and epithelial-mesenchymal transition are inhibited by γ-secretase inhibitor DAPT.

The Notch signaling pathway may be important in the development and progression of several malignancies. However, the functions of Notch signaling in epithelial-mesenchymal transition (EMT) remain largely unknown. The aim of the present study was to delineate Notch1 expression in gastric cancer (GC) and its function in GC EMT. Using quantitative polymerase chain reaction and western blot analysis, the expression of Notch1 was found to increase in GC cell lines compared with the normal gastric mucosa cell line. In addition, Notch1 expression was found to be downregulated in the non-metastatic-derived GC cell line compared with the metastatic-derived cell line. Furthermore, Notch1 expression was significantly increased in the tumor tissues compared with the adjacent normal mucosa tissues, as well as in patients with metastases than in patients without metastases. To explore the role of the Notch1 signaling pathway in EMT, the GC cell lines, AGS and MKN45, were treated with γ-secretase inhibitor DAPT. Using MTT, Transwell and clonality assays, DAPT was found to inhibit the expression of the Notch1 downstream target, Hes1, and impair the ability of the GC cell lines to migrate, invade and proliferate. The protein levels of the mesenchymal markers, vimentin, neural cadherin and Snail, were decreased; however, the expression of the epithelial marker, epithelial cadherin, was increased in the GC cell lines treated with DAPT. These results indicated that the Notch1 signaling pathway may be important in the development and progression of GC. In conclusion, DAPT inhibits the Notch1 signaling pathway, as well as the growth, invasion, metastasis and EMT of GC cells.

MicroRNA-338 inhibits growth, invasion and metastasis of gastric cancer by targeting NRP1 expression.

NRP1 as multifunctional non-tyrosine-kinase receptors play critical roles in tumor progression. MicroRNAs (miRNAs) are an important class of pervasive genes that are involved in a variety of biological functions, particularly cancer. It remains unclear whether miRNAs can regulate the expression of NRP1. The goal of this study was to identify miRNAs that could inhibit the growth, invasion and metastasis of gastric cancer by targeting NRP1 expression. We found that miR-338 expression was reduced in gastric cancer cell lines and in gastric cancer tissues. Moreover, we found that miR-338 inhibited gastric cancer cell migration, invasion, proliferation and promoted apoptosis by targeting NRP1 expression. As an upstream regulator of NRP1, miR-338 directly targets NRP1. The forced expression of miR-338 inhibited the phosphorylation of Erk1/2, P38 MAPK and Akt; however, the expression of phosphorylated Erk1/2, P38 MAPK and Akt was restored by the overexpression of NRP1. In AGS cells infected with miR-338 or transfected with SiNRP1, the protein levels of fibronectin, vimentin, N-cadherin and SNAIL were decreased, but the expression of E-cadherin was increased. The expression of mesenchymal markers in miR-338-expressing cells was restored to normal levels by the restoration of NRP1 expression. In vivo, miR-338 also decreased tumor growth and suppressed D-MVA by targeting NRP1. Therefore, we conclude that miR-338 acts as a novel tumor suppressor gene in gastric cancer. miR-338 can decrease migratory, invasive, proliferative and apoptotic behaviors, as well as gastric cancer EMT, by attenuating the expression of NRP1.