Irinotecan plus raltitrexed as second-line treatment in locally advanced or metastatic colorectal cancer patients: a prospective open-label, single-arm, multi-center, phase II study.

BACKGROUND: Colorectal cancer is the third most common cancer and the second leading cause of cancer death. There are limited therapeutic options for the treatment of locally advanced or metastatic colorectal cancers which fail first-line chemotherapy. Phase I/II studies showed that the combined application of the raltitrexed and irinotecan has significant synergistic effect and acceptable toxicity. However, most of these previous studies have relatively small sample size. METHODS: This is a prospective open-label, single-arm, multi-center, Phase II trial. Brief inclusion criteria: patients were aged 18 to 75 years with locally advanced or metastatic colorectal cancer after failure of 5-FU and oxaliplatin therapy. Enrolled patients received raltitrexed (3 mg/m2, d1) and irinotecan (180 mg/m2, d1) each 21-day cycle until disease progression or unacceptable toxicity. The primary endpoint was progression-free survival, and the secondary endpoints were disease control rate, objective response rate, overall survival and safety. RESULTS: A total of 108 patients were enrolled between September 2016 and May 2020. The median age was 61 years, ECOG 1 score accounts for 67.6%, the rest were ECOG 0. A total of 502 cycles were completed, with an average of 4.6 cycles and a median of 4 cycles. 108 patients were evaluated, with an objective response rate of 17.6%, and disease control rate of 76.9%. The median follow-up time was 27 months (range:3.1-61.0 m) at data cut-off on March 2023. Median progression-free survival was 4.9 months (95% CI 4.1-5.7) and median overall survival was 13.1 months (95% CI 12.2-15.5). The most common adverse events that were elevated are alanine aminotransferase increased, aspartate aminotransferase increased, fatigue, diarrhoea, neutrocytopenia, thrombocytopenia, hypohemoglobin, and leukocytopenia. Most of the adverse events were Grade I/II, which were relieved after symptomatic treatment, and there were no treatment-related cardiotoxicities and deaths. CONCLUSIONS: The combination of raltitrexed and irinotecan as second-line treatment for mCRC could be a reliable option after failure of standard 5-Fu-first-line chemotherapy in locally advanced or metastatic colorectal cancers, especially for patients with 5-FU intolerance (cardiac events or DPD deficiency patients). TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03053167, registration date was 14/2/2017.

Exosomal PD-L1 Retains Immunosuppressive Activity and is Associated with Gastric Cancer Prognosis.

BACKGROUND: A recent study showed that circulating exosomal PD-L1 is an effective predictor for anti-PD-1 therapy in melanomas. Exosomal PD-L1 induced immunosuppression microenvironments in cancer patients. However, its prognostic value and immunosuppressive effect in gastric cancer (GC) were poorly understood. METHODS: We retrospectively evaluated the prognostic value of exosomal PD-L1 and soluble PD-L1 in preoperative plasma of 69 GC patients. The correlation between exosomal PD-L1 and the T cell counts or cytokine in the plasma was evaluated in 31 metastatic GC patients before chemotherapy. RESULTS: Overall survival (OS) was significantly lower in the high exosomal PD-L1 group compared with the low exosomal PD-L1 group (P = 0.004). Exosomal PD-L1 was an independent prognostic factor in GC (n = 69, 95% confidence interval = 1.142-7.669, P = 0.026). However, soluble PD-L1 showed no correlation with OS (P = 0.139). Additionally, exosomal PD-L1 in the plasma samples of 31 metastatic GC patients was negatively associated with CD4+ T cell count (P = 0.001, R = - 0.549), CD8+ T-cell count (P = 0.054, R = - 0.349), and granzyme B (P = 0.002, R = - 0.537), indicating that exosomal PD-L1 was associated with immunosuppressive status of GC patients. GC cells also secreted exosomal PD-L1 and were positively associated with the amount of PD-L1 in corresponding GC cell lines. Besides, exosomal PD-L1 significantly decreased T-cell surface CD69 and PD-1 expressions compared with soluble PD-L1 due to its stable and MHC-I expression. CONCLUSIONS: Overall, exosomal PD-L1 predicts the worse survival and reflects the immune status in GC patients, resulting from a stronger T-cell dysfunction due to its stable and MHC-I expression.

The dynamic monitoring of CEA in response to chemotherapy and prognosis of mCRC patients.

BACKGROUND: The role of carcinoembryonic antigen (CEA) change patterns in tumor response and long-term outcome is unclear. This study aimed to investigate the correlation between changes in CEA levels and tumor response as a potential prognostic model. METHODS: CEA levels were determined from baseline to progression. A χ2 test was used to assess the correlation between CEA changes and tumor response. Univariate and multivariate COX models were used to explore the correlation of CEA changes to progression-free survival (PFS) and overall survival (OS). RESULTS: All 114 patients were divided into five groups according to CEA change pattern (A: patients had an initial fast CEA decrease that then turned into a slow increase; B: patients had an initial slow CEA decrease that then turned to a slow increase; C: patients had a continually slow CEA increase; D: patients had a continually fast CEA increase; E: patients had an initial fast CEA decrease that then turned into a fast increase). Patients in Group A had the longest OS and PFS while Group E patients had the shortest OS. Baseline to week 12 and week 12 to week 18 change rates were consistent with tumor response and progression, respectively. An increase in CEA level by ≥2.7% from week 12 to 18 was an independent negative prognostic factor of OS. CONCLUSIONS: CEA changes mirror the tumor response to first-line chemotherapy and are associated with prognosis. CEA monitoring may be a substitute for computed tomography during the CEA stable period of treatment.

MicroRNA-29b-2-5p inhibits cell proliferation by directly targeting Cbl-b in pancreatic ductal adenocarcinoma.

BACKGROUND: MicroRNAs can be used in the prognosis of malignancies; however, their regulatory mechanisms are unknown, especially in pancreatic ductal adenocarcinoma (PDAC). METHODS: In 120 PDAC specimens, miRNA levels were assessed by quantitative real time polymerase chain reaction (qRT-PCR). Then, the role of miR-29b-2-5p in cell proliferation was evaluated both in vitro (Trypan blue staining and cell cycle analysis in the two PDAC cell lines SW1990 and Capan-2) and in vivo using a xenograft mouse model. Next, bioinformatics methods, a luciferase reporter assay, Western blot, and immunohistochemistry (IHC) were applied to assess the biological effects of Cbl-b inhibition by miR-29b-2-5p. Moreover, the relationship between Cbl-b and p53 was evaluated by immunoprecipitation (IP), Western blot, and immunofluorescence. RESULTS: From the 120 PDAC patients who underwent surgical resection, ten patients with longest survival and ten with shortest survival were selected. We found that high miR-29b-2-5p expression was associated with good prognosis (p = 0.02). The validation cohort confirmed miR-29b-2-5p as an independent prognostic factor in PDAC (n = 100, 95% CI = 0.305-0.756, p = 0.002). Furthermore, miR-29b-2-5p inhibited cell proliferation, induced cell cycle arrest, and promoted apoptosis both in vivo and in vitro. Interestingly, miR-29b-2-5p directly bound the Cbl-b gene, down-regulating its expression and reducing Cbl-b-mediated degradation of p53. Meanwhile, miR-29b-2-5p expression was negatively correlated with Cbl-b in PDAC tissues (r = - 0.33, p = 0.001). CONCLUSIONS: Taken together, these findings indicated that miR-29b-2-5p improves prognosis in PDAC by targeting Cbl-b to promote p53 expression, and would constitute an important prognostic factor in PDAC.

Pretreatment platelet-to-lymphocyte ratio is associated with the response to first-line chemotherapy and survival in patients with metastatic gastric cancer.

BACKGROUND: Several studies have shown that platelet-to-lymphocyte ratio (PLR) is a prognostic factor for various cancers. However, there is no study about the role of PLR in predicting response to first-line chemotherapy of metastatic gastric cancer. Therefore, this study aimed to establish whether PLR is associated with the response to first-line chemotherapy and survival in patients with metastatic gastric cancer. METHODS: We enrolled 273 patients diagnosed with metastatic gastric cancer. The best cut-off value of PLR to predict chemotherapeutic response was chosen by receiver operating characteristic (ROC) curve analysis. Prognostic significance was determined using the log-rank test and multivariate Cox regression analysis. RESULTS: Based on the cut-off value of PLR, patients were divided into a low PLR group and high PLR group. In logistic regression analysis, the low PLR group had a significantly higher disease control rate than the high PLR group had (91.3 vs 76.1%, P=.002), and PLR was an independent risk factor for response to first-line chemotherapy (odds ratio [OR]: 3.256; 95% confidence interval [CI]: 1.521-6.969; P=.002). The low PLR group had significantly longer overall survival (OS) than the high PLR group had (13.4 vs 9.2 months; P=.020). Multivariate survival analysis showed that PLR was significantly associated with OS [hazard ratio (HR): 1.002; 95% CI: 1.000-1.003; P=.020]. CONCLUSIONS: Pre-treatment PLR is associated with the response rate to first-line chemotherapy and survival outcomes in patients with metastatic gastric cancer.

Role of patient-, tumor- and systemic inflammatory response-related factors in predicting survival of patients with node-negative gastric cancer.

It is currently unclear as to which patients with node-negative gastric cancer can benefit from adjuvant chemotherapy. This study aimed to develop a prognostic model based on patient-, tumor-, and host-related factors to stratify high-risk patients eligible for adjuvant therapy. Correlations of clinicopathological and hematological features with overall survival were analyzed using a Cox model. A score to identify risk classes was derived from hazard ratios in multivariate analysis. In all, 436 patients with node-negative gastric cancer (stage pT1-4aN0M0) were analyzed in this study. Multivariate analysis showed that age, depth of invasion, and neutrophil-lymphocyte ratio were independent prognostic indicators of overall survival, and a prognostic model was developed using these significant factors. Patients were stratified into three risk groups with significant differences in the 3-year survival rates (98.5%, 91.6%, and 70.7%, respectively; p < 0.001) according to their scores. The prognostic model improved the predictive accuracy of postoperative 3-year survival rate by 7% when compared with the pathological T stage. A model based on age, depth of invasion, and neutrophil-lymphocyte ratio is more effective than traditional staging systems in predicting the prognosis of node-negative gastric cancer. High-risk patients could be considered for adjuvant therapy.

A novel function of hepatocyte growth factor in the activation of checkpoint kinase 1 phosphorylation in colon cancer cells.

The ATR/checkpoint kinase 1 (Chk1) pathway plays an essential role in modulating the DNA damage response and homologous recombination. Particularly, Chk1 phosphorylation is related to cancer prognosis and therapeutic resistance. Some receptor tyrosine kinases participate in the regulation of Chk1 phosphorylation; however, the effect of hepatocyte growth factor (HGF) on Chk1 phosphorylation is unknown. In the present study, we demonstrated that HGF moderately activated Chk1 phosphorylation in colon cancer cells by upregulating TopBP1 and RAD51, and promoting TopBP1-ATR complex formation. Furthermore, AKT activity, which was promoted by HGF, served as an important mediator linking HGF/MET signaling and Chk1 phosphorylation. Depleting AKT activity attenuated basal expression of p-Chk1 and HGF-induced Chk1 activation. Moreover, AKT activity directly regulated TopBP1 and RAD51 expression. AKT inhibition suppressed HGF-induced upregulation of TopBP1 and RAD51, and enhanced TopBP1/ATR complex formation. Our results show that HGF was involved in regulating Chk1 phosphorylation, and further demonstrate that AKT activity was responsible for this HGF-induced Chk1 phosphorylation. These findings might potentially result in management of prognosis and therapeutic sensitivity in cancer therapy.

Efficacy of Bevacizumab in the First-Line Treatment of Patients with RAS Mutations Metastatic Colorectal Cancer: a Systematic Review and Network Meta-Analysis.

BACKGROUND/AIMS: Whether patients with RAS mutation metastatic colorectal cancer (mCRC) obtain benefits from bevacizumab added to first-line chemotherapy remains unclear. METHODS: PubMed, Cochrane Systematic Reviews, the Cochrane Collaboration Central Register of Controlled Clinical Trials, ClinicalTrials.gov, and the American Society of Clinical Oncology and European Society for Medical Oncology databases were searched to identify abstracts for randomized controlled trials (RCTs) evaluating the efficacy of bevacizumab for the first-line treatment of patients with RAS mutations mCRC from inception to the end of April 2016. Hazard ratios (HRs) for overall survival (OS) and progression-free survival (PFS) were estimated. RESULTS: Ten eligible papers reporting six RCTs were included. In the network meta-analysis of patients with RAS mutations, bevacizumab + chemotherapy prolonged PFS compared with chemotherapy alone (HR 0.75, 95% CI 0.51-1.10), but the difference was not statistically significant. Bevacizumab + chemotherapy did not prolong OS compared with chemotherapy alone (HR 1.10, 95% CI 0.73-1.66). CONCLUSION: There was insufficient evidence to definitively state that patients with RAS mutations mCRC could benefit from bevacizumab combined with chemotherapy as first-line treatment.

Celecoxib sensitizes gastric cancer to rapamycin via inhibition of the Cbl-b-regulated PI3K/Akt pathway.

Mammalian target of rapamycin (mTOR) has emerged as a new potential therapeutic target for gastric cancer. However, a phase III clinical trial found that monotherapy with the mTOR inhibitor everolimus did not significantly improve the overall survival of patients with advanced gastric cancer. This has led to the exploration of more effective combinatorial regimens to enhance the effectiveness of mTOR inhibitors. Here, we demonstrate that Akt phosphorylation is increased in the rapamycin-resistant gastric cancer cell lines MGC803 and SGC7901. We further show that combined treatment with celecoxib and rapamycin results in an additive inhibitory effect on the growth of gastric cancer cells through suppression of rapamycin-induced Akt activation. Moreover, celecoxib upregulated the expression of the ubiquitin ligase casitas B-lineage lymphoma-b (Cbl-b). Knockdown of Cbl-b significantly attenuated celecoxib-mediated inhibition of Akt phosphorylation and impaired the additive anticancer effect of celecoxib and rapamycin. Our results suggest that celecoxib-mediated upregulation of Cbl-b is responsible, at least in part, for the additive antitumor effect of celecoxib and rapamycin via inhibition of rapamycin-induced Akt activation.

Early initiation of fluorouracil-based adjuvant chemotherapy improves survival in patients with resectable gastric cancer.

PURPOSE: Several clinical trials have suggested that adjuvant chemotherapy improves the survival of patients with resected gastric cancer, but the optimal time at which to initiate post-operative adjuvant chemotherapy has not been studied. This study investigated the association between time to adjuvant chemotherapy and survival in gastric cancer. METHODS: We retrospectively identified 266 patients with stage IB-IIIC gastric cancer who received fluorouracil-based adjuvant chemotherapy after radical gastrectomy. Overall survival (OS) was compared between patients grouped according to time from surgery to adjuvant chemotherapy (<45 and ≥45 days). The Cox proportional hazards model was used to analyze the effects of time to initiation of chemotherapy and other clinical covariates on survival. RESULTS: Of 266 patients, 141 (53%) started adjuvant chemotherapy within 45 days after surgery and 125 (47%) started adjuvant chemotherapy more than 45 days after surgery. The 3-year OS rates were 81.2 and 65.8% for patients starting chemotherapy within 45 days and after 45 days, respectively (p=0.006). Multivariate analysis identified early initiation of adjuvant chemotherapy, completion of the planned chemotherapy, and early-stage disease as favorable prognostic factors in terms of OS (p<0.05). Subgroup analysis suggested that starting chemotherapy within 45 days after surgery was associated with significant OS benefit compared with initiation of chemotherapy after 45 days from surgery in most subgroups. CONCLUSIONS: This retrospective analysis suggests that delaying adjuvant chemotherapy for longer than 45 days after surgery may be associated with poorer survival in patients with resected gastric cancer.

Cbl-b accelerates trypsin-induced cell detachment through ubiquitination and degradation of proline-rich tyrosine kinase 2.

Trypsin is a digestive enzyme that is widely used for cell detachment, which is the first stage of tumor metastasis. Recent studies show that adhesion-related kinases are involved in cell detachment. Proline-rich tyrosine kinase 2 (Pyk2) is a crucial kinase in the regulation of cell adhesion and detachment. However, the effect of Pyk2 on cell detachment is controversial. In the present study, we found that Pyk2 expression was rapidly decreased after trypsin treatment in gastric cancer, breast cancer, colon cancer, lung cancer, and human gastric epithelial cells. Knockdown of Pyk2 accelerated cell detachment. Furthermore, lysosome inhibitor NH4CL suppressed cell detachment and increased ubiquitination of Pyk2. Cbl-b is a type of E3 ubiquitin ligase that interacted with Pyk2, reduced the expression of Pyk2, and promoted trypsin-induced degradation of Pyk2. These findings suggest that Cbl-b promoted cell detachment through mono-ubiquitination of Pyk2. Our data provide a new insight into the role of Cbl-b in cell detachment.

Trastuzumab and oxaliplatin exhibit a synergistic antitumor effect in HER2-postive gastric cancer cells.

Trastuzumab has recently been recommended for the treatment of epidermal growth factor receptor-2 (HER2)-positive advanced gastric cancer in combination with the capecitabine/cisplatin (XP) versus continuous infusion of 5-fluorouracil/cisplatin (FP) regimen. However, it is unclear whether it is rational to combine trastuzumab with other chemotherapy regimens in clinical practice. Our study demonstrates that adding trastuzumab to oxaliplatin, a commonly used third-generation platinum derivative, increases the antitumor effect in vitro. In MTT assays, combination treatment with oxaliplatin and trastuzumab significantly decreased the concentration of oxaliplatin required to induce 50% growth inhibition in HER2-positive gastric cancer cells. Further investigation revealed that the trastuzumab-oxaliplatin combination induced cell cycle arrest and decreased expression of both p-AKT and p-ERK. Notably, this treatment combination induced downregulation of the excision repair cross-complementation group 1 (ERCC1) protein, which is involved in the key repair process of the oxaliplatin-DNA platinum adduct at the protein level. Similar changes were also observed in HER2-positive breast cancer cells. These findings suggest that trastuzumab synergizes the cytotoxic effect of oxaliplatin on HER2-positive gastric and breast cancer cells. Our study provides preclinical evidence for the optimization of this combination regimen in the treatment of HER2-positive gastric cancer patients.

Case report: A case of rare metastasis of gastric cancer to the axillary lymph node metastasis treated with combination immunotherapy.

Lymph node (LN) metastasis is a common mode of metastasis in advanced gastric cancer (GC), while axillary LN metastasis infrequently occurs in GC. There are few reports on this rare type of metastasis - especially its clinicopathological features - and systemic treatment are unclear. We describe a case of GC with extensive metastasis, including the rare axillary LN metastasis. The patient achieved partial response of optimal efficacy, who was treated with combination immunotherapy as second-line treatment for nearly two years. The potential mechanisms were revealed by clinical and immune characteristics, such as high expression of PD-L1, high tumor mutational burden (TMB-H), Epstein-Barr virus (EBV) positive and CD8+ tumor-infiltrating lymphocyte positive.

Cbl-b enhances sensitivity to 5-fluorouracil via EGFR- and mitochondria-mediated pathways in gastric cancer cells.

5-Fluorouracil (5-FU) is an essential component of anticancer chemotherapy against gastric cancer. However, the response rate of single drug is still limited. The ubiquitin ligase Cbl-b is a negative regulator of growth factor receptor signaling and is involved in the suppression of cancer cell proliferation. However, whether Cbl-b could affect 5-FU sensitivity remains unclear. The present study showed that Cbl-b knockdown caused higher proliferation concomitant with the decrease of apoptosis induced by 5-FU treatment in gastric cancer cell. Further mechanism investigation demonstrated that Cbl-b knockdown caused significant increase of phosphorylation of EGFR, ERK and Akt, decrease of mitochondrial membrane potential, and increase of expression ratio of Bcl-2/Bax. These results suggest that Cbl-b enhances sensitivity to 5-FU via EGFR- and mitochondria-mediated pathways in gastric cancer cells.

Evaluation of second-line apatinib plus irinotecan as a treatment for advanced gastric adenocarcinoma or gastroesophageal conjunction adenocarcinoma: a prospective, multicenter phase II trial.

Objective: Apatinib and irinotecan are used as systematic therapies for advanced gastric adenocarcinoma (GAC) and gastroesophageal junction adenocarcinoma (GEJA), while the evidence for their combination as second-line therapy in these patients is limited. This study aimed to evaluate the efficacy and safety of second-line apatinib plus irinotecan for the treatment of GAC and GEJA. Methods: In this prospective, multicenter phase II clinical study, 28 patients with advanced GAC or GEJA who received second-line apatinib plus irinotecan were recruited. Results: In total, 1 (3.6%) patient achieved complete response, 7 (25.0%) patients achieved partial response, 13 (46.4%) patients had stable disease, and 4 (14.3%) patients showed progressive disease, while clinical response was not evaluable or not assessed in 3 (10.7%) patients. The objective response rate and disease control rate were 28.6% and 75.0%, respectively. Meanwhile, the median (95% confidence interval (CI)) progression-free survival (PFS) was 4.5 (3.9-5.1) months, and the median (95% CI) overall survival (OS) was 11.3 (7.4-15.1) months. By multivariate Cox regression analysis, male sex, liver metastasis, and peritoneal metastasis were independently associated with worse PFS or OS, while treatment duration ≥5 months was independently associated with better OS. In terms of the safety profile, 89.3% of patients experienced treatment-emergent adverse events of any grade, among which 82.1% of patients had grade 1-2 adverse events and 64.3% of patients had grade 3-4 adverse events. Conclusion: Apatinib plus irinotecan as second-line therapy achieves a good treatment response and satisfactory survival with tolerable safety in patients with advanced GAC or GEJA.

Construction of the prognostic model for small-cell lung cancer based on inflammatory markers: A real-world study of 612 cases with eastern cooperative oncology group performance score 0-1.

OBJECTIVES: This research aimed to explore the relationship between pre-treatment inflammatory markers and other clinical characteristics and the survival of small-cell lung cancer (SCLC) patients who received first-line platinum-based treatment and to construct nomograms for predicting overall survival (OS) and progression-free survival (PFS). METHODS: A total of 612 patients diagnosed with SCLC between March 2008 and August 2021 were randomly divided into two cohorts: a training cohort (n = 459) and a validation cohort (n = 153). Inflammatory markers, clinicopathological factors, and follow-up information of patients were collected for each case. Cox regression was used to conduct univariate and multivariate analyses and the independent prognostic factors were adopted to develop the nomograms. Harrell's concordance index (C-index) and time-dependent receiver operating characteristic curve were used to verify model differentiation, calibration curve was used to verify consistency, and decision curve analysis was used to verify the clinical application value. RESULTS: Our results showed that baseline C-reactive protein/albumin ratio, neutrophil/lymphocyte ratio, NSE level, hyponatremia, the efficacy of first-line chemotherapy, and stage were independent prognostic factors for both OS and PFS in SCLC. In the training cohort, the C-index of PFS and OS was 0.698 and 0.666, respectively. In the validation cohort, the C-index of PFS and OS was 0.727 and 0.747, respectively. The nomograms showed good predictability and high clinical value. Also, our new clinical models were superior to the US Veterans Administration Lung Study Group (VALG) staging for predicting the prognosis of SCLC. CONCLUSIONS: The two prognostic nomograms of SCLC including inflammatory markers, VALG stage, and other clinicopathological factors had good predictive value and could individually assess the survival of patients.

SOX8 promotes cetuximab resistance via HGF/MET bypass pathway activation in colorectal cancer.

AIM: Cetuximab is an essential drug for the treatment of wild-type K-RAS colorectal cancer (CRC). It improves the overall survival of patients. However, acquired resistance prevents its clinical efficacy. Tumor heterogeneity may be a nonnegligible reason for cetuximab resistance. We attempted to explore the corresponding molecular mechanism. METHODS: Cetuximab-resistant CRC cell RKO and cetuximab-sensitive CRC cell Caco-2 were applied in this study. Cells were centrifuged to determine the concentration in the culture supernatant (CS). MTT, EdU, and colony formation assays were utilized to evaluate cell survival and proliferation. Chromatin immunoprecipitation (ChIP) and promoter-luciferase reporter assays were employed to confirm the direct binding of transcription factors. Western blot and reverse transcription-polymerase chain reaction (RT-PCR) assays were used to detect the expression of molecular markers in the pathway. RESULTS: Hepatocyte growth factor (HGF) was up-regulated in RKO cell culture supernatant and induced cetuximab resistance in Caco-2 cells. SRY-Box Transcription Factor 8 (SOX8) bound to the promoter sequence of HGF. HGF activated the HGF/MET bypass pathway and induced cetuximab resistance in Caco-2 cells. CONCLUSION: The SOX8/HGF/MET axis played a crucial role in the communication between cetuximab-resistant cells and cetuximab-sensitive cells, inducing treatment resistance.

TRIM27 is an adverse prognostic biomarker and associated with immune and molecular profiles in right-sided colon cancer.

Right-sided colon cancer (RCC), as an independent tumor entity, shows a poor prognosis. It is imperative to detect immune microenvironment-related genes for predicting RCC patient prognosis and study their function in RCC. Tripartite motif-containing 27 (TRIM27) was identified as a risk signature from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) datasets by using weighted gene co-expression network analysis, differentially expressed analysis, and univariate Cox analysis. It predicted a poorer overall survival and increased lymph node metastasis, which were then validated in our 48 clinical samples. Using immunohistochemistry, TRIM27 was found to be highly expressed in both cancer cells and surrounding immunocytes, and its expression in tumor or immune cells both predicted a poorer prognosis. Thereafter, the functional mechanism, immune and molecular characteristics of TRIM27 were investigated using gene set enrichment analysis (GSEA), ESTIMATE, CIBERSORT, and gene set variation analysis (GSVA) at the single-cell, somatic mutation, and RNA-seq level. Patients with highly expressed TRIM27 presented lower CD4+ T cell infiltration and activation of the mTORC1/glycolysis pathway. In addition, patients with highly expressed TRIM27 were characterized by hypermetabolism, higher tumor purity, more BRAF mutation, and more chromosomal instability. Collectively, TRIM27 is an important immune-related prognostic biomarker in patients with RCC. It may function via activating the mTORC1/glycolysis pathway and suppressing CD4+ T cells. These results indicated that TRIM27 could be a promising therapeutic target in RCC.

ß-Elemene-induced autophagy protects human gastric cancer cells from undergoing apoptosis.

BACKGROUND: ß-Elemene, a compound found in an herb used in traditional Chinese medicine, has shown promising anti-cancer effects against a broad spectrum of tumors. The mechanism by which ß-elemene kills cells remains unclear. The aim of the present study is to investigate the anti-tumor effect of ß-elemene on human gastric cancer cells and the molecular mechanism involved. RESULTS: ß-Elemene inhibited the viability of human gastric cancer MGC803 and SGC7901 cells in a dose-dependent manner. The suppression of cell viability was due to the induction of apoptosis. A robust autophagy was observed in the cells treated with ß-elemene; it was characterized by the increase of punctate LC3 dots, the cellular morphology, and the increased levels of LC3-II protein. Further study showed that ß-elemene treatment up-regulated Atg5-Atg12 conjugated protein but had little effect on other autophagy-related proteins. PI3K/Akt/mTOR/p70S6K1 activity was inhibited by ß-elemene. Knockdown of Beclin 1 with small interfering RNA, or co-treatment with the autophagy inhibitor, 3-methyladenine or chlorochine enhanced significantly the antitumor effects of ß-elemene. CONCLUSIONS: Our data provides the first evidence that ß-elemene induces protective autophagy and prevents human gastric cancer cells from undergoing apoptosis. A combination of ß-elemene with autophagy inhibitor might thus be a useful therapeutic option for advanced gastric cancer.

Ubiquitin ligase c-Cbl is involved in tamoxifen-induced apoptosis of MCF-7 cells by downregulating the survival signals.

BACKGROUND: Tamoxifen (TAM) is a nonsteroidal antiestrogen that has been widely used in the treatment of breast cancer through its anti-estrogen activity. Recent studies show that TAM is cytotoxic to both estrogen receptor (ER)-positive and ER-negative cells via the induction of apoptosis. However, the molecular mechanisms of this effect are not well understood. In the present study, we investigated the roles of c-Src, ERK, AKT and c-Cbl ubiquitin ligases during TAM-induced apoptosis of MCF-7 cells. MATERIAL AND METHODS: MCF-7 cell proliferation and apoptosis were measured by 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, and flow cytometry, respectively. c-Cbl expression, and the activity of c-Src, ERK, AKT were assayed by Western blotting. Overexpression of the wild and the dominant-negative type of c-Cbl (70Z/Cbl) were achieved by transient transfection of plasmids encoding c-Cbl and 70Z/Cbl, respectively, and were confirmed by Western blotting. Statistical analysis was performed using the t-test, and a p-value <0.05 was considered to be statistically significant. RESULTS: A high concentration of TAM (25 µM) induced a time-dependent apoptosis of MCF-7 cells. ERK1/2 and AKT were activated during TAM-induced apoptosis. The ERK1/2 inhibitor PD98059, the PI3K/Akt inhibitor LY294002, and the c-Src inhibitor PP2 all enhanced TAM action. Moreover, the ubiquitin ligase c-Cbl was up-regulated during this process. Over-expression of c-Cbl significantly enhanced the apoptosis-inducing effects of TAM, while 70Z/Cbl suppressed the apoptosis-inducing effects of TAM. Further investigation revealed that, overexpression of c-Cbl significantly downregulated the c-Src protein levels and TAM-induced AKT activity. But 70Z/Cbl significantly upregulated TAM-induced ERK and AKT activity. CONCLUSIONS: This study demonstrates that c-Src, ERK, and AKT played a protective role during TAM-induced apoptosis, and that c-Cbl sensitized MCF-7 cells to TAM by modulating the expression of c-Src, and TAM-induced ERK and AKT activity.