A liquid biopsy signature of circulating extracellular vesicles-derived RNAs predicts response to first line chemotherapy in patients with metastatic colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) is one of the most threatening tumors in the world, and chemotherapy remains dominant in the treatment of metastatic CRC (mCRC) patients. The purpose of this study was to develop a biomarker panel to predict the response of the first line chemotherapy in mCRC patients. METHODS: Totally 190 mCRC patients treated with FOLFOX or XEOLX chemotherapy in 3 different institutions were included. We extracted the plasma extracellular vesicle (EV) RNA, performed RNA sequencing, constructed a model and generated a signature through shrinking the number of variables by the random forest algorithm and the least absolute shrinkage and selection operator (LASSO) algorithm in the training cohort (n = 80). We validated it in an internal validation cohort (n = 62) and a prospective external validation cohort (n = 48). RESULTS: We established a signature consisted of 22 EV RNAs which could identify responders, and the area under the receiver operating characteristic curve (AUC) values was 0.986, 0.821, and 0.816 in the training, internal validation, and external validation cohort respectively. The signature could also identify the progression-free survival (PFS) and overall survival (OS). Besides, we constructed a 7-gene signature which could predict tumor response to first-line oxaliplatin-containing chemotherapy and simultaneously resistance to second-line irinotecan-containing chemotherapy. CONCLUSIONS: The study was first to develop a signature of EV-derived RNAs to predict the response of the first line chemotherapy in mCRC with high accuracy using a non-invasive approach, indicating that the signature could help to select the optimal regimen for mCRC patients.

A2AR-mediated lymphangiogenesis via VEGFR2 signaling prevents salt-sensitive hypertension.

AIMS: Excess dietary sodium intake and retention lead to hypertension. Impaired dermal lymphangiogenesis and lymphatic dysfunction-mediated sodium and fluid imbalance are pathological mechanisms. The adenosine A2A receptor (A2AR) is expressed in lymphatic endothelial cells (LECs), while the roles and mechanisms of LEC-A2AR in skin lymphangiogenesis during salt-induced hypertension are not clear. METHODS AND RESULTS: The expression of LEC-A2AR correlated with lymphatic vessel density in both high-salt diet (HSD)-induced hypertensive mice and hypertensive patients. Lymphatic endothelial cell-specific A2AR knockout mice fed HSD exhibited 17 ± 2% increase in blood pressure and 17 ± 3% increase in Na+ content associated with decreased lymphatic density (-19 ± 2%) compared with HSD-WT mice. A2AR activation by agonist CGS21680 increased lymphatic capillary density and decreased blood pressure in HSD-WT mice. Furthermore, this A2AR agonist activated MSK1 directly to promote VEGFR2 activation and endocytosis independently of VEGF as assessed by phosphoprotein profiling and immunoprecipitation assays in LECs. VEGFR2 kinase activity inhibitor fruquintinib or VEGFR2 knockout in LECs but not VEGF-neutralizing antibody bevacizumab suppressed A2AR activation-mediated decrease in blood pressure. Immunostaining revealed phosphorylated VEGFR2 and MSK1 expression in the LECs were positively correlated with skin lymphatic vessel density and A2AR level in hypertensive patients. CONCLUSION: The study highlights a novel A2AR-mediated VEGF-independent activation of VEGFR2 signaling in dermal lymphangiogenesis and sodium balance, which might be a potential therapeutic target in salt-sensitive hypertension.

Calcipotriol abrogates cancer-associated fibroblast-derived IL-8-mediated oxaliplatin resistance in gastric cancer cells via blocking PI3K/Akt signaling.

Activation of vitamin D receptor (VDR) in cancer-associated fibroblasts (CAFs) has been implicated in hesitating tumor progression and chemoresistance of several human malignancies. Yet, the role of VDR in CAF-induced chemotherapy resistance of gastric cancer (GC) cells remains elusive. In this study we first conducted immunohistochemistry analysis on tissue microarrays including 88 pairs of GC and normal mucosa samples, and provided clinical evidence that VDR was mainly expressed in gastric mucous cells but almost invisible in CAFs, and VDR expression was negatively correlated with malignant clinical phenotype and advanced stages, low VDR expression confers to poor overall survival rate of patients with GC. In a co-culture system of primary CAFs and cancer cells, we showed that treatment of HGC-27 and AGS GC cells with VDR ligand calcipotriol (Cal, 500 nM) significantly inhibited CAF-induced oxaliplatin resistance. By using RNA-sequencing and Human Cytokine Antibody Array, we demonstrated that IL-8 secretion from CAFs induced oxaliplatin resistance via activating the PI3K/AKT pathway in GC, whereas Cal treatment greatly attenuated the tumor-supportive effect of CAF-derived IL-8 on GC cells. Taken together, this study verifies the specific localization of VDR in GC tissues and demonstrates that activation of VDR abrogates CAF-derived IL-8-mediated oxaliplatin resistance in GC via blocking PI3K/Akt signaling, suggesting vitamin D supplementation as a potential strategy of enhancing the anti-tumor effect of chemotherapy in GC.

Classification of colon adenocarcinoma based on immunological characterizations: Implications for prognosis and immunotherapy.

Accurate immune molecular typing is pivotal for screening out patients with colon adenocarcinoma (COAD) who may benefit from immunotherapy and whose tumor microenvironment (TME) was needed for reprogramming to beneficial immune-mediated responses. However, little is known about the immune characteristic of COAD. Here, by calculating the enrichment score of immune characteristics in three online COAD datasets (TCGA-COAD, GSE39582, and GSE17538), we identified 17 prognostic-related immune characteristics that overlapped in at least two datasets. We determined that COADs could be stratified into three immune subtypes (IS1-IS3), based on consensus clustering of these 17 immune characteristics. Each of the three ISs was associated with distinct clinicopathological characteristics, genetic aberrations, tumor-infiltrating immune cell composition, immunophenotyping (immune "hot" and immune "cold"), and cytokine profiles, as well as different clinical outcomes and immunotherapy/therapeutic response. Patients with the IS1 tumor had high immune infiltration but immunosuppressive phenotype, IS3 tumor is an immune "hot" phenotype, whereas those with the IS2 tumor had an immune "cold" phenotype. We further verified the distinct immune phenotype of IS1 and IS3 by an in-house COAD cohort. We propose that the immune subtyping can be utilized to identify COAD patients who will be affected by the tumor immune microenvironment. Furthermore, the ISs may provide a guide for personalized cancer immunotherapy and for tumor prognosis.

Dual HER2 Targeted Therapy With Pyrotinib and Trastuzumab in Refractory HER2 Positive Metastatic Colorectal Cancer: A Result From HER2-FUSCC-G Study.

BACKGROUND: Dual-HER2 targeted therapy has led to a promising antitumor effect in HER2 positive cancers including gastrointestinal cancer. The present data focus on patients with HER2 positive colorectal cancer who received pyrotinib and trastuzumab after failure to standard second-line treatment. METHODS: Patients diagnosed of HER2 positive refractory or metastatic colorectal cancer were enrolled to receive trastuzumab in combination with pyrotinib as third-line and beyond therapy. Trastuzumab was given as a loading dose at 8 mg/kg followed by 6mg/kg once every 3 weeks, and oral pyrotinib as 400 mg per day until progression. ORR was set as the primary endpoint. PFS and OS were set as a secondary endpoints. This trial is registered with Clinical Trial.gov, NCT04960943, and is ongoing. RESULTS: Between February 2020 to December 2021, 16 patients including 14 with RAS wild-type status were enrolled in this cohort. ORR was 50.0% in the overall population, and 57.1% in RAS wild-type patients. At a median follow-up of 11.2 months, median PFS and OS were 7.53 and 16.8 months, respectively. The RAS/BRAF wild-type patients had prolonged survival (PFS: 7.53 vs. 1.63 months, P = .02; OS: NR vs.4.13 months, P = .001) compared with RAS/BRAF mutant patients. The most common treatment-emergent adverse event (TEAE) reported is diarrhea. Five (31.3%) patients reported grade 3 TEAEs, and no death was reported. CONCLUSIONS: Trastuzumab in combination with pyrotinib demonstrated encouraging antitumor activity that translated to prolonged survival benefit in HER2 positive refractory or mCRC patients who are RAS wild-type with acceptable tolerance.

Human Epidermal Growth Factor Receptor 2 Overexpression and Amplification in Patients With Colorectal Cancer: A Large-Scale Retrospective Study in Chinese Population.

Background: Cumulative evidence in colorectal cancer (CRC) suggests that patients with human epidermal growth factor receptor 2 (HER2) overexpression or amplification can benefit from anti-HER2 therapy. The purpose of our study was to evaluate HER2 status and its correlation with clinicopathological characteristics and survival according to currently utilized HER2 diagnostic criteria in a large cohort of Chinese CRC patients. Methods: HER2 protein expression was tested by immunohistochemistry (IHC) in formalin-fixed, paraffin-embedded (FFPE) samples from 4,836 CRC patients in our institution. Breast cancer (BC) and gastroesophageal adenocarcinoma (GEA) criteria, as well as the HERACLES criteria, were used for the determination of HER2 status. Dual-color silver-enhanced in situ hybridization (DSISH) was performed in all IHC 2+~3+ cases determined by BC/GEA criteria. Results: The HER2 expression rate of IHC (1+~3+) was 7.01% (339/4,836) and 6.02% (291/4,836) in CRCs based on the BC/GEA criteria and the HERACLES criteria, respectively, while combined DSISH results in the HER2 amplification/overexpression ratio of 3.39% (164/4,836) in our cohort. HER2 expression detected by IHC was positively correlated with the female gender, whereas the HER2 overexpression/amplification showed no correlation with any clinicopathological parameter. In addition, no significant correlation was found between HER2 statuses and either disease-free survival or overall survival regardless of the evaluation criterion used. However, patients with HER2 1+ CRC showed a tendency of having the shortest overall survival as compared with any other group of patients according to the HERACLES criteria, and this trend has always existed in the rectal location, T3 stage, and TNM stage II, medium differentiation, and perineural invasion stratified group. Furthermore, the HER2 protein expression was significantly negatively correlated with RAS/BRAF mutations according to the HERACLES criteria. Conclusion: To our knowledge, this is the largest study of HER2 status in Asian patients with CRC. Our findings suggest that the current most commonly used HERACLES criteria might be too strict for patients with CRC. Future studies are needed to explore the most suitable criteria for screening CRC patients who could benefit from anti-HER2 therapy as much as possible.

Comprehensive molecular characterization and identification of prognostic signature in stomach adenocarcinoma on the basis of energy-metabolism-related genes.

BACKGROUND: Stomach adenocarcinoma (STAD) is a leading cause of cancer deaths, but its molecular and prognostic characteristics has never been fully illustrated. AIM: To describe a molecular evaluation of primary STAD and develop new therapies and identify promising prognostic signatures. METHODS: We describe a comprehensive molecular evaluation of primary STAD based on comprehensive analysis of energy-metabolism-related gene (EMRG) expression profiles. RESULTS: On the basis of 86 EMRGs that were significantly associated to patients' progression-free survival (PFS), we propose a molecular classification dividing gastric cancer into two subtypes: Cluster 1, most of which are young patients and display more immune and stromal cell components in tumor microenvironment and lower tumor priority; and Cluster 2, which show early stages and better PFS. Moreover, we construct a 6-gene signature that can classify the prognostic risk of patients after a three-phase training test and validation process. Compared with patients with low-risk score, patients with high-risk score had shorter overall survival. Furthermore, calibration and DCA analysis plots indicate the excellent predictive performance of the 6-gene signature, and which present higher robustness and clinical usability compared with three previous reported prognostic gene signatures. According to gene set enrichment analysis, gene sets related to the high-risk group were participated in the ECM receptor interaction and hedgehog signaling pathway. CONCLUSION: Identification of the EMRG-based molecular subtypes and prognostic gene model provides a roadmap for patient stratification and trials of targeted therapies.

Chidamide triggers BTG1-mediated autophagy and reverses the chemotherapy resistance in the relapsed/refractory B-cell lymphoma.

Rituximab/chemotherapy relapsed and refractory B cell lymphoma patients have a poor overall prognosis, and it is urgent to develop novel drugs for improving the therapy outcomes. Here, we examined the therapeutic effects of chidamide, a new histone deacetylase (HDAC) inhibitor, on the cell and mouse models of rituximab/chemotherapy resistant B-cell lymphoma. In Raji-4RH/RL-4RH cells, the rituximab/chemotherapy resistant B-cell lymphoma cell lines (RRCL), chidamide treatment induced growth inhibition and G0/G1 cell cycle arrest. The primary B-cell lymphoma cells from Rituximab/chemotherapy relapsed patients were sensitive to chidamide. Interestingly, chidamide triggered the cell death with the activation of autophagy in RRCLs, likely due to the lack of the pro-apoptotic proteins. Based on the RNA-seq and chromatin immunoprecipitation (ChIP) analysis, we identified BTG1 and FOXO1 as chidamide target genes, which control the autophagy and the cell cycle, respectively. Moreover, the combination of chidamide with the chemotherapy drug cisplatin increased growth inhibition on the RRCL in a synergistic manner, and significantly reduced the tumor burden of a mouse lymphoma model established with engraftment of RRCL. Taken together, these results provide a theoretic and mechanistic basis for further evaluation of the chidamide-based treatment in rituximab/chemotherapy relapsed and refractory B-cell lymphoma patients.

Apatinib for patients with metastatic biliary tract carcinoma refractory to standard chemotherapy: results from an investigator-initiated, open-label, single-arm, exploratory phase II study.

BACKGROUND: There is no standard therapy for metastatic biliary tract carcinoma (BTC) refractory to first-line chemotherapy. Apatinib, a VEGFR2 tyrosine kynase inhibitor, showed an activity against BTC xenografts in preclinical models. We conducted an exploratory study to evaluate the efficacy and safety of apatinib in patients with metastatic BTC. METHODS: This is a single-arm phase II study [ClinicalTrials.gov identifier: NCT03427242]. Eligible patients were aged 18 years or older; histologically confirmed metastatic BTC; refractory or intolerance to at least one chemotherapeutic regimen; no prior use of anti-angiogenic targeted drugs; Eastern Cooperative Oncology Group performance status of 0-2. Patients received oral apatinib 500 mg each day continuously until unacceptable toxicity or tumor progression. The primary endpoint was progress free survival (PFS). The secondary endpoint was overall survival (OS), objective response rate (ORR) and treatment safety. RESULTS: A total of 22 patients were recruited. All of them received apatinib medication. The median age was 63 (44-75) years old. Twenty patients received efficacy evaluation after treatment. The objective response rate (ORR) and disease control rate (DCR) were 15.0% and 60.0%, respectively. The median PFS was 2.73 months [95% confidence interval (CI): 1.74-3.72 months], with 6 months PFS rate of 27.3% (95% CI: 8.7-45.9%). The median OS was 4.81 months (95% CI: 3.16-10.9 months), with 12 months OS rate of 36.4% (95% CI: 16.2-56.6%). Nine out of 22 patients (40.9%) had grade 3/4 adverse events. The most common grade 3/4 adverse events were hand-foot skin syndrome [three (13.6%) patients] and hypertension [two (9.1%) patients]. No treatment-related death occurred. CONCLUSIONS: For patients with metastatic BTC, apatinib showed an anti-tumor activity with acceptable safety, which deserves the further clinical trial.This trial was prospectively registered on ClinicalTrials.gov [NCT03427242]. Date of first patient enrollment: 26 January 2018. Date of registration (date of first posted): 9 February 2018.

Tumor Response to Irinotecan is Associated with IL-10 Expression Level in Metastatic Colorectal Cancer-Results from mCRC Biomarker Study.

PURPOSE: Metastatic colorectal cancer (mCRC) is a leading cause of cancer-related death. Resistance to chemotherapy is the main reason for the failure of the treatment of mCRC. IL-10 has been reported to decrease after surgery and increase after mCRC reoccurrence. The role of IL-10 in chemotherapy drug resistance of mCRC is not well elucidated. PATIENTS AND METHODS: The retrospective study recruited 264 mCRC patients between January 2012 and December 2016 (NCT03532711). All the enrolled patients received an oxaliplatin-containing or irinotecan-containing regimen. The expression level of IL-10 in 232 patients' plasma and 68 patients' tumor tissue was examined. The relationships between IL-10 and clinicopathological characteristics were analyzed. Kaplan-Meier method and Cox regression were used to evaluate the prognostic impact of IL-10. RESULTS: The median concentration of IL-10 was 7.60 pg/mL before treatment and 11.08 pg/mL after treatment, which suggested that IL-10 level was significantly increased by treatment with a chemotherapeutic regimen (p = 0.000). By utilizing univariate and multivariate Cox proportional hazard analyses, we found that low IL-10 level in plasma was significantly associated with improved overall survival (OS) of mCRC patients treated with irinotecan-containing regimen-with optimal cutoff value of 5.525pg/mL, respectively (p =0.002). In addition, the low IL-10 expression level in tumor tissue was significantly associated with the improved OS for the irinotecan-containing regimen (p = 0.023). CONCLUSION: Our study demonstrated that IL-10 could act as a prognostic biomarker for mCRC patients undergoing irinotecan-containing chemotherapy.

GCNT4 is Associated with Prognosis and Suppress Cell Proliferation in Gastric Cancer.

BACKGROUND: GCNT4 is a member of the glucosaminyl (N-acetyl) transferases family that has been implicated in multiple human malignancies. However, the role of GCNT4 in gastric cancer (GC) is unknown. In this present study, we aimed to explore the role and clinicopathological correlation of GCNT4 in GC. MATERIALS AND METHODS: We first evaluated the dysregulation of GCNT4 in The Cancer Genome Atlas (TCGA) and then we performed RT-qPCR and immunohistochemistry to validate the results in a cohort of in-house patients. The clinicopathological correlation and function of GCNT4 in GC were also analysed. RESULTS: GCNT4 was found to be significantly downregulated in GC. In addition, GCNT4 expression correlated with tumour depth, nervous invasion and pathological tumor-node-metastasis (pTNM) stage. Moreover, lower GCNT4 levels conferred poor overall survival (OS) and disease-free survival (DFS) to GC patients. Multivariate Cox regression analysis revealed that GCNT4 protein expression is an independent prognostic factor for OS in patients with GC. Further functional experimental results revealed that overexpression of GCNT4 appears to halt GC cell proliferation and the cell cycle. CONCLUSION: Altogether, these findings indicated that GCNT4 regulates the GC cell cycle and have important implications for the selection of therapeutic targets to prevent tumour proliferation.

Severe loss of visceral fat and skeletal muscle after chemotherapy predicts poor prognosis in metastatic gastric cancer patients without gastrectomy.

Background: The influence of body composition parameters in cancer prognosis attracted researchers' attention. This study investigated the role of visceral fat and skeletal muscle in the prognosis and efficacy of chemotherapy in metastatic gastric cancer (MGC). Methods: This study included MGC patients without gastrectomy treated with EOF regimen (epirubicin, oxaliplatin and fluorouracil), who participated in a Phase II clinical trial (NCT00767377) with available PACS image data. The visceral fat area (VFA) and skeletal muscle area (SMA) were measured using standard computed tomography (CT). Results: A total of 46 patients were enrolled in the study. Patients with low baseline VFA and SMA had significantly shorter PFS and OS. In addition, the loss of VFA and SMA also predicts significantly shorter PFS and OS. A prognostic index that included two risk factors, severe loss of VFA and SMA, was used to categorize the patients into two groups: good-risk group (0 risk factors), poor-risk group (1 or 2 risk factors). Compared with the good-risk group, the poor-risk group displayed a 3.562-fold-increased risk of progression [hazard ratio (HR) 3.652, 95 % CI 1.653-7.678; P =0.001] and 2.859-fold-increased risk of death [hazard ratio (HR) 2.859, 95 % CI 1.271-6.434; P =0.011]. Conclusion: Low baseline VFA and SMA, as well as the severe loss of VFA and SMA predict poor prognosis for MGC patients treated by EOF regimen. In patients with severe loss of VFA and/or SMA after 2-cycle chemotherapy, the decision of subsequent chemotherapy should be made after deliberate consideration.

Spatiotemporal Changes in Checkpoint Molecule Expression.

Immune checkpoint inhibitors (ICIs), particularly PD-1/PD-L1 blockade, have led to therapeutic breakthrough in patients with advanced malignancy, covering the lung, breast, gastrointestinal, head and neck, urinary system, lymphoma, and solid tumor harboring MSI/dMMR. In certain cancer types, the expression level of immune checkpoint molecule will be required if the immune-based approaches are considered, especially the PD-L1 expression. However, in other types, survival benefit has been proven regardless of PD-L1 expression. It raises a question of how to select patients for immune therapy and whether the expression of immune checkpoint molecules will be optimal biomarkers. Before answering this question, a comprehensive map for the expression of immune checkpoint molecules is needed. In this chapter, we describe our current knowledge on the spatiotemporal changes in the expression of checkpoint molecules. We discuss the different frequencies of expression depending on tumor types and stages, the different patterns between primary and metastatic tumors, as well as the change of expression before and after treatment. The expression of PD-L1 has been most studied, but the threshold that separate "positive" and "negative" PD-L1 expressions and the consistency of testing platform remain under debate. Better understanding on the tumor microenvironment and expression of checkpoint molecules will help to identify patients who will benefit from checkpoint blockade therapy.

Decreased mean platelet volume predicts poor prognosis in metastatic colorectal cancer patients treated with first-line chemotherapy: results from mCRC biomarker study.

BACKGROUND: Metastatic colorectal cancer (mCRC) is a major cause of death of malignant tumor and the valuable prognostic biomarker for chemotherapy is crucial in decreasing mortality. Previous studies have proved the prognostic value of the mean platelet volume (MPV) in survival of primary operable CRC patients. However, the prognostic impact of MPV in mCRC is still unclear. In this study, we aimed to clarify the prognostic role of MPV in mCRC undergoing standard first-line chemotherapy. METHODS: From January 2012 to December 2016, we conducted a retrospective clinical study included 264 mCRC patients (NCT03532711). All the enrolled patients received the standard oxaliplatin-based or irinotecan-based chemotherapy. The association between the baseline MPV and clinicopathological features were examined. RESULTS: Univariate analysis revealed that decreased MPV, the platelet counts (PLT), platelet-to-lymphocyte ratio (PLR) and the platelet crit (PCT) were significantly associated with inferior overall survival (OS) (p < 0.05). On multivariate analysis, elevated PLR was significant prognostic factors for OS, with hazard ratios of (HR:1.006, 95% CI:1.001-1.011, p = 0.01) while MPV was not, respectively (p < 0.05). CONCLUSIONS: Our study demonstrated that the baseline MPV level may act as a predictive factor for survival in mCRC patients undergoing standard chemotherapy. TRIAL REGISTRATION: This study was retrospectively registered in date May the 20th 2018. The registration number (TRN) of this study was NCT03532711 .

Plasma microRNA-based signatures to predict 3-year postoperative recurrence risk for stage II and III gastric cancer.

Our aim was to identify plasma microRNA (miRNA)-based signatures to predict 3-year postoperative recurrence risk for patients with stage II and III gastric cancer (GC), so as to provide insights for individualized adjuvant therapy. Plasma miRNA expression was investigated in three phases, involving 407 patients recruited from three centers. ABI miRNA microarray and TaqMan Low Density Array were adopted in the discovery phase to identify potential miRNAs. Quantitative reverse-transcriptase polymerase chain reaction was used to assess the expression of selected miRNAs. Logistic regression models were constructed in the training set (n = 170) and validated in the validation set (n = 169). Receiver operating characteristic analyses, survival analyses and subgroup analyses were further used to assess the accuracy of the models. We identified a 7 miRNA classifier and 7miR + pathological factors index that provided high predictive accuracy of GC recurrence (area under the curve = 0.725 and 0.841 in the training set; and 0.627 and 0.771 in the validation set). High-risk patients defined by the signatures had significantly shorter disease-free survival and overall survival than low-risk patients. The 7 miRNA classifier is an independent prognostic factor, and could add predictive value to traditional prognostic factors. Subgroup analyses revealed the satisfactory performance persisted regardless of stage, and the two models both displayed high accuracy in stage IIA patients. In conclusion, identified microRNA signature may potentially provide some additional benefit for prediction of disease recurrence in patients with stage II and III GC.

Differential microRNA expression profiling in primary tumors and matched liver metastasis of patients with colorectal cancer.

BACKGROUND: Liver metastasis is common in patients with colorectal cancer (CRC), and is correlated with poor outcome. MicroRNAs (miRNAs) are small non-coding RNAs involved in cancer development and progression, but their role in CRC liver metastasis has not been extensively investigated. RESULTS: Thirteen miRNAs were deregulated in pCRCs compared to their matched liver metastases. Seventeen miRNAs were chosen for validation, which confirmed significantly reduced expression of miR-99b-5p, miR-377 and miR-200c and increased expression of miR-196b-5p in the tissue of liver metastasis. Furthermore, miR-200c and miR-196b-5p were positively correlated with shorter overall survival in pCRC patients with liver metastasis. MATERIALS AND METHODS: Firstly, affymetrix microarrays involving 1036 miRNAs were performed in two pairs of primary CRCs (pCRCs) and their matched liver metastases. Secondly, validation of the results was carried out on an independent cohort of 48 pairs of pCRCs and matched liver metastases using quantitative real-time polymerase chain reaction assay. CONCLUSIONS: We discovered a pCRC liver metastasis-specific miRNA panel including miR-377, miR-99b-5p, miR-200c and miR-196b-5p through intensive validation. These miRNAs may function as prognostic factors in patients with metastatic CRC.

MicroRNA-421 regulated by HIF-1α promotes metastasis, inhibits apoptosis, and induces cisplatin resistance by targeting E-cadherin and caspase-3 in gastric cancer.

Hypoxia and dysregulation of microRNAs (miRNAs) have been identified as crucial factors in carcinogenesis. However, the potential mechanisms of HIF-1α and miR-421 in gastric cancer have not been well elucidated. In this study, we found that miR-421 was up-regulated by HIF-1α. Overexpression of miR-421 promoted metastasis, inhibited apoptosis, and induced cisplatin resistance in gastric cancer in vivo and in vitro. E-cadherin and caspase-3 were identified as targets of miR-421. Besides, relative mRNA expression of miR-421 was significantly increased in gastric cancer tumor tissues compared with non-tumor tissues in a cohort of gastric cancer specimens (n=107). The expression of miR-421 was higher in advanced gastric cancers compared with localized ones. Moreover, Kaplan-Meier analysis illustrated that those patients with low levels of miR-421 had a significant longer overall survival (p = 0.006) and time to relapse (p = 0.007). Therefore, miR-421 could serve as an important prognostic marker and a potential molecular target for therapy in gastric cancer.

Implication of combined PD-L1/PD-1 blockade with cytokine-induced killer cells as a synergistic immunotherapy for gastrointestinal cancer.

Cytokine-induced killer (CIK) cells represent a realistic approach in cancer immunotherapy with confirmed survival benefits in the context of metastatic solid tumors. However, therapeutic effects are limited to a fraction of patients. In this study, immune-resistance elements and ideal combination therapies were explored. Initially, phenotypic analysis was performed to document CD3, CD56, NKG2D, DNAM-1, PD-L1, PD-1, CTLA-4, TIM-3, 2B4, and LAG-3 on CIK cells. Upon engagement of CIK cells with the tumor cells, expression of PD-1 on CIK cells and PD-L1 on both cells were up-regulated. Over-expression of PD-L1 levels on tumor cells via lentiviral transduction inhibited tumoricidal activity of CIK cells, and neutralizing of PD-L1/PD-1 signaling axis could enhance their tumor-killing effect. Conversely, blockade of NKG2D, a major activating receptor of CIK cells, largely caused dysfunction of CIK cells. Functional study showed an increase of NKG2D levels along with PD-L1/PD-1 blockade in the presence of other immune effector molecule secretion. Additionally, combined therapy of CIK infusion and PD-L1/PD-1 blockade caused a delay of in vivo tumor growth and exhibited a survival advantage over untreated mice. These results provide a preclinical proof-of-concept for simultaneous PD-L1/PD-1 pathways blockade along with CIK infusion as a novel immunotherapy for unresectable cancers.

Identification of short-form RON as a novel intrinsic resistance mechanism for anti-MET therapy in MET-positive gastric cancer.

Despite the promising results from initial studies, there are significant limitations in the application of MET-targeted therapy in gastric cancer. Intrinsic resistance is one of the major obstacles. The aim of this study is to identify the responsible receptor tyrosine kinases (RTKs) that determine the unresponsiveness of MET inhibitor in MET-positive gastric cancer. through an RNA-interference-based functional screen targeting most human RTKs, we identified that activation of the fibroblast growth factor receptor 2 (FGFR2) and recepteur d'origine nantais (RON) pathways attenuated MET inhibitor-induced suppression of cell proliferation and migration. Notably, in the two forms of RON pathway activation, only upregulation of short-form RON (sf-RON), but not stimulation of full length RON with macrophage stimulating protein, conferred MET inhibitor resistance in vitro and in vivo. Furthermore, the profile of the gastric cancer samples observed that sf-RON was frequently upregulated in MET-positive gastric cancer. Our findings indicate that activation of the sf-RON signaling pathway represents a novel mechanism underlying MET inhibitor unresponsiveness. A combination strategy with drugs targeting both RON and MET pathways is believed to improve the efficacy of MET-targeted therapy.

miRNA-99b-5p suppresses liver metastasis of colorectal cancer by down-regulating mTOR.

Liver metastasis is common in patients diagnosed with colorectal cancer (CRC), and is also correlated with poor outcome. In this study we screened the different expression profiles of microRNAs (miRNAs) on the development of liver metastasis in CRC patients. miR-99b-5p was found to be more than 6-fold higher in primary tumors than in matched liver metastases (P = 0.007). Expression of miR-99b-5p in primary tumors of patients with stage III CRC without liver metastases was higher than in CRC patients with liver metastases (P = 0.028). Up-regulated miR-99b-5p was associated with longer overall survival (P = 0.01). Besides, miR-99b-5p silencing in miR-99b-5p-positive CRC cell lines promoted cell migration and up-regulated mTOR, and vice versa. In addition, luciferase assays demonstrated that miR-99b-5p functioned as a tumor suppressor by targeting mTOR. Taken together, our results demonstrate thatmiR-99b-5p is differently expressed in primary CRC and liver metastasis and functions as a tumor-suppressive microRNA in metastatic CRC. The miR-99b-5p-mTOR axis may serve as a prognostic factor and therapeutic target for anti-metastatic therapy in CRC patients.