A novel signature of seven aging-related genes for risk stratification, prognosis prediction and benefit evaluation of chemotherapy, and immunotherapy in elderly patients with lung adenocarcinoma.

Background: Aging, a multifaceted biological process, is thought to be associated with lung adenocarcinoma (LUAD) development and progression. However, it is unclear whether aging-related genes (ARGs) can predict tumor risk, chemotherapy and immunotherapy benefits, and prognosis in LUAD patients at different ages. Methods: Gene expression datasets and clinical information of LUAD patients were downloaded from TCGA and GEO database. Univariate and multivariate Cox regression, and lasso algorithm were employed to identify the ARG signatures. Patients were stratified into high-risk and low-risk groups to evaluate the predictive accuracy using Kaplan-Meier curves, ROC curves, and time-dependent AUC. A nomogram was established to predict the survival probability. GSEA revealed potential pathways, and CIBERSORT indicated different immunologic status. TIDE score was used to predict the potential tumor response to immune checkpoint inhibitors, and GDSC was employed to evaluate the sensitivity of chemotherapeutic drugs. The correlation of TIDE score and patient age, as well as that of ARGs and patient age was investigated. And cell Culture and RT-qPCR for external validation for key gene. Results: A novel gene signature based on seven ARGs was established, including BMP15, CD79A, CDKN3, CDX2, COL1A1, DKK1, and GRIK2. Our model demonstrated exceptional prediction accuracy for elderly LUAD patients of 71-90 years old. A nomogram model was constructed to predict the survival probability, and the C-index value was 0.737, indicating our prognostic nomogram model has high accuracy. Through external RT-qPCR validation, we found that CD79A expression in H1299 was higher than that of BEAS-2B. And novel immunotherapy and chemotherapy regimens were accordingly proposed for the elderly LUAD patients. Conclusion: We identified a novel gene signature based on seven ARGs for risk stratification, prognosis prediction and benefit evaluation of immunotherapy and chemotherapy in elderly LUAD patients.

Pancreatic cancer cells hijack tumor suppressive microRNA-26a to promote radioresistance and potentiate tumor repopulation.

Pancreatic cancer is one of the most lethal cancers with significant radioresistance and tumor repopulation after radiotherapy. As a type of short non-coding RNA that regulate various biological and pathological processes, miRNAs might play vital role in radioresistance. We found by miRNA sequencing that microRNA-26a (miR-26a) was upregulated in pancreatic cancer cells after radiation, and returned to normal state after a certain time. miR-26a was defined as a tumor suppressive miRNA by conventional tumor biology experiments. However, transient upregulation of miR-26a after radiation significantly promoted radioresistance, while stable overexpression inhibited radioresistance, highlighting the importance of molecular dynamic changes after treatment. Mechanically, transient upregulation of miR-26a promoted cell cycle arrest and DNA damage repair to promote radioresistance. Further experiments confirmed HMGA2 as the direct functional target, which is an oncogene but enhances radiosensitivity. Moreover, PTGS2 was also the target of miR-26a, which might potentiate tumor repopulation via delaying the synthesis of PGE2. Overall, this study revealed that transient upregulation of miR-26a after radiation promoted radioresistance and potentiated tumor repopulation, highlighting the importance of dynamic changes of molecules upon radiotherapy.

Transforming cancer cells for long-term living with cancer: An inspiring new approach.

Cancer is the leading cause of human death and imposes a huge health burden. Currently, no matter what advanced therapeutic modalities or technologies are applied, it is still peculiarly rare for most cancers to be radically cured whereas therapy resistance and tumor recurrence are ever so common. The long-standing cytotoxic therapy is hard to achieve long-term tumor control, and produces side-effects or even promotes cancer progression. With growing understandings of tumor biology, we came to realize that it is possible to transform but not kill cancer cells to achieve long-term living with cancer, and directly altering cancer cells is a promising way. Remarkably, tissue microenvironment is involved in the fate determination of cancer cells. Of note, leveraging cell competition to combat malignant or therapy-resistant cells shows some therapeutic potentials. Furthermore, modulating tumor microenvironment to restore a normal state might help to transform cancer cells. Especially, reprogramming cancer-associated fibroblasts, and tumor-associated macrophages, or normalization of tumor vessel, tumor immune microenvironment, and tumor extracellular matrix or their combinations, et al., revealed some long-term therapeutic benefits. Despite the massive challenges ahead, it would be possible to transform cancer cells for long-term cancer control and living with cancer longevously. The related basic researches and corresponding therapeutic strategies are also ongoing.

An anoikis-related gene signature predicts prognosis and reveals immune infiltration in hepatocellular carcinoma.

Background: Hepatocellular carcinoma (HCC) is a global health burden with poor prognosis. Anoikis, a novel programmed cell death, has a close interaction with metastasis and progression of cancer. In this study, we aimed to construct a novel bioinformatics model for evaluating the prognosis of HCC based on anoikis-related gene signatures as well as exploring the potential mechanisms. Materials and methods: We downloaded the RNA expression profiles and clinical data of liver hepatocellular carcinoma from TCGA database, ICGC database and GEO database. DEG analysis was performed using TCGA and verified in the GEO database. The anoikis-related risk score was developed via univariate Cox regression, LASSO Cox regression and multivariate Cox regression, which was then used to categorize patients into high- and low-risk groups. Then GO and KEGG enrichment analyses were performed to investigate the function between the two groups. CIBERSORT was used for determining the fractions of 22 immune cell types, while the ssGSEA analyses was used to estimate the differential immune cell infiltrations and related pathways. The "pRRophetic" R package was applied to predict the sensitivity of administering chemotherapeutic and targeted drugs. Results: A total of 49 anoikis-related DEGs in HCC were detected and 3 genes (EZH2, KIF18A and NQO1) were selected out to build a prognostic model. Furthermore, GO and KEGG functional enrichment analyses indicated that the difference in overall survival between risk groups was closely related to cell cycle pathway. Notably, further analyses found the frequency of tumor mutations, immune infiltration level and expression of immune checkpoints were significantly different between the two risk groups, and the results of the immunotherapy cohort showed that patients in the high-risk group have a better immune response. Additionally, the high-risk group was found to have higher sensitivity to 5-fluorouracil, doxorubicin and gemcitabine. Conclusion: The novel signature of 3 anoikis-related genes (EZH2, KIF18A and NQO1) can predict the prognosis of patients with HCC, and provide a revealing insight into personalized treatments in HCC.

Anticancer Benefit of Metformin in Patients With Early-Stage Pancreatic Cancer: A Retrospective Cohort Study.

Background: Epidemiologic studies have produced conflicting results on the effects of metformin on pancreatic cancer. This study aimed to observe and analyze whether metformin use is associated with better prognosis in pancreatic cancer. Materials and Methods: In this retrospective cohort study, all baseline data were retrieved from The Chinese Medicine Information Retrieval System (https://dc.wzhospital.cn/vpn/index.html) of The First Affiliated Hospital of Wenzhou Medical University. Survival data were collected by follow-up visits and medical records. Overall survival was the primary endpoint, while progression-free survival and disease-free survival were secondary endpoints. Progression or recurrence was assessed with radiologic images. Results: Seventy-six metformin users and 92 metformin nonusers diagnosed with pancreatic cancer from 2012 to 2020 in this hospital were enrolled. The adjusted hazard ratio for overall survival for metformin users was 0.50 (95% confidence interval = 0.33-0.76), where median overall survival was 16.0 months for metformin users versus 11.5 months for metformin nonusers. The protective effect was also found by analyzing progression-free survival (adjusted hazard ratio = 0.39, 95% confidence interval = 0.18-0.86) and disease-free survival (adjusted hazard ratio = 0.30, 95% confidence interval = 0.14-0.68). In the subgroup analysis, metformin use had a statistically significant association with prolongation of survival in stage I to II pancreatic cancer patients (hazard ratio = 0.47, 95% confidence interval = 0.25-0.91), but not for advanced tumor stage (hazard ratio for IV stage = 0.62, 95% confidence interval = 0.33-1.19), after adjustment for other risk factors. Conclusion: Metformin use is related to favorable survival outcomes of pancreatic cancer, especially in early tumor stage.

Genomic Instability-Related LncRNA Signature Predicts the Prognosis and Highlights LINC01614 Is a Tumor Microenvironment-Related Oncogenic lncRNA of Papillary Thyroid Carcinoma.

BACKGROUND: Genomic instability (GI) is among the top ten characteristics of malignancy. Long non-coding RNAs (lncRNAs) are promising cancer biomarkers that are reportedly involved in GI. So far, the clinical value of GI-related lncRNAs (GIlncs) in papillary thyroid cancer (PTC) has not been clarified. METHODS: Integrative analysis of lncRNA expression and somatic mutation profiles was performed to identify GIlncs. Analysis of differentially expressed lncRNAs in the group with high- and low- cumulative number of somatic mutations revealed significant GIlncs in PTC. Univariate and multivariate Cox proportional hazard regression analyses were performed to identify hub-GIlncs. RESULTS: A computational model based on four lncRNAs (FOXD2-AS1, LINC01614, AC073257.2, and AC005082.1) was identified as a quantitative index using an in-silicon discovery cohort. GILS score was significantly associated with poor prognosis, as validated in the TCGA dataset and further tested in our local RNA-Seq cohort. Moreover, a combination of clinical characteristics and the composite GILS-clinical prognostic nomogram demonstrates satisfactory discrimination and calibration. Furthermore, the GILS score and FOXD2-AS1, LINC01614, AC073257.2, and AC005082.1 were also associated with driver mutations and multiple clinical-pathological variables, respectively. Moreover, RNA-Seq confirmed the expression patterns of FOXD2-AS1, LINC01614, AC073257.2, and AC005082.1 in PTC and normal thyroid tissues. Biological experiments demonstrated that downregulated or overexpressed LINC01614 affect PTC cell proliferation, migration, and invasion in vitro. Activation of the stromal and immune cell infiltration was also observed in the high LINC01614 group in the PTC microenvironment. CONCLUSION: In summary, we identified a signature for clinical outcome prediction in PTC comprising four lncRNAs associated with GI. A better understanding of the GI providing an alternative evaluation of the progression risk of PTC. Our study also demonstrated LINC01614 as a novel oncogenic lncRNA and verified its phenotype in PTC.

Expression levels of chemokine (C-X-C motif) ligands CXCL1 and CXCL3 as prognostic biomarkers in rectal adenocarcinoma: evidence from Gene Expression Omnibus (GEO) analyses.

Rectal cancer is a life­threatening disease worldwide. Chemotherapy resistance is common in rectal adenocarcinoma patients and has unfavorable survival outcomes; however, its related molecular mechanisms remain unknown. To identify genes related to the initiation and progression of rectal adenocarcinoma, three datasets were obtained from the Gene Expression Omnibus database. In total, differentially expressed genes were analyzed from 294 tumor and 277 para-carcinoma samples from patients with rectal cancer. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes functions were investigated. Cytoscape software and MicroRNA Enrichment Turned Network were applied to construct a protein-protein interaction network of the dependent hub genes and related microRNAs. The Oncomine database was used to identify hub genes. Additionally, Gene Expression Profiling Interactive Analysis was applied to determine the RNA expression level. Tumor immune infiltration was assessed using the Tumor Immune Estimation Resource database. The expression profiles of hub genes between stages, and their prognostic value, were also evaluated. During this study, data from The Cancer Genome Atlas were utilized. In rectal adenocarcinoma, four hub genes including CXCL1, CXCL2, CXCL3, and GNG4 were highly expressed at the gene and RNA levels. The expression of CXCL1, CXCL2, and CXCL3 was regulated by has-miR-1-3p and had a strong positive correlation with macrophage and neutrophil. CXCL2 and CXCL3 were differentially expressed at different tumor stages. High expression levels of CXCL1 and CXCL3 predicted poor survival. In conclusion, the CXCL1 and CXCL3 genes may have potential for prognosis and molecular targeted therapy of rectal adenocarcinoma.

MicroRNA-7 modulates cellular senescence to relieve gemcitabine resistance by targeting PARP1/NF-κB signaling in pancreatic cancer cells.

Senescence is activated in response to gemcitabine to prevent the propagation of cancer cells. However, there is little evidence on whether senescence is involved in gemcitabine resistance in pancreatic cancer. Increasing evidence has demonstrated that microRNAs (miRs) are potential regulators of cellular senescence. The present study aimed to investigate whether aberrant miR-7 expression modulated senescence to influence pancreatic cancer resistance to chemotherapy. In the present study, cell senescence assay, ALDEFLUOR™ assay, luciferase reporter assay, flow cytometry, quantitative PCR, immunohistochemistry and western blot analysis were performed to explore the association between senescence and gemcitabine therapy response, and to clarify the underlying mechanisms. The present study revealed that gemcitabine-induced chronically existing senescent pancreatic cells possessed stemness markers. Therapy-induced senescence led to gemcitabine resistance. Additionally, it was found that miR-7 expression was decreased in gemcitabine-resistant pancreatic cancer cells, and that miR-7 acted as an important regulator of cellular senescence by targeting poly (ADP-ribose) polymerase 1 (PARP1)/NF-κB signaling. When miR-7 expression was restored, it was able to sensitize pancreatic cancer cells to gemcitabine. In conclusion, the present study demonstrated that miR-7 regulated cellular senescence and relieved gemcitabine resistance by targeting the PARP1/NF-κB axis in pancreatic cancer cells.

LAGE3 correlates with tumorigenic immune infiltrates in the clear cell renal cell carcinoma microenvironment.

OBJECTIVE: Clear cell renal cell carcinoma (ccRCC) is the most common type of kidney tumor worldwide. The role of LAGE3 (L Antigen Family Member 3) in ccRCC has not been widely reported. In this study, we explored the clinical significances and biological functions of LAGE3 in ccRCC. METHODS: The RNA-seq data and the corresponding clinical information of the patients with ccRCC were extracted from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. ESTIMATE, quanTiseq, and xCell algorithms were used to estimate the immune infiltration levels in the ccRCC microenvironment. RESULTS: We found that overexpression of LAGE3 was associated with adverse clinical-pathological factors, and correlated with poor prognosis in multiple ccRCC cohorts. Multivariate analysis indicated that LAGE3 was an independent survival determinant in patients with ccRCC, whereas functional enrichment analysis suggested that LAGE3 may regulate humoral immune response, immunoglobulin complex, and receptor-ligand activity. Further, tumor microenvironment analysis based on different algorithms indicated LAGE3 was positively associated with the immune activity and infiltrating levels of different immune cells. Particularly, LAGE3 expression had a positive impact on different steps of the cancer-immunity cycle. CONCLUSION: The present findings disclose that LAGE3 could be an independent survival predictor, and might contribute to developing novel ccRCC immunological treatment strategies.

MicroRNA-7 as a Potential Biomarker for Prognosis in Pancreatic Cancer.

MicroRNAs play critical roles in tumor progression. Our recent study has indicated that microRNA-7 (miR-7) impairs autophagy-derived pools of glucose to suppress the glycolysis in pancreatic cancer progression. However, the roles of miR-7 in clinical significance and chemoresistance of pancreatic cancer remain unexplored. The aim of this study was to assess the expression of miR-7 in patients with pancreatic cancer and to evaluate the possibility of its usage as a prognostic molecular biomarker. MicroRNA array-based quantification analysis of 372 miRNAs was compared in serum between pancreatic cancer and healthy individuals, gemcitabine-sensitive and gemcitabine-resistance patients. We identified miR-7 showed the potential predictive power for gemcitabine-sensitive patients with pancreatic cancer. Then, the results were validated in pancreatic tissue microarray and The Cancer Genome Atlas (TCGA) dataset, demonstrating that lower miR-7 expression was correlated with more advanced tumor stages and worse prognosis in pancreatic cancer. The Cox proportional-hazards model analysis identified miR-7 to be an independent variable for prediction of the survival. Furthermore, the mechanistic exploration suggested the clinical significance of miR-7 involved its interference effect on autophagy and glycolysis in pancreatic cancer using pancreatic cancer tissue microarrays and TCGA data. Therefore, the results of the present study provide evidences that low microRNA-7 expression may contribute to tumor progression and poor prognosis in pancreatic cancer.

Dark Side of Cytotoxic Therapy: Chemoradiation-Induced Cell Death and Tumor Repopulation.

Accelerated tumor repopulation following chemoradiation is often observed in the clinic, but the underlying mechanisms remain unclear. In recent years, dying cells caused by chemoradiation have attracted much attention, and they may manifest diverse forms of cell death and release complex factors and thus orchestrate tumor repopulation cascades. Dying cells potentiate the survival of residual living tumor cells, remodel the tumor microenvironment, boost cell proliferation, and accelerate cancer cell metastasis. Moreover, dying cells also mediate the side effects of chemoradiation. These findings suggest more caution when weighing the benefits of cytotoxic therapy and the need to accordingly develop new strategies for cancer treatment.

Dying tumor cell-derived exosomal miR-194-5p potentiates survival and repopulation of tumor repopulating cells upon radiotherapy in pancreatic cancer.

BACKGROUND: Tumor repopulation is a major cause of radiotherapy failure. Previous investigations highlighted that dying tumor cells played vital roles in tumor repopulation through promoting proliferation of the residual tumor repopulating cells (TRCs). However, TRCs also suffer DNA damage after radiotherapy, and might undergo mitotic catastrophe under the stimulation of proliferative factors released by dying cells. Hence, we intend to find out how these paradoxical biological processes coordinated to potentiate tumor repopulation after radiotherapy. METHODS: Tumor repopulation models in vitro and in vivo were used for evaluating the therapy response and dissecting underlying mechanisms. RNA-seq was performed to find out the signaling changes and identify the significantly changed miRNAs. qPCR, western blot, IHC, FACS, colony formation assay, etc. were carried out to analyze the molecules and cells. RESULTS: Exosomes derived from dying tumor cells induced G1/S arrest and promoted DNA damage response to potentiate survival of TRCs through delivering miR-194-5p, which further modulated E2F3 expression. Moreover, exosomal miR-194-5p alleviated the harmful effects of oncogenic HMGA2 under radiotherapy. After a latent time, dying tumor cells further released a large amount of PGE2 to boost proliferation of the recovered TRCs, and orchestrated the repopulation cascades. Of note, low-dose aspirin was found to suppress pancreatic cancer repopulation upon radiation via inhibiting secretion of exosomes and PGE2. CONCLUSION: Exosomal miR-194-5p enhanced DNA damage response in TRCs to potentiate tumor repopulation. Combined use of aspirin and radiotherapy might benefit pancreatic cancer patients.

Folate-conjugated herpes simplex virus for retargeting to tumor cells.

BACKGROUND: Herpes simplex virus type 1 (HSV-1)-mediated oncolytic therapy is a promising cancer treatment modality. However, viral tropism is considered to be one of the major stumbling blocks to the development of HSV-1 as an anticancer agent. METHODS: The surface of oncolytic HSV-1 G207 was covalently modified with folate-poly (ethylene glycol) conjugate (FA-PEG). The specificities and tumor targeting efficiencies of modified or unmodified G207 particles were analyzed by a real-time polymerase chain reaction at the level of cell attachment and entry. Immune responses were assessed by an interleukin-6 release assay from RAW264.7 macrophages. Biodistribution and in vivo antitumoral activity after intravenous delivery was evaluated in BALB/c nude mice bearing subcutaneous KB xenograft tumors. RESULTS: FA-PEG-HSV exhibited enhanced targeting specificity for folate receptor over-expressing tumor cells and had lower immunogenicity than the unmodified HSV. In vivo, the FA-PEG-HSV group revealed an increased anti-tumor efficiency and tumor targeting specificity compared to the naked HSV. CONCLUSIONS: These results indicate that folate-conjugated HSV G207 presents a folate receptor-targeted oncolytic virus with a potential therapeutic value via retargeting to tumor cells.

Up-regulation of L Antigen Family Member 3 Associates With Aggressive Progression of Breast Cancer.

The role of L Antigen Family Member 3 (LAGE3) in breast cancer (BC) has not been sufficiently studied. In this study, we explored the clinical value and biological functions of LAGE3 in BC. Comprehensive analysis of LAGE3 was carried out on The Cancer Genome Atlas, Molecular Taxonomy of Breast Cancer International Consortium and Gene Expression Omnibus datasets. Results showed that LAGE3 expression was higher in BC tissues than in normal breast tissues of public datasets and our local cohort. Moreover, its expression was higher in BC patients with larger tumor size, significant lymph node metastasis, higher tumor grade, and more advanced disease stage. High expression of LAGE3 was correlated with poor prognosis, and LAGE3 could independently predict survival of BC patients. Functional enrichment analysis revealed a correlation between LAGE3 expression and biochemical metabolism and immune-related terms and cancer-related pathways. Analysis of tumor microenvironment indicated that LAGE3 expression was associated with the immune cell infiltration and anti-cancer immunity cycle. LAGE3 expression was higher in triple-negative breast cancer (TNBC) compared to hormone receptor-positive BC, but not HER2-positive subtype. Suppression of LAGE3 expression inhibited the proliferation and induced apoptosis of TNBC cell lines. Besides, the down-regulation of LAGE3 attenuated the migration and invasion but reduced the expression level of epithelial-mesenchymal-transition related proteins in TNBC cell lines. In conclusion, this study demonstrated for the first time that LAGE3 promotes the progression of BC. Therefore, it may be a potential diagnostic and prognostic biomarker, as well as a treatment target for BC.

The effect of the primary tumor location on the survival of colorectal cancer patients after radical surgery.

Background and Objectives: Colorectal cancer is one of the most common cancers and the leading cause of cancer-related death worldwide. The impact of the primary tumor location on the prognosis of patients with colorectal cancer has long been a concern, but studies have led to conflicting conclusions. Methods: In total, 465 colorectal cancer patients who received radical surgery were reviewed in this study. Enrolled patients were divided into two groups according to the tumor location. Disease-free survival (DFS) and overall survival (OS) were analyzed via the Kaplan-Meier method. A Cox regression model was employed to evaluate the independent prognostic factors for DFS and OS. Results: The right colorectal cancer (RCC) and left colorectal cancer (LCC) groups comprised 202 and 140 patients, respectively. Univariate and multivariate analyses revealed that the tumor location and TNM stage were independent predictors of DFS and OS. Subgroup analyses by stage demonstrated that there were significant differences in DFS and OS between patients with stage II and III RCC and LCC, but not for those with stage I colorectal cancer. Conclusions: Patients with stage II and III LCC had better survival than those with RCC. However, this improvement in DFS and OS was not observed in patients with stage I colorectal cancer.

Induction chemotherapy plus concurrent chemoradiotherapy versus induction chemotherapy plus volumetric modulated arc therapy alone in the treatment of stage II-IVB nasopharyngeal carcinoma patients: a retrospective controlled study.

BACKGROUND: In the era of intensity-modulated radiotherapy (IMRT), the role of additional concurrent chemotherapy (CC) to radiotherapy (RT) after induction chemotherapy (IC) compared to IC followed by RT alone remains unclear for stage II-IVB nasopharyngeal carcinoma (NPC) patients. The aim of this study was to evaluate the efficacy and toxicities of IC/RT and IC/CCRT in the treatment of NPC with volumetric modulated arc therapy (VMAT). METHODS: From January 2012 to March 2016, a total of 217 NPC patients were retrospectively assessed. Of the 217 patients, 139 patients received IC followed by VMAT alone and 78 patients received IC plus CCRT. Overall survival (OS), progression-free survival (PFS) and toxicities were assessed. RESULTS: The 5-year OS, PFS rates were 57.5%, 41.8% and 47.8%, 38.4% for the IC/RT and IC/CCRT arms, respectively, without significant difference in survival between the two groups (both p > 0.05). Multivariate analysis indicated that treatment modality (IC/RT vs. IC/CCRT) was not an independent prognostic factor for OS or PFS. Grade 3-4 leukopenia/neutropenia (3.60% vs. 20.51%, p < 0.001), gastrointestinal disorder (nausea/vomiting/diarrhea, 2.16% vs. 41.03%, p < 0.001), mucositis (29.50% vs. 47.44%, p = 0.01) and xerostomia (34.53% vs. 48.72%, p = 0.04) were more frequent in the IC/ CCRT arm than in the IC/RT arm during VMAT. CONCLUSIONS: No significant difference in OS and PFS was observed between IC plus VMAT alone and IC/CCRT in the treatment of stage II-IVB NPC patients, however, more side effects were observed in the IC/CCRT arm.

microRNA-193a stimulates pancreatic cancer cell repopulation and metastasis through modulating TGF-ß2/TGF-ßRIII signalings.

BACKGROUND: Pancreatic cancer characterizes high recurrence and poor prognosis. In clinical practice, radiotherapy is widely used for pancreatic cancer treatment. However, the outcome remains undesirable due to tumor repopulation and following recurrence and metastasis after radiation. So, it is highly needed to explore the underlying molecular mechanisms and accordingly develop therapeutic strategies. Our previous studies revealed that dying cells from chemoradiation could stimulate repopulation of surviving pancreatic cancer cells. However, we still knew little how dying cells provoke pancreatic cancer cell repopulation. We herein would explore the significance of TGF-ß2 changes and investigate the modulation of microRNA-193a (miR-193a), and identify their contributions to pancreatic cancer repopulation and metastasis. METHODS: In vitro and in vivo repopulation models were established to mimic the biological processes of pancreatic cancer after radiation. Western blot, real-time PCR and dual-luciferase reporter assays were accordingly used to detect miR-193a and TGF-ß2/TGF-ßRIII signalings at the level of molecular, cellular and experimental animal model, respectively. Flow cytometry analysis, wound healing and transwell assay, vascular endothelial cell penetration experiment, and bioluminescence imaging were employed to assessthe biological behaviors of pancreatic cancer after different treatments. Patient-derived tumor xenograft (PDX) mice models were established to evaluate the therapeutic potential of miR-193a antagonist on pancreatic cancer repopulation and metastasis after radiation. RESULTS: miR-193a was highly expressed in the irradiated pancreatic cancer dying cells, accordingly elevated the level of miR-193a in surviving cells, and further promoted pancreatic cancer repopulation and metastasis in vitro and in vivo. miR-193a accelerated pancreatic cancer cell cycle and stimulated cell proliferation and repopulation through inhibiting TGF-ß2/TGF-ßRIII/SMADs/E2F6/c-Myc signaling, and even destroyed normal intercellular junctions and promoted metastasis via repressing TGF-ß2/TGF-ßRIII/ARHGEF15/ABL2 pathway. Knockdown of miR-193a or restoration of TGF-ß2/TGF-ßRIII signaling in pancreatic cancer cells was found to block pancreatic cancer repopulation and metastasis after radiation. In PDX models, the treatment in combination with miR-193a antagonist and radiation was found to dramatically inhibit pancreatic cancer cell repopulation and metastasis, and further improved the survival after radiation. CONCLUSIONS: Our findings demonstrated that miR-193a stimulated pancreatic cancer cell repopulation and metastasis through modulating TGF-ß2/TGF-ßRIII signalings, and miR-193a might be a potential therapeutic target for pancreatic cancer repopulation and metastasis.

MicroRNA-7 inhibits cell proliferation of chronic myeloid leukemia and sensitizes it to imatinib in vitro.

MicroRNA is a large class of non-coding small RNA that exerts critical roles in many physiological processes including cell proliferation. MicroRNA-7 (miR-7) has been considered as a tumor suppressor in most malignant tumors versus a tumor promoter in some other ones. However, its role in chronic myeloid leukemia remains unknown. Herein, we found that K562 cell proliferation was largely suppressed when it was stably transfected with miR-7. In accordance with that, apoptosis was also significantly upregulated in miR-7 stably-transfected K562 cells. Moreover, we found that miR-7-overexpressed K562 cells were far more sensitive to imatinib than controls. Further investigations showed that the ABL1 was a direct target of miR-7. Expression level of BCR-ABL and the activity of its downstream PI3K/AKT pathway were significantly reduced in miR-7-transfected cells. Taken together, our results showed that miR-7 inhibited proliferation and promoted apoptosis in K562 cells, and miR-7 might help to sensitize them to imatinib through BCR-ABL/PI3K/AKT signaling in chronic myeloid leukemia.

microRNA-7 impairs autophagy-derived pools of glucose to suppress pancreatic cancer progression.

Pancreatic cancer commonly addicts to aerobic glycolysis, and abnormally activates autophagy to adapt the stringent metabolic microenvironment. microRNA-7 (miR-7) was supposed to modulate various gastrointestinal cancer progression. We wonder whether miR-7 could destroy the reprogrammed metabolic homeostasis in pancreatic cancer via modulating the level of autophagy, and further affect tumor proliferation and survival. Herein, we first reported that pancreatic cancer could take advantage of autophagy as a survival strategy to provide essential glucose required for glycolysis metabolism. Of note, under the stressful tumor microenvironment, miR-7 could repress autophagy through up-regulation of LKB1-AMPK-mTOR signaling, and directly targeting the stages of autophagy induction and vesicle elongation to reduce the supply of intracellular glucose to glycolysis metabolism. Furthermore, miR-7 inhibited pancreatic cancer cell proliferation and metastasis in vitro and in vivo. Consistently, lentivirus-mediated miR-7 effectively reduced the growth of patient-derived xenograft by interfering glycolysis via inhibition of autophagy. Together, these data suggested miR-7 might function as an important regulator to impair autophagy-derived pools of glucose to suppress pancreatic cancer progress. Hence, miR-7 might be a potential therapeutic target in pancreatic cancer.