Increased response to TPF chemotherapy promotes immune escape in hypopharyngeal squamous cell carcinoma

Background: There is an urgent need to identify which patients would benefit from TPF chemotherapy in hypopharyngeal squamous cell carcinoma (HPSCC) and to explore new combinations to improve the treatment effect. Materials and methods: Gene-expression profiles in 15 TPF-sensitive patients were compared to 13 resistant patients. Immunohistochemistry (IHC) was performed to detect CD8⁺ T cells in 28 samples. Patient-Derived Tumor Xenograft (PDX) model and IHC were used to verify markers that optimize treatment for HPSCC. Results: Through RNA sequencing 188 genes were up-regulated in TPF chemotherapy-resistant (CR) tissues were involved in T cell activation, while 60 down-regulated genes were involved in glycolysis. Gene set enrichment analysis (GSEA) showed that chemotherapy-sensitive (CS) group upregulation of the pathways of glycolysis, while immune response was downregulated. CIBERSORT, MCP-counter, and IHC proved that most immune cells including CD8⁺ T cells in the CR significantly higher than that in CS group. Among the 16 up-regulated genes in CS had close associations, the most significant negative correlation between the gene level and CD8⁺ T cells existed in SEC61G. SEC61G was related to glycolysis, which was transcriptionally regulated by E2F1, and participated in antigen degradation through ubiquitin-dependent protein catabolic process. Palbociclib, combined with Cetuximab decreased the tumor burden and significantly suppressed the expression of E2F1 and SEC61G while activating MHC-I in PDX model. Conclusion: Enhanced glycolysis promoted immune escape, but increased response to TPF chemotherapy. SEC61G was the center of the molecular network and targeting the E2F1/SEC61G pathway increased the expression level of MHC-I.

Knockdown of RRM1 with Adenoviral shRNA Vectors to Inhibit Tumor Cell Viability and Increase Chemotherapeutic Sensitivity to Gemcitabine in Bladder Cancer Cells

RRM1-an important DNA replication/repair enzyme-is the primary molecular gemcitabine (GEM) target. High RRM1-expression associates with gemcitabine-resistance in various cancers and RRM1 inhibition may provide novel cancer treatment approaches. Our study elucidates how RRM1 inhibition affects cancer cell proliferation and influences gemcitabine-resistant bladder cancer cells. Of nine bladder cancer cell lines investigated, two RRM1 highly expressed cells, 253J and RT112, were selected for further experimentation. An RRM1-targeting shRNA was cloned into adenoviral vector, Ad-shRRM1. Gene and protein expression were investigated using real-time PCR and western blotting. Cell proliferation rate and chemotherapeutic sensitivity to GEM were assessed by MTT assay. A human tumor xenograft model was prepared by implanting RRM1 highly expressed tumors, derived from RT112 cells, in nude mice. Infection with Ad-shRRM1 effectively downregulated RRM1 expression, significantly inhibiting cell growth in both RRM1 highly expressed tumor cells. In vivo, Ad-shRRM1 treatment had pronounced antitumor effects against RRM1 highly expressed tumor xenografts (p < 0.05). Moreover, combination of Ad-shRRM1 and GEM inhibited cell proliferation in both cell lines significantly more than either treatment individually. Cancer gene therapy using anti-RRM1 shRNA has pronounced antitumor effects against RRM1 highly expressed tumors, and RRM1 inhibition specifically increases bladder cancer cell GEM-sensitivity. Ad-shRRM1/GEM combination therapy may offer new treatment options for patients with GEM-resistant bladder tumors.

The lncRNA XIST/miR-125b-2-3p axis modulates cell proliferation and chemotherapeutic sensitivity via targeting Wee1 in colorectal cancer

Background

Numerous reports on microRNAs have illustrated their role in tumor growth and metastasis. Recently, a new prognostic factor, miR‐125b‐2‐3p, has been identified for predicting chemotherapeutic sensitivity in advanced colorectal cancer (CRC). However, the specific mechanisms and biological functions of miR‐125b‐2‐3p in advanced CRC under chemotherapy have yet to be elucidated.

Methods

MiR‐125b‐2‐3p expression was detected by real‐time PCR (RT‐PCR) in CRC tissues. The effects of miR‐125b‐2‐3p on the growth, metastasis, and drug sensitivity of CRC cells were tested in vitro and in vivo. Based on multiple databases, the upstream competitive endogenous RNAs (ceRNAs) and the downstream genes for miR‐125b‐2‐3p were predicted by bioinformatic analysis, followed by the experiments including luciferase reporter assays, western blot assays, and so on.

Results

MiR‐125b‐2‐3p was significantly lowly expressed in the tissues and cell lines of CRC. Higher expression of miR‐125b‐2‐3p was associated with relatively lower proliferation rates and fewer metastases. Moreover, overexpressed miR‐125b‐2‐3p remarkably improved chemotherapeutic sensitivity of CRC in vivo and in vitro. Mechanistically, miR‐125b‐2‐3p was absorbed by long noncoding RNA (lncRNA) XIST regulating WEE1 G2 checkpoint kinase (WEE1) expression. The upregulation of miR‐125b‐2‐3p inhibited the proliferation and epithelial‐mesenchymal transition (EMT) of CRC induced by lncRNA XIST.

Conclusions

Lower miR‐125b‐2‐3p expression resulted in lower sensitivity of CRC to chemotherapy and was correlated with poorer survival of CRC patients. LncRNA XIST promoted CRC metastasis acting as a ceRNA for miR‐125b‐2‐3p to mediate WEE1 expression. LncRNA XIST‐miR‐125b‐2‐3p‐WEE1 axis not only regulated CRC growth and metastasis but also contributed to chemotherapeutic resistance to CRC.

FOXK1 plays an oncogenic role in the progression of hilar cholangiocarcinoma

Hilar cholangiocarcinoma (HC) has a poor outcome in terms of survival. Forkhead box K1 (FOXK1) dysregulation is critical in solid tumors, which serves a pivotal role in the biological characteristics, such as invasion and migration, but its expression and functions in HC are unclear. The present study investigated the clinical significance and biological functions of FOXK1 in HC. Tumor microarrays and immunohistochemistry were used to evaluate FOXK1 in HC and its expression was modulated to determine its effects on chemoresistance and tumorigenesis. FOXK1 was highly expressed in HC and cell lines, which was associated with tumor invasion, regional lymph node metastasis, tumor recurrence and poor prognosis. Silencing FOXK1 in HC cells inhibited invasion and migration, upregulated E-cadherin, and downregulated vimentin, matrix metallopeptidase 9 and Twist in HC cells. Sensitivity to 5-fluorouracil and cisplatin was increased, and glutathione S-transferase π, multidrug resistance mutation 1 and P-glycoprotein expression levels were downregulated in RBE cells in vitro following FOXK1 knockdown. These results indicated that FOXK1 plays an oncogenic role in HC progression and can serve as a novel therapeutic target for HC.

XRCC4, which is inhibited by PFDA, regulates DNA damage repair and cell chemosensitivity

The mechanism of environmental pollution promoting gastric cancer incidence and difficulty of treatment is not fully understood. In the present article, perfluorodecanoic acid (PFDA), a common persistent environmental pollutant, was used to treat the gastric cell lines and mice to test its genotoxicity. The γ-H2AX immunoblot and plasmid fragment PCR results showed that PFDA had a promotion effect on the DNA double-strand breaks (DSBs) in human and mouse cells. Subsequent results showed that PFDA significantly altered the sensitivity of cells to chemotherapy. Microarray data showed that the expressions of some important DNA repair genes were changed. Further investigation discovered that PFDA inhibition of DNA repair was mediated by X-ray repair cross complementing 4 (XRCC4). The cells deficient in XRCC4 generally exhibited reduced proliferation and premature aging in culture; however, our results indicated that PFDA induced p53 inhibition rescued cells from the apoptosis that was triggered by nonhomologous end-joining (NHEJ) inactivation, and overexpression of p53 expression in PFDA-treated cells enhanced their apoptosis. Finally, T-cell specific factor 4 was suggested by the results as an upstream regulator of XRCC4. This article revealed for the first time that perfluorinated chemicals affect chemotherapeutic sensitivity and the NHEJ pathway, and p53 reduction rescues cells from death.

Huaier Augmented the Chemotherapeutic Sensitivity of Oxaliplatin via Downregulation of YAP in Hepatocellular Carcinoma

For unresectable Hepatocellular carcinoma (HCC), chemotherapy is still an important treatment strategy. Oxaliplatin (Oxa) is an effective treatment of HCC after sorafenib treatment failure. However, the intrinsic or acquired resistance of Oxa affected the chemotherapeutic sensitivity. By analyzing the data of GEO Database, we found that Oxa aberrantly increased the expression of Cysteine-rich61 (Cyr61) in HCC cell lines. Subsequently, in Bel-7404 and SMMC-7721 cells after treated with Oxa, it was verified that the expression of Cyr61 and Yes-associated protein (YAP) was increased. Moreover, we found that blockade of YAP promoted Oxa-induced cell apoptosis for the first time. Meanwhile, our previous study demonstrated that Huaier (HE) inhibited the expression of YAP. Further study found that combination treatment of Oxa and HE had a significantly synergistic anti-cancer effect and significantly inhibited the expression of YAP and apoptosis related proteins. Taken together, we have observed that overexpression of YAP significantly reduced the chemotherapeutic sensitivity of Oxa in HCC for the first time. Combination treatment of Oxa and HE solved this problem.

Silencing Livin improved the sensitivity of colon cancer cells to 5-fluorouracil by regulating crosstalk between apoptosis and autophagy

Colorectal cancer (CRC) is the third most common cause of cancer-associated mortality worldwide. Currently, 5-fluorouracil (5-FU) remains a widely used chemotherapeutic drug in the treatment of CRC; however, 5-FU resistance during treatment has become a common problem. Livin, a member of the inhibitor of apoptosis protein family, is considered to be associated with tumor resistance to chemotherapy. In the present study, Livin-silenced cells were generated by introducing a lentivirus into HCT116 and SW620 colon cancer cell lines. Acridine orange/ethidium bromide staining was used as an indicator of cell death. Western blot analysis was performed to detect protein expression levels, and transmission electron microscopy was used to assess autophagy. The half-maximal inhibitory concentration of 5-FU in colon cancer cells was evaluated using a Cell Counting Kit-8 assay. The results of the present study confirmed that silencing Livin significantly enhanced colon cancer cell death in the presence of 5-FU, increased expression levels of various apoptosis- and autophagy-associated proteins and augmented chemotherapeutic sensitivity to 5-FU. Furthermore, the present study demonstrated that this effect may be reversed when autophagy or apoptosis was inhibited, indicating that apoptosis and autophagy were involved in this process. The protein kinase B signaling pathway and B-cell lymphoma-2 expression levels significantly decreased following Livin knockdown, suggesting they may contribute to the regulation of apoptosis and autophagy crosstalk, which caused the Livin knockdown-induced cell death observed.

CISD2 enhances the chemosensitivity of gastric cancer through the enhancement of 5-FU-induced apoptosis and the inhibition of autophagy by AKT/mTOR pathway

Gastric cancer (GC) is a prevalent upper gastrointestinal tumor characterized by high morbidity and mortality due to imperfect screening systems and the rapid development of resistance to 5‐fluorouracil (5‐FU). CDGSH iron sulfur domain 2 (CISD2) has been recently regarded as a candidate oncogene in several types of tumors. It is, therefore, necessary to investigate its biological function and clinical significance in gastric cancer. In this study, the down‐regulated expression level of CISD2 in GC compared with adjacent normal tissues was evaluated by quantitative RT‐PCR and Western blotting. An immunohistochemical analysis indicated that CISD2 expression in GC was significantly correlated with age (P = 0.002), Lauren's classification (P = 0.001), and differentiation (P = 0.049). Two cell lines, MKN1 and BGC823, were used to analyze the role of CISD2 in gastric carcinogenesis and response to 5‐FU through CCK‐8 assays, the RT‐CES system, Transwell assays, flow cytometry, and confocal fluorescence microscopy. The overexpression of CISD2 resulted in reduced cellular growth and proliferation, inhibition of metastatic ability, and increased apoptosis. 5‐FU treatment increased endogenous as well as exogenous overexpression of CISD2 in GC cells. Further investigation revealed that CISD2 enhanced sensitivity to 5‐FU via an increase in apoptosis and inhibition of protective autophagy through the activation of the AKT/mTOR pathway. In conclusion, CISD2 is down‐regulated in gastric cancer, and its effects on the inhibition of cellular proliferation, metastatic ability, and increased chemotherapy sensitivity are mediated by antagonism to 5‐FU‐induced autophagy through the AKT/mTOR pathway.

Photothermal Effect Enhanced Cascade-Targeting Strategy for Improved Pancreatic Cancer Therapy by Gold Nanoshell@Mesoporous Silica Nanorod

Pancreatic cancer, one of the leading causes of cancer-related mortality, is characterized by desmoplasia and hypovascular cancerous tissue, with a 5 year survival rate of <8%. To overcome the severe resistance of pancreatic cancer to conventional therapies, we synthesized gold nanoshell-coated rod-like mesoporous silica (GNRS) nanoparticles which integrated cascade tumor targeting (mediated by photothermal effect and molecular receptor binding) and photothermal treatment-enhanced gemcitabine chemotherapy, under mild near-infrared laser irradiation condition. GNRS significantly improved gemcitabine penetration and accumulation in tumor tissues, thus destroying the dense stroma barrier of pancreatic cancer and reinforcing chemosensitivity in mice. Our current findings strongly support the notion that further development of this integrated plasmonic photothermal strategy may represent a promising translational nanoformulation for effective treatment of pancreatic cancer with integral cascade tumor targeting strategy and enhanced drug delivery efficacy.

JNK pathway inhibition enhances chemotherapeutic sensitivity to Adriamycin in nasopharyngeal carcinoma cells

The role of c-Jun N-terminal kinases (JNKs) in the pathogenesis of cancer is well-known due to their involvement in carcinogenesis. Although previous studies have discussed different functions of JNKs depending on cell type, the present study aimed to investigate the function of JNKs in nasopharyngeal carcinoma (NPC) cells, as well as their involvement in chemotherapy sensitivity to Adriamycin. The present results showed that Adriamycin administration reduced cell viability and led to elevated expressions of c-Jun, phosphorylated JNK and phosphorylated c-Jun, indicating an activated JNK pathway. Notably, JNK inhibition by SP600125 also reduced cell growth. Thus, Adriamycin treatment combined with SP600125 was more effective on cell growth inhibition than each agent alone. The apoptosis analysis confirmed the reduction in cell growth. Therefore, these data provide evidence that the JNK pathway activity is negatively associated with cell viability, and its decline could sensitize NPC cells to Adriamycin.

MicroRNA-146a affects the chemotherapeutic sensitivity and prognosis of advanced gastric cancer through the regulation of LIN52

The present study aimed to evaluate the correlation between the expression of microRNA-146a (miR-146a) and its target gene, LIN52, in advanced gastric cancer, and determine their potential effects on chemotherapeutic sensitivity and prognosis. Total RNA was extracted from 93 tissue samples of advanced gastric cancer and corresponding adjacent non-tumor tissues to quantify the relative expression levels of miR-146a using reverse transcription-quantitative polymerase chain reaction analysis. The expression of LIN52 was detected in tumors and normal tissues using immunohistochemical analysis. Correlation analysis was performed to assess the correlation between the expression of miR-146a and LIN52 and clinicopathological parameters of gastric cancer, including clinical diagnostic specificity, clinical tumor-necrosis-metastasis staging, lymph node metastasis, differentiation grade, chemotherapeutic sensitivity and prognosis. The expression of miR-146a in advanced gastric cancer tissues was lower, compared with that in the adjacent non-tumor tissues, and was negatively correlated with lymph node metastasis (P<0.05). Gastric cancer tissues with a low expression level of miR146a exhibited an increased expression level of LIN52 (P<0.05). Receiver operating characteristic curve regression analysis showed that miR-146a had 98% sensitivity in distinguishing gastric cancer tissues and adjacent non-tumor tissues. A high expression of miR-146a in gastric cancer was associated with improved treatment efficacy in patients. The chemotherapeutic sensitivity of patients with tumors expressing high levels of miR-146a was significantly higher, compared with that of patients with tumors expressing low levels of miR-146a (P<0.05). The expression of miR-146a was low in advanced gastric cancer tissues. As a tumor suppressor gene in advanced gastric cancer, miR-146a had a significant negative correlation with LIN52. High expression levels of miR-146a in advanced gastric cancer tissue may be associated with improved treatment efficacy of chemotherapy, suggesting that miR-146a may be a molecular marker for the diagnosis, prediction of treatment efficacy and prognosis of advanced gastric cancer.

Effects of siRNA Livin on EJ human bladder cancer cells treated with mitomycin-C

The aim of this study was to observe the inhibitory and therapeutic effects of small interfering RNA (siRNA) targeting Livin in EJ human bladder cancer cells. Specific siRNA targeting Livin was synthesized and transfected into EJ human bladder cancer cells treated or not treated with mitomycin-C (MMC). Livin mRNA and protein, as well as proliferation and apoptosis of EJ cells was examined with reverse transcription-polymerase chain reaction, western blotting, Cell Counting Kit-8 assay and flow cytometry, respectively. The results indicated that the expression of Livin mRNA and protein in EJ cells was significantly decreased by siRNA Livin. The proliferation of EJ cells was significantly inhibited by treatment with MMC and transfection of siRNA Livin. The inhibition of cell proliferation by treatment with MMC was further enhanced by transfection of siRNA Livin. The apoptotic rate of cells transfected with siRNA Livin and treated with MMC was significantly higher than those cells receiving a single transfection of siRNA Livin and single treatment of MMC. In conclusion, the present study demonstrates that transfection of siRNA Livin induces growth suppression and apoptosis in EJ human bladder cancer cells, and increases the chemotherapeutic sensitivity of cells to MMC.

MicroRNA-101-3p suppresses cell proliferation, invasion and enhances chemotherapeutic sensitivity in salivary gland adenoid cystic carcinoma by targeting Pim-1

MicroRNAs (miRNAs) play critical roles in carcinogenesis and tumor progression. Recent research has revealed miR-101-3p as an important regulator in several cancers. Nevertheless, its function in salivary gland Adenoid cystic carcinoma (ACC), a relatively rare malignance with poor long-term survival rate arisen in head and neck region, remain unknown. In this study, down-regulated miR-101-3p expression was detected in ACC tissues and ACC cell lines with high potential for metastasis. Ectopic expression of miR-101-3p significantly repressed the invasion, proliferation, colony formation, and formation of nude mice xenografts and induced potent apoptosis in ACC cell lines. The provirus integration site for Moloney murine leukemia virus 1 (Pim-1) oncogene was subsequently confirmed as a direct target gene of miR-101-3p in ACC. Functional restoration assays revealed that miR-101-3p inhibits cell growth and invasion by directly decreasing Pim-1 expression. Protein levels of Survivin, Cyclin D1 and β-catenin were also down-regulated by miR-101-3p. miR-101-3p enhanced the sensitivity of cisplatin in ACC cell lines. Taken together, our results demonstrate that the novel miR-101-3p/Pim-1 axis provides excellent insights into the carcinogenesis and tumor progression of ACC and may be a promising therapeutic target for this type of cancer.

MicroRNA-181a enhances the chemotherapeutic sensitivity of chronic myeloid leukemia to imatinib

MicroRNA-181 (miR-181) has been recently demonstrated to participate in the differentiation and development of immune cells, including natural killer cells and B and T lymphocytes, and myeloid linages, including erythroid and megakaryocytic cells. The aberrant expression of miR-181, particularly low expression levels, has been observed in a number of leukemia types, including B-cell chronic lymphocytic leukemia and cytogenetically abnormal acute myeloid leukemia. However, the expression and function of miR-181 in chronic myeloid leukemia (CML) remains unknown. In the present study, the aberrant expression of miR-181a was analyzed in a patient with CML and in the CML K562 cell line. In addition, the function and potential mechanisms of miR-181a in K562 cells with regard to their chemotherapeutic sensitivity to imatinib were investigated. The expression levels of miR-181a were significantly reduced in the patient with CML and in the CML K562 cell line. Furthermore, the overexpression of miR-181a in the K562 cells enhanced the chemotherapeutic sensitivity of these cells to imatinib. The potential mechanism mediating these effects may be associated with the capacity of miR-181a to inhibit cell growth and/or to induce cells apoptosis and differentiation in K562 cells. The results of the present study suggested that miR-181a may be a target for the treatment of CML and a useful indicator of the therapeutic sensitivity of CML to imatinib.

MicroRNA biogenesis and cellular proliferation

Given the fundamental roles of microRNAs (miRNAs) in physiological, developmental, and pathologic processes, we hypothesized that genes involved in miRNA biogenesis contribute to human complex traits. For 13 such genes, we evaluated the relationship between transcription and 2 classes of complex traits, namely cellular growth and sensitivity to various chemotherapeutic agents in a set of lymphoblastoid cell lines. We found a highly significant correlation between argonaute RNA-induced silencing complex catalytic component 2 (AGO2) expression and cellular growth rate (Bonferroni-adjusted P < 0.05), and report additional miRNA biogenesis genes with suggestive associations with either cellular growth rate or chemotherapeutic sensitivity. AGO2 expression was found to be correlated with multiple drug sensitivity phenotypes. Furthermore, small interfering RNA knockdown of AGO2 resulted in cellular growth inhibition in an ovarian cancer cell line (OVCAR-3), supporting the role of this miRNA biogenesis gene in cell proliferation in cancer cells. Expression quantitative trait loci mapping indicated that genetic variation (in the form of both single-nucleotide polymorphisms and copy number variations) that may regulate the expression of AGO2 can have downstream effects on cellular growth-dependent complex phenotypes.

Role of RNA-interference-induced zinc finger protein 139 suppression in gastric cancer cell sensitivity to chemotherapeutic agents

Zinc finger proteins (ZNFs) are a class of proteins widely distributed in the human genome, which have been found to play a role in the regulation of gene transcription and the occurrence and development of gastric cancer (GC). ZNF139 was found to be associated with GC in our previous experiments. The present study aimed to analyse the differences in ZNF139 protein expression in SGC7901 GC cells and in situ grafted GC tumors in nude mice prior to and following RNA interference inhibition, and to investigate the mechanisms underlying ZNF139 involvement in the occurrence, development and chemosensitivity of GC. A ZNF139-targeted small interfering (si)RNA plasmid was constructed and transfected into the cancer cells and in situ grafted tumors. The MTT assay was used to investigate the alterations in chemosensitivity prior to and following transfection of siRNA-ZNF139. The two-dimensional difference gel electrophoresis and liquid chromatography-mass spectrometry techniques were used to identify the different protein points prior to and following siRNA-ZNF139 transfection. Western blot analysis was performed to confirm the identified proteins. In the siRNA-ZNF139 group, the growth of the cancer cells and in situ grafted tumors significantly decreased. However, the post-interference chemosensitivity to 5-fluorouracil, cisplatin and mitomycin C significantly increased. In the in vivo and in vitro experiments, the expression of pyridoxal kinase (PDXK) was upregulated, whereas the expression levels of annexin A2 (ANXA2) and fascin were downregulated following transfection. Western blot analysis confirmed the results for PDXK, ANXA2 and fascin by proteomics. Therefore, ZNF139 may participate in the occurrence, development and chemosensitivity of GC by promoting the expression of ANXA2 and fascin, while inhibiting the expression of PDXK.

Ascites-derived pancreatic ductal adenocarcinoma primary cell cultures as a platform for personalised medicine

BACKGROUND

Challenges in developing drugs for pancreatic ductal adenocarcinoma (PDAC) include obtaining metastatic cancer tissue for research and validating biomarkers predicative for personalised therapeutic decisions. We have recently developed a novel therapeutic model for PDAC to address these challenges based on the isolation of viable PDAC cells derived from ascites fluid.

METHODS

Ascites fluid was obtained from PDAC patients undergoing palliative paracentesis. Ascites-derived PDAC primary cells were isolated, cultured and characterised in ovo and in vitro.

RESULTS

We successfully established ascites-derived primary cell cultures within 2-7 days from 92% (93 out of 101) of the ascites fluid samples obtained (from 36 different patients). Homogeneous epithelial PDAC-enriched cell cultures were identified and characterised. We observed a wide range in doubling times and migration properties among the different patient-derived cell cultures. The diverse nature of each individual patient's cell cultures was further demonstrated by differences in therapeutic susceptibility and resistance. The tumorigenicity and invasiveness of the cells were demonstrated in vivo using chicken chorioallantoic membrane grafts.

CONCLUSIONS

We have developed a unique ascites-derived PDAC primary cell culture model. This model has the potential to study signalling pathways in PDAC progression and to evaluate targeted therapies for the individual patient expeditiously, thereby supporting personalised treatment decisions.