Inhibition of cyclin D1 enhances sensitivity to radiotherapy and reverses epithelial to mesenchymal transition for esophageal cancer cells

A narrative review of multiple mechanisms of progranulin in cancer: a potential target for anti-cancer therapy

Progranulin (PGRN) is an autocrine growth factor and has important effects on regulation of cell growth, motility, tissue repair and embryonic development. Recent years, several researches found the expression of PGRN was at higher levels in a number of cancer cells and its high levels are associated with poor outcome of patients. More and more studies investigated the role of PGRN in cancer and found PGRN exerted various biological functions in cancer cells, such as promoting proliferation, inhibiting apoptosis, inducing migration and invasion of cells, accelerating angiogenesis and enhancing the effectiveness of chemoresistance and radiation. Now the effects of PGRN have been demonstrated in several cancers, including breast cancer, lung cancer, and bladder cancer. In addition, several signaling pathways and molecules are involved in the effects of PGRN on cancer cells, including Akt, mitogen-activated protein kinase (MAPK), vascular endothelial growth factor (VEGF) and cyclin D1. Therefore, PGRN is probably a significant diagnostic and prognostic biomarker for cancer and may be a potential target for anti-cancer therapy. Here, we reviewed the advancing field of PGRN in cancer as well as several signaling pathways activated by PGRN and confirmed PGRN is a key role in cancer. Moreover, future studies are still necessary to elucidate the biological functions and signaling pathways of PGRN in cancer.

Radiation-induced DNA damage and altered expression of p21, cyclin D1 and Mre11 genes in human fibroblast cell lines with different radiosensitivity

PURPOSE

Radiotherapy plays a pivotal role in the treatment of cancer. One of the main challenges in this treatment modality is radiation-induced complications in some patients affected by high radiosensitivity (RS). The differences in RS are determined mainly by genetic factors. Therefore, identifying the genes and mechanisms that affect RS in different cells is essential for evaluating radiotherapy outcomes. In the present study, the ability to repair DNA double-stranded breaks (DSB) is evaluated, followed by examining the expression levels of CDKN1A (p21), cyclinD1, and Mre11 genes in human fibroblasts with different RSs.

MATERIALS & METHODS

Cellular RS was measured by survival fraction at 2 Gy (SF2). The γ-H2AX assay was used for assessing DNA repair capacity. Eventually, gene expression levels from each cell line 4 and 24 h after irradiation (at 2, 4, and 8 Gy) were measured by real-time PCR.

RESULTS

The SF2 values for the cell lines ranged from 0.286 to 0.641, and RS differences of fibroblast cells were identified. Among the studied genes, the expression of Mre11 was the most important. Analysis of the real-time PCR data showed that changes in Mre11 gene expression (4 h after 8 Gy irradiation) were directly correlated with the RS (R² = 0.905). The difference in the expression of the p21 gene (4 h after 4 Gy irradiation) was also promising. Finally, the flow cytometry analysis showed that the radioresistant cell lines quickly repaired DBS damages. However, the repair process was slow in the radiosensitive cell line, and the residual damage is significantly higher than other cell lines (P < 0.01).

CONCLUSIONS

This study indicates that changes in the expression of p21 and Mre11 genes play an important role in cell response to radiation and thus these genes can be introduced as biomarkers to predict RS in normal cell lines.

The mechanisms and reversal strategies of tumor radioresistance in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is one of most lethal malignancies with high aggressive potential in the world. Radiotherapy is used as one curative treatment modality for ESCC patients. Due to radioresistance, the 5-year survival rates of patients after radiotherapy is less than 20%. Tumor radioresistance is very complex and heterogeneous. Cancer-associated fibroblasts (CAFs), as one major component of tumor microenvironment (TME), play critical roles in regulating tumor radioresponse through multiple mechanisms and are increasingly considered as important anti-cancer targets. Cancer stemness, which renders cancer cells to be extremely resistant to conventional therapies, is involved in ESCC radioresistance due to the activation of Wnt/β-catenin, Notch, Hedgehog and Hippo (HH) pathways, or the induction of epithelial-mesenchymal transition (EMT), hypoxia and autophagy. Non-protein-coding RNAs (ncRNAs), which account for more than 90% of the genome, are involved in esophageal cancer initiation and progression through regulating the activation or inactivation of downstream signaling pathways and the expressions of target genes. Herein, we mainly reviewed the role of CAFs, cancer stemness, non-coding RNAs as well as others in the development of radioresistance and clarify the involved mechanisms. Furthermore, we summarized the potential strategies which were reported to reverse radioresistance in ESCC. Together, this review gives a systematic coverage of radioresistance mechanisms and reversal strategies and contributes to better understanding of tumor radioresistance for the exploitation of novel intervention strategies in ESCC.

The Role of Cyclin D1 and VEGF in Radiotherapy Response of Advance Stage Undifferentiated Nasopharyngeal Carcinoma

Nasopharyngeal carcinoma has a high incidence and mortality rate in Southeast Asia and Indonesia. Radioresistance is a major obstacle to successful treatment of nasopharyngeal carcinoma. DNA repair in the cell cycle and angiogenesis factors affects the response of tumor cells to radiotherapy. Cyclin D1 that functions in the cell cycle process and VEGF as an angiogenesis factor are considered to play a role in the occurrence of radioresistance. The objective of this study is to find the association between immunoexpression of Cyclin D1 and VEGF with radiotherapy response in undifferentiated nasopharyngeal carcinoma. This study used a retrospective case control analysis design, secondary data from medical records of patients diagnosed as undifferentiated nasopharyngeal carcinoma who received complete radiotherapy at the Radiation Oncology Department  Dr Hasan Sadikin Bandung were taken. There were 44 samples divided into radiosensitive (22 samples) and radioresistant (22 samples) groups. Immunohistochemical examination of Cyclin D1 and VEGF was performed on paraffin blocks of patients' biopsy. Data analysis using Chi-Square test (p ≤0.05) , OR 95% CI. Cyclin D1 expressed strongly in 86.4% of the radioresistant group and 59.1% in the radiosensitive group (p<0.05) and the OR 4,385 (0.993-19.356), VEGF was strongly expressed in 77.3% of the radioresistant group and 54.5% in the radiosensitive group (p>0.05). As conclusion, there were significant association between Cyclin D1 with radiotherapy respons in undifferentiated nasopharyngeal carcinoma. The stronger immunoexpression of Cyclin D1, the higher likelihood of radioresistancy. VEGF immunoexpression showed no significant association with radiotherapy response.

STAT3, the Challenge for Chemotherapeutic and Radiotherapeutic Efficacy

Chemoradiotherapy is one of the most effective and extensively used strategies for cancer treatment. Signal transducer and activator of transcription 3 (STAT3) regulates vital biological processes, such as cell proliferation and cell growth. It is constitutively activated in various cancers and limits the application of chemoradiotherapy. Accumulating evidence suggests that STAT3 regulates resistance to chemotherapy and radiotherapy and thereby impairs therapeutic efficacy by mediating its feedback loop and several target genes. The alternative splicing product STAT3β is often identified as a dominant-negative regulator, but it enhances sensitivity to chemotherapy and offers a new and challenging approach to reverse therapeutic resistance. We focus here on exploring the role of STAT3 in resistance to receptor tyrosine kinase (RTK) inhibitors and radiotherapy, outlining the potential of targeting STAT3 to overcome chemo(radio)resistance for improving clinical outcomes, and evaluating the importance of STAT3β as a potential therapeutic approach to overcomes chemo(radio)resistance. In this review, we discuss some new insights into the effect of STAT3 and its subtype STAT3β on chemoradiotherapy sensitivity, and we explore how these insights influence clinical treatment and drug development for cancer.

Downregulation of TMPRSS4 Enhances Triple-Negative Breast Cancer Cell Radiosensitivity Through Cell Cycle and Cell Apoptosis Process Impairment

Background:

Radioresistance remains a challenge for cancer radiotherapy. The present study aims to investigate the role of TMPRSS4 in triple negative breast cancer (TNBC) cell radiosensitivity.

Materials and Methods:

After transfection of MDA-MD-468 triple negative breast cancer cells line by using the lentivirus vector, the effect of TMPRSS4 down-regulation on TNBC radiosensitivity was evaluated by using cloning assay and CCK-8 assay. The CCK-8 assay was also used for performing cell proliferation analysis. Western blot was carried out to detect the expression of certain proteins related to cell cycle pathways (cyclin D1), cell apoptosis pathways (Bax, Bcl2, and Caspase3), DNA damage and DNA damage repair (TRF2, Ku80 , ˠH2AX) . The cell cycle and cell apoptosis were also investigated using flow cytometer analysis.

Results:

TMPRSS4 expression was down-regulated in MDA-MB-468 cells which enhanced MDA-MB-468 cells radiosensitivity. TMPRSS4 silencing also improved IR induced cell proliferation ability reduction and promoted cell arrested at G2/M phase mediated by 6 Gy IR associated with cyclin D1 expression inhibition. Moreover, TMPRSS4 inhibition enhanced TNBC apoptosis induced by 6 Gy IR following by over-expression of (Bax, Caspase3) and down-regulation of Bcl2 as the pro-apoptotic and anti-apoptotic proteins, respectively. Otherwise, TMPRSS4 down-regulation increases DNA damage induced by 6 Gy IR and delays DNA damage repair respectively illustrated by downregulation of TRF2 and permanent increase of Ku80 and ˠH2AX expression at 1 h and 10 h post-IR.

Conclusion:

Down-regulation of TMPRSS4 increases triple negative breast cancer cell radiosensitivity and the use of TMPRSS4 inhibitor can be encouraged for improving radiotherapy effectiveness in TNBC radioresistant patients.

Cyclin D1 is Associated with Radiosensitivity of Triple-Negative Breast Cancer Cells to Proton Beam Irradiation

Proton therapy offers a distinct physical advantage over conventional X-ray therapy, but its biological advantages remain understudied. In this study, we aimed to identify genetic factors that contribute to proton sensitivity in breast cancer (BC). Therefore, we screened relative biological effectiveness (RBE) of 230 MeV protons, compared to 6 MV X-rays, in ten human BC cell lines, including five triple-negative breast cancer (TNBC) cell lines. Clonogenic survival assays revealed a wide range of proton RBE across the BC cell lines, with one out of ten BC cell lines having an RBE significantly different from the traditional generic RBE of 1.1. An abundance of cyclin D1 was associated with proton RBE. Downregulation of RB1 by siRNA or a CDK4/6 inhibitor increased proton sensitivity but not proton RBE. Instead, the depletion of cyclin D1 increased proton RBE in two TNBC cell lines, including MDA-MB-231 and Hs578T cells. Conversely, overexpression of cyclin D1 decreased the proton RBE in cyclin D1-deficient BT-549 cells. The depletion of cyclin D1 impaired proton-induced RAD51 foci formation in MDA-MB-231 cells. Taken together, this study provides important clues about the cyclin D1-CDK4-RB1 pathway as a potential target for proton beam therapy in TNBC.

Brucea javanica oil emulsion improves the effect of radiotherapy on esophageal cancer cells by inhibiting cyclin D1-CDK4/6 axis

BACKGROUND

Esophageal cancer is one of the most common cancers around the world, and it has high incidence and mortality rates. The conventional therapy for esophageal cancer is radiotherapy, although its effect is highly limited by the resistance of esophageal cancer cells. Thus, strong radiosensitizers can be very crucial during radiotherapy against esophageal cancer. Brucea javanica oil emulsion (BJOE) is a widely used drug against various cancers, such as liver, colon, and ovarian cancer. However, its anti-cancer effect and mechanism and the use of BJOE as a radiosensitizer have not been explored in esophageal cancer.

AIM

To evaluate the anti-cancer effect and mechanism of BJOE and explore the potential use of BJOE as a radiosensitizer during radiotherapy.

METHODS

The inhibitory effect of BJOE and its enhancement function with radiation on cell viability were examined with the calculated half-maximal effective concentration and half-maximal lethal concentration. The influence of BJOE on cell migration and invasion were measured with EC109 and JAR cells by wound-healing and transwell assay. Clonogenesis and apoptotic rate, which was measured by Hoechst staining, were investigated to confirm its enhancement function with radiation. To investigate the molecular pathway underlying the effect of BJOE, the expressions of several apoptosis- and cycle-related proteins was detected by western blotting.

RESULTS

Our results demonstrated that BJOE inhibited the growth of esophageal cancer cell lines more than normal cell lines, and it markedly reduced migration and invasion in esophageal cancer cells (EC109 and JAR). Moreover, it promoted cell apoptosis and enhanced the effect of radiotherapy against esophageal cancerous cells. In the viability test, the values of half-maximal effective concentration and half-maximal lethal concentration were reduced. Compared to the control, only around 1/5 colonies formed when using BJOE and radiation together in the clonogenic assay. The apoptotic rate in EC109 was obviously promoted when BJOE was added during radiotherapy. Our study suggests that the expression of the apoptosis-proteins Bax and p21 were increased, while the expression of Bcl-2 was stable. Further detection of downstream proteins revealed that the expression of cyclin D1 and cyclin-dependent kinase 4/6 were significantly decreased.

CONCLUSION

BJOE has a strong anti-cancer effect on esophageal cancer and can be used as a radiosensitizer to promote apoptosis in cancerous esophageal cells via the cyclin D1-cyclin-dependent kinase 4/6 axis.

Genistein and AG1024 synergistically increase the radiosensitivity of prostate cancer cells

Radiosensitivity of prostate cancer (PCa) cells promotes the curative treatment for PCa. The present study was designed to investigate the synergistic effect of genistein and AG1024 on the radiosensitivity of PCa cells. The optimal X-irradiation dose (4 Gy) and genistein concentration (30 µM) were selected by using the CCK-8 assay. Before X-irradiation (4 Gy), PC3 and DU145 cells were treated with genistein (30 µM), AG1024 (10 µM) and their combination. All treatments significantly reduced cell proliferation and enhanced cell apoptosis. Using flow cytometric analysis, we found that genistein arrested the cell cycle at S phase and AG1024 arrested the cell cycle at G2/M phase. Genistein treatment suppressed the homologous recombination (HRR) and the non-homologous end joining (NHEJ) pathways by inhibiting the expression of Rad51 and Ku70, and AG1024 treatment only inhibited the NHEJ pathway via the inactivation of Ku70 as detected by western blot analysis. Moreover, the combination treatment with genistein and AG1024 more effectively radiosensitized PCa cells than single treatments by suppressing cell proliferation, enhancing cell apoptosis and inactivating the HRR and NHEJ pathways. In vivo experiments demonstrated that animals receiving the combination treatment with genistein and AG1024 displayed obviously decreased tumor volume compared with animals treated with single treatment with either genistein or AG1024. We conclude that the combination of genistein (30 µM) and AG1024 (10 µM) exhibited a synergistic effect on the radiosensitivity of PCa cells by suppressing the HRR and NHEJ pathways.

The enhanced effect of tetrahydrocurcumin on radiosensitivity of glioma cells

Objectives

To evaluate the effects of tetrahydrocurcumin (THC) on the radiosensitivity of glioma cells and the possible molecular mechanism.

Methods

MTT assay, colony forming and wound healing assays were performed to detect the proliferation, radiosensitivity and migration of cells with various treatments. Cell apoptosis, cell cycle and GHS level were determined for exploring potent sensitization mechanism of THC. Meanwhile, protein expressions of cyclin D1 and PCNA were also measured. Furthermore, both orthotopic C6 mouse models and C6 subcutaneously grafted mouse models were established to test the tumour inhibitory effects of combined treatment in vivo.

Key findings

Cells treated with combined THC and radiation demonstrated lower cell viability and higher apoptosis rate as compared to radiation group. Moreover, the intracellular GSH was also decreased in the THC co-treated C6 cells. More importantly, combinatorial treatment group significantly induced G0/G1 cell cycle arrest and a decrease in the S phase cell through the down-regulation of cyclin D1 and PCNA. The in-vivo therapeutic efficacy assay indicated that the growth of tumour was greatly inhibited in combinatorial group.

Conclusions

Tetrahydrocurcumin can synergistically enhance the radiosensitivity of glioma cells by inhibiting the expressions of cyclin D1 and PCNA.

Profiling and bioinformatics analyses reveal differential circular RNA expression in radioresistant esophageal cancer cells

Background

Acquired radioresistance during radiotherapy is considered as the most important reason for local tumor recurrence or treatment failure. Circular RNAs (circRNAs) have recently been identified as microRNA sponges and involve in various biological processes. The purpose of this study is to investigate the role of circRNAs in the radioresistance of esophageal cancer.

Methods

Total RNA was isolated from human parental cell line KYSE-150 and self-established radioresistant esophageal cancer cell line KYSE-150R, and hybridized to Arraystar Human circRNA Array. Quantitative real-time PCR was used to confirm the circRNA expression profiles obtained from the microarray data. Bioinformatic tools including gene ontology (GO) analysis, KEGG pathway analysis and network analysis were done for further assessment.

Results

Among the detected candidate 3752 circRNA genes, significant upregulation of 57 circRNAs and downregulation of 17 circRNAs in human radioresistant esophageal cancer cell line KYSE-150R were observed compared with the parental cell line KYSE-150 (fold change ≥2.0 and P < 0.05). There were 9 out of these candidate circRNAs were validated by real-time PCR. GO analysis revealed that numerous target genes, including most microRNAs were involved in the biological processes. There were more than 400 target genes enrichment on Wnt signaling pathway. CircRNA_001059 and circRNA_000167 were the two largest nodes in circRNA/microRNA co-expression network.

Conclusions

Our study revealed a comprehensive expression and functional profile of differentially expressed circRNAs in radioresistant esophageal cancer cells, indicating possible involvement of these dysregulated circRNAs in the development of radiation resistance.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-016-0977-7) contains supplementary material, which is available to authorized users.

Mesenchymal Stromal Cells Epithelial Transition Induced by Renal Tubular Cells-Derived Extracellular Vesicles

Mesenchymal-epithelial interactions play an important role in renal tubular morphogenesis and in maintaining the structure of the kidney. The aim of this study was to investigate whether extracellular vesicles (EVs) produced by human renal proximal tubular epithelial cells (RPTECs) may induce mesenchymal-epithelial transition of bone marrow-derived mesenchymal stromal cells (MSCs). To test this hypothesis, we characterized the phenotype and the RNA content of EVs and we evaluated the in vitro uptake and activity of EVs on MSCs. MicroRNA (miRNA) analysis suggested the possible implication of the miR-200 family carried by EVs in the epithelial commitment of MSCs. Bone marrow-derived MSCs were incubated with EVs, or RPTEC-derived total conditioned medium, or conditioned medium depleted of EVs. As a positive control, MSCs were co-cultured in a transwell system with RPTECs. Epithelial commitment of MSCs was assessed by real time PCR and by immunofluorescence analysis of cellular expression of specific mesenchymal and epithelial markers. After one week of incubation with EVs and total conditioned medium, we observed mesenchymal-epithelial transition in MSCs. Stimulation with conditioned medium depleted of EVs did not induce any change in mesenchymal and epithelial gene expression. Since EVs were found to contain the miR-200 family, we transfected MSCs using synthetic miR-200 mimics. After one week of transfection, mesenchymal-epithelial transition was induced in MSCs. In conclusion, miR-200 carrying EVs released from RPTECs induce the epithelial commitment of MSCs that may contribute to their regenerative potential. Based on experiments of MSC transfection with miR-200 mimics, we suggested that the miR-200 family may be involved in mesenchymal-epithelial transition of MSCs.

The long non-coding RNA NEAT1 regulates epithelial to mesenchymal transition and radioresistance in through miR-204/ZEB1 axis in nasopharyngeal carcinoma

Long non-coding RNAs (lncRNAs) play a critical role in cancer progression, including in nasopharyngeal carcinoma (NPC). However, it is still poorly understood whether lncRNA regulates epithelial to mesenchymal transition (EMT) and radioresistance of NPC cells. We found that lncRNA NEAT1 was significantly upregulated in NPC cell lines and tissues. Knockdown of NEAT1 could sensitize NPC cells to radiation in vitro. Further investigation found that NEAT1 regulated radioresistance by modulating EMT phenotype. Furthermore, we found that there was reciprocal repression between NEAT1 and miR-204. ZEB1 was identified as a downstream target of miR-204 and NEAT1 upregulated ZEB1 expression by negatively regulating miR-204 expression. Taking together, we proposed that NEAT1 regulated EMT phenotype and radioresistance by modulating the miR-204/ZEB1 axis in NPC.