Radiosensitivity Of Esophageal Squamous Cell Carcinoma Cells Research Articles

Exosome-transported of circ_0081069 induces SPIN1 production by binding to miR-195-5p to inhibit radiosensitivity in esophageal squamous cell carcinoma.

Circ_0081069 plays a key role in tumor growth; however, its effect on radiosensitivity in esophageal squamous cell carcinoma (ESCC) remains unknown. The study is performed to reveal the association of circ_0081069 expression and radiosensitivity in ESCC and the underlying mechanism. Circ_0081069, miR-195-5p, and spindlin 1 (SPIN1) RNA expression were detected by quantitative real-time polymerase chain reaction. Protein expression was checked by Western blot analysis or immunohistochemistry assay. Cell viability, proliferation, cell apoptosis, migration, and invasion were investigated by cell counting kit-8, 5-Ethynyl-29-deoxyuridine, flow cytometry analysis, scratch test, and transwell assays, respectively. The sensitivity of ESCC cells to radiation was investigated by cell colony formation assay. The interactions among circ_0081069, miR-195-5p, and SPIN1 were identified by dual-luciferase reporter assay and RNA Immunoprecipitation assay. Xenograft mouse model assay was performed to determine the effect of circ_0007841 on radiosensitivity in vivo. Circ_0081069 and SPIN1 expression were upregulated, whereas miR-195-5p was downregulated in ESCC tissues, ESCC cells, and radiation-stimulated ESCC cells. Circ_0081069 silencing inhibited ESCC cell proliferation, invasion, and migration but improved cell apoptosis. In addition, circ_0081069 knockdown enhanced ESCC cell radiosensitivity in vitro and in vivo. Circ_0081069 bound to miR-195-5p and regulated radiosensitivity by binding to miR-195-5p in ESCC cells. Moreover, SPIN1, a target of miR-195-5p, rescued miR-195-5p-mediated effects in ESCC cells. Circ_0081069 was secreted from ESCC cells by being packaged into exosomes. Further, circ_0081069-Exo inhibited radiosensitivity in ESCC cells. Exosome-mediated transfer of circ_0081069 induced SPIN1 production by binding to miR-195-5p, further inhibiting radiosensitivity in ESCC.

Th1-involved immune infiltrates improve neoadjuvant chemoradiotherapy response of esophageal squamous cell carcinoma

Neoadjuvant chemoradiotherapy (NCRT) followed by surgery is recommended for locally advanced esophageal squamous cell carcinoma (ESCC) treatment. Patients who achieve a pathological complete response (pCR) have better survival. Our study aimed to discover immune-associated predictors of pCR in ESCC. Herein, we found that Th1-cell infiltration inferred from RNA sequencing was higher in the pCR group than in the non-pCR group. Multiplexed immunohistochemistry (mIHC) confirmed that Th1-, CD8+ T-, NK-, NKT-, and dendritic-cell infiltration was positively associated with pCR. The spatial relationships between Th1 cells and CD8+ T, NK, NKT, dendritic, or ESCC cells were significant pCR predictors. The active and desert subtypes were identified based on immune cell infiltration, and showed different pCR rates. In vitro experiments confirmed that Th1 cells inhibited the proliferation and improved the chemosensitivity and radiosensitivity of ESCC cells. Th1 cells upregulated interferon-gamma response signaling and antigen presentation pathways and downregulated lipid metabolism and MAPK pathways of ESCC cells. These findings highlight the important role of Th1 cells as the predictor of pCR and the regulator of chemosensitivity and radiosensitivity of ESCC, and suggest elevating Th1-infiltration as a strategy to improve NCRT response.

CBX4 contributes to radioresistance by regulating autophagic activity in esophageal squamous cell carcinoma.

BackgroundThe function of Chromobox 4 (CBX4) function has attracted attention in many cancer types due to its unique biological role; however, its mechanism in esophageal squamous cell carcinoma (ESCC) under radiotherapeutic treatment has not yet been investigated.MethodsSilencing of CBX4 was carried out in TE-13 and KYSE-150 cell lines. Cell proliferation, radiosensitivity, DNA damage, apoptosis, and cell cycle distribution were determined by Cell Counting Kit-8 (CCK-8), colony formation assay, immunofluorescence, flow cytometry, and immunoblot in vitro. In vivo xenograft models were also used to assess tumor cell growth and radioresistance. The underpinning mechanisms were explored based on pathway analysis and confirmed by rescue experiments, detecting cellular autophagy.ResultsKnockdown of CBX4 resulted in reduced tumor growth and enhanced radio-response in vivo and in vitro. Down-regulating CBX4 increased DNA damage, apoptotic rate, and G2/M arrest induced by radiation in ESCC cell lines. Gene Set Enrichment Analysis (GSEA) revealed that CBX4 was associated with cellular autophagy regulation. Enhanced radiosensitivity in ESCC cells silenced for CBX4 was partially blocked by autophagy inhibition (P<0.05). Beclin 1 was upregulated at the gene and protein levels in ESCC cells with CBX4 knockdown after irradiation, and overexpressing Beclin 1 reversed the radiosensitivity of ESCC cells with CBX4 knockdown (P<0.05).ConclusionsBy regulating autophagic activity, CBX4 contributes to radioresistance. Targeting CBX4 might constitute an efficient approach for increasing radiosensitivity in ESCC.

Transcription factor NFE2L3 promotes the proliferation of esophageal squamous cell carcinoma cells and causes radiotherapy resistance by regulating IL-6

ObjectiveTo scrutinize the impact of overexpression and interference of NFE2L3 on radiosensitivity of esophageal squamous cell carcinoma cells (ESCC) and its downstream mechanism and to assess whether NFE2L3 expression alters in vivo radiosensitivity of ESCC by developing a subcutaneous tumor model in mice. MethodsThrough RNA-Seq, we compared the differentially expressed genes between the ECA-109R cell line and its parent ECA-109 cell line. The differentially expressed genes were selected and verified by qRT-PCR. Transfection of ESCC cell lines with NFE2L3 inhibitor or mimic lentivirus constructs was done to study the activity of NFE2L3. To assess the effect of NFE2L3 on cellular growth and proliferation, clonogenic survival assay, EdU incorporation assay, and CCK-8 assay were done after irradiation. To probe how many irradiated DNA double-strand breaks were produced, the corresponding intensity of γ-H2AX foci were detected by immunofluorescence. Apoptotic cells were assayed by flow cytometry assay after irradiation; To investigate the downstream genes of NFE2L3, we knocked NFE2L3, and RNA-Seq was used to find out the downstream genes. qRT-PCR and western blot ensued to score associated protein profiles. The in vivo ESCC cell radiosensitivity was scrutinized by nude mouse xenograft models. ResultsThe differential genes between ECA-109R cells and its parent ECA-109 cells were compared by qRT-PCR to unveil a significant increase in NFE2L3 expression. Functional analysis indicated that NFE2L3 increased radioresistance in ESCC cells. Then, through high-throughput sequencing and bioinformatics analysis, IL-6 was found to be a hub gene that played a role downstream of NFE2L3 and was verified by qRT-PCR, western blot, and double luciferase reporter gene experiment. NFE2L3 could regulate ESCC cell radiosensitivity via the IL-6-STAT3 signaling pathway, and downregulation of IL-6 expression could reverse the effects of highly expressed NFE2L3. In vivo tumor xenograft experiments confirmed that NFE2L3 affects the sensitivity to radiation therapy. ConclusionNFE2L3 can affect the radiosensitivity of ESCC cells through IL-6 transcription and IL-6/STAT3 signaling pathway. This makes NFE2L3 a putative target to regulate ESCC cell radiosensitivity.

RETRACTED ARTICLE: Long non-coding RNA DIO3OS binds to microRNA-130b to restore radiosensitivity in esophageal squamous cell carcinoma by upregulating PAX9.

Esophageal squamous cell carcinoma (ESCC) ranks as one of the most deadly cancers worldwide due to its aggressive progression and poor treatment response. The long non-coding RNA (lncRNA)-microRNA (miRNA)-messenger RNA (mRNA) axis has been highlighted as a potency biomarker for enhancing the radiosensitivity of ESCC. Hence, we investigated the functional mechanism of the lncRNA DIO3OS/miR-130b/PAX9 axis in the radioresistance of ESCC cells. In cell experiments, we altered the miR-130b expression in ESCC cells using mimic or inhibitor to examine its effects on ESCC cell activities in response to 4 Gy irradiation, as well testing the involvement of lncRNA DIO3OS and the transcription factor gene PAX9. Tumor xenograft experiments were then conducted to observe the effect of miR-130b, lncRNA DIO3OS, and PAX9 on the radiosensitivity of ESCC cells in vivo. miR-130b was found to be highly expressed in ESCC. Downregulated miR-130b inhibited proliferation, invasion, and resistance to apoptosis in ESCC cells. LncRNA DIO3OS and PAX9 were downregulated in ESCC. The lncRNA DIO3OS could upregulate PAX9 by binding to miR-130b, which ultimately promoted the radiosensitivity of ESCC in vitro and in vivo. Taken together, lncRNA DIO3OS upregulates the expression of PAX9 by binding to miR-130b, ultimately promoting the radiosensitivity of ESCC.

IL-32 Promotes the Radiosensitivity of Esophageal Squamous Cell Carcinoma Cell through STAT3 Pathway.

Objective This study is set out to determine the relationship between IL-32 and radiosensitivity of esophageal squamous cell carcinoma (ESCC). Methods Western blot was adopted for measuring IL-32 expression in Eca-109 and TE-10 cells. Eca-109 and TE-10 cells with interference or overexpression of IL-32 were treated with the presence or absence of X-ray irradiation. Then, the use of CCK8 assay was to detect proliferation ability, and effects of IL-32 expression on radiosensitivity of ESCC were tested by colony formation assay. The cell apoptosis was detected using flow cytometry. STAT3 and p-STAT expression, and apoptotic protein Bax were detected by western blot. Results Colony formation assay and CCK8 assay showed that compared with the NC group without treatment, the growth of the ESCC cells, that is Eca-109 and TE-10, was significantly inhibited in the OE+IR group with highly expressed IL-32 and irradiation. In flow cytometry analysis, in Eca-109 and TE-10 cells, highly expressed IL-32 combined with irradiation significantly increased apoptosis compared with the control group. Highly expressed IL-32 has a synergistic effect with irradiation, inhibiting STAT3 and p-STAT3 expression and increasing apoptotic protein Bax expression. Conclusion IL-32 can improve the radiosensitivity of ESCC cells by inhibiting the STAT3 pathway. Therefore, IL-32 can be used as a new therapeutic target to provide a new attempt for radiotherapy of ESCC.

Elevated HNF1A expression promotes radiation-resistance via driving PI3K/AKT signaling pathway in esophageal squamous cell carcinoma cells.

Purpose: Radiotherapy is a major modality for treatment of local advanced esophageal squamous cell carcinoma (ESCC). Hepatocyte nuclear factor 1-alpha (HNF1A) is involved in regulation of tumor cell proliferation, apoptosis, cycle distribution, invasion metastasis and chemical resistance. The aim of this study was to investigate the effect of HNF1A on radiosensitivity of ESCC cells.Methods: In our study, HNF1A expression was verified from GEPIA in multiple types of cancer. The prognostic value of HNF1A in ESCC was obtained by TCGA database. In addition, the expression of HNF1A in ESCC cell lines was verified by western blot. Subsequently, lentiviruses were used to construct HNF1A overexpressed cell lines TE1 and KYSE150.Then, the roles of HNF1A on cell proliferation, invasion, apoptosis, cell cycle distribution and radiosensitivity were verified. Furthermore, the relationship between HNF1A and γH2AX were determined by western blot and immunofluorescence. We also detected the expression changes of key factors in PI3K/AKT pathway after overexpression of HNF1A.Results: The results showed that the overexpression of HNF1A promoted cell proliferation and invasion with or without irradiation (IR), and potently radiation-resistance ESCC cells with a sensitization enhancement ratio (SER) of 0.76 and 0.87. In addition, HNF1A regulated Cyclin D1 and CDK4 proteins to promote the transition from radiation-induced G0/G1 phase arrest to S phase, and coordinated BAX and BCL2 proteins to reduce the occurrence of radiation-induced apoptosis. It was worth noting that HNF1A might be involved in radiation-induced DNA damage repair by regulating γH2AX though PI3K/AKT signal pathway.Conclusion: Our study preliminarily suggested that HNF1A was associated with the progression and radiosensitivity of ESCC cells, and it might reduce the radiosensitivity of ESCC cells by promoting cell proliferation, releasing G0/G1 phase arrest, reducing apoptosis, and regulating the expression of γH2AX protein though driving PI3K/AKT signal pathway.

EphA5 Silencing Increases the Radiosensitivity of ESCC Cells Through ATM-Dependent Pathway.

BackgroundRadiotherapy is one of the most important treatments for esophageal squamous cell carcinoma (ESCC). Previously, we found that EphA5 expression was increased in ESCC cells and tumor tissues. Studies from other groups reported that EphA5 is abnormally expressed in numerous malignant tumors and may be involved in the radiosensitivity of lung cancer. However, the role of EphA5 in radiotherapy for ESCC remains unclear.MethodsThe siRNA sequences against human EPHA5 were transfected to the ESCC cells (KYSE150 and KYSE450). After ionizing radiation (IR), cell viability and colony formation assays were used to test the changes of cell proliferation in EphA5-silenced cells. Flow cytometry analysis was performed to investigate the cell apoptosis and cycle in the irradiated cells interfered by siRNA. The key molecules involved in cell cycle checkpoints and DNA damage repair were evaluated by Western blot and immunofluorescence.ResultsCCK8 assay and clonogenic assay showed that the proliferation of EphA5-silenced ESCC cells was inhibited after IR. At 24 h post-IR treatment, we found that the G1/S checkpoint triggered by DNA damage in EphA5-silenced cells was defective. γ-H2AX foci in the irradiated EphA5-silenced cells were impaired at 0.5 h post-IR treatment as well as ATM activation. The defective activation of ATM resulted in a decrease of p-Chk2, p-p53 and p21 expression.ConclusionIn conclusion, these results indicate that EphA5 silencing increases radiosensitivity in ESCC cells through ATM-dependent pathway, which provides a potential target for the radiotherapy in ESCC.

Long Non-Coding RNAs as Strategic Molecules to Augment the Radiation Therapy in Esophageal Squamous Cell Carcinoma.

Intrinsic resistance to ionizing radiation is the major impediment in the treatment and clinical management of esophageal squamous cell carcinoma (ESCC), leading to tumor relapse and poor prognosis. Although several biological and molecular mechanisms are responsible for resistance to radiotherapy in ESCC, the molecule(s) involved in predicting radiotherapy response and prognosis are still lacking, thus requiring a detailed understanding. Recent studies have demonstrated an imperative correlation amongst several long non-coding RNAs and their involvement in complex cellular networks like DNA damage and repair, cell cycle, apoptosis, proliferation, and epithelial-mesenchymal transition. Additionally, accumulating evidence has suggested abnormal expression of lncRNAs in malignant tumor cells before and after radiotherapy effects in tumor cells’ sensitivity. Thus, lncRNAs indeed represent unique molecules that can influence tumor cell susceptibility for various clinical interventions. On this note, herein, we have summarized the current status of lncRNAs in augmenting resistance/sensitivity in ESCC against radiotherapy. In addition, we have also discussed various strategies to increase the radiosensitivity in ESCC cells under clinical settings.

Upregulation of miR-519 enhances radiosensitivity of esophageal squamous cell carcinoma trough targeting PI3K/AKT/mTOR signaling pathway.

MicroRNA-519 (miR-519) has been previously reported to function as a tumor suppressor in several types of malignancies. This study aimed to probe the biological role of miR-519 in esophageal squamous cell carcinoma (ESCC). qRT-PCR was utilized to test the miR-519 expression level in ESCC tissues and cells. Clinical value of miR-519 was investigated by Kaplan-Meier method. Function assays were conducted to determine the role of miR-519 in radioresistance of ESCC cells. The miR-519-regulated pathways were determined by Kyoto Encyclopedia of Genes and Genomes pathway analysis. Low expression level of miR-519 was closely correlated with the poor prognosis for overall survival of ESCC patients or patients who received radiotherapy. Functional assays indicated that upregulation of miR-519 made ESCC cells more sensitive to γ-ray radiation and facilitated ESCC cell apoptosis triggered by irradiation treatment via regulating DNA response. Ectopic expression of miR-519 decreased the level of p-AKT and p-mTOR, thus inactivating PI3K/AKT/mTOR signaling pathway after irradiation. These observations elucidated that upregulated miR-519 is closely correlated with the radiosensitivity of ESCC cells, which may contribute to finding a new promising target for improving the efficiency of radiotherapy in patients with ESCC.

Up-regulation of microRNA-136 induces apoptosis and radiosensitivity of esophageal squamous cell carcinoma cells by inhibiting the expression of MUC1

ObjectiveThis present study is performed to figure out the role of microRNA-136 (miR-136) in radiosensitivity of esophageal squamous cell carcinoma (ESCC) cells through the regulation of MUC1. MethodsSeventy-four ESCC patients were divided into radiotherapy sensitive group and radiotherapy resistance group. Colony formation assay and flow cytometry were used to test the radiosensitivity of radiotherapy resistant strain and parent strain. The expression of miR-136 between radiotherapy resistant strain and parent strain was detected by RT-qPCR, and the expression of miR-136 in Eca109 and TE-1 cells as well as Eca109-R and TE-1-R cells was detected after different doses of X-ray irradiation. Eca109 and TE-1 cells as well as Eca109-R and TE-1-R cells with overexpression of miR-136 or co-overexpression of miR-136 and MUC1 were constructed. Cell proliferation, colony formation and apoptosis was detected by CCK-8 assay, colony formation assay, and flow cytometry, respectively. ResultsThe expression of miR-136 in ESCC tissues was lower and MUC1 mRNA and protein expression was higher than that in adjacent normal tissues. The expression of miR-136 was negatively correlated with the expression of MUC1 mRNA in ESCC. Low expression of miR-136 and high expression of MUC1 were associated with tumor size, lymph node metastasis and distant metastasis. The expression of miR-136 increased while the expression of MUC1 decreased in the radiotherapy sensitive group of ESCC patients relative to the radiotherapy resistant group. The colony formation ability of radiation resistant cell line was stronger than that of parent cell line, and the apoptosis rate showed an opposite trend. Up-regulation of miR-136 reduced the survival rate, suppressed colony formation ability and induced apoptosis of ESCC cells under irradiation, which was reversed by upregulated MUC1. ConclusionThis study demonstrates that up-regulation of miR-136 induces apoptosis and radiosensitivity of ESCC cells by inhibiting the expression of MUC1.

Long noncoding RNA MALAT1 promotes the stemness of esophageal squamous cell carcinoma by enhancing YAP transcriptional activity.

The tumor promoting roles of long noncoding RNA (lncRNA) MALAT1 have been revealed in various cancers; however, its roles in esophageal squamous cell carcinoma (ESCC) have not previously been disclosed. In this study, we found that MALAT1 expression was remarkably increased in ESCC cells compared to normal human esophageal epithelial cells. In addition, knockdown of MALAT1 attenuated the stemness of ESCC cells, as evidenced by a decrease in spheroid formation capacity, stemness marker expression and aldehyde dehydrogenase 1 activity. Moreover, MALAT1 knockdown decreased the migration ability of ESCC cells. Notably, knockdown of MALAT1 enhanced the radiosensitivity and chemosensitivity of ESCC cells. We also established that MALAT1 binds directly to Yes‐associated protein (YAP), thereby enhancing YAP protein expression and increasing YAP transcriptional activity. Overexpression of YAP partially rescued the effect of MALAT1 knockdown on stemness and radiosensitivity of ESCC cells. Overall, this study has identified that a novel MALAT1–YAP axis promotes the stemness of ESCC cells, and thus could be a potential target for treatment of ESCC.

LINC00473/miR-374a-5p regulates esophageal squamous cell carcinoma via targeting SPIN1 to weaken the effect of radiotherapy.

Esophageal squamous cell carcinoma (ESCC) is the most prevalent type in esophageal cancers. Despite accumulating achievements in treatments of ESCC, patients still suffer from recurrence because of the treatment failures, one of the reasons for which is radioresistance. Therefore, it is a necessity to explore the molecular mechanism underlying ESCC radioresistance. Long intergenic noncoding RNA 473 (LINC00473) has been reported to be aberrantly expressed in several human malignancies. However, its biological function in radiosensitivity of ESCC remains to be fully understood. This study explored the role of LINC00473 in radiosensitivity of ESCC cells and whether LINC00473 acted as a competing endogenous RNA to realize its modulation on radioresistance. We found that LINC00473 was markedly upregulated in ESCC tissues and cell lines, and its expression was remarkably related to cellular response to irradiation. In addition, knockdown of LINC00473 could sensitize ESCC cells to radiation in vitro. As for the underlying mechanism, we uncovered that there was a mutual inhibition between LINC00473 and miR-374a-5p. Spindlin1 (SPIN1) was verified as a downstream target of miR-374a-5p, and LINC00473 upregulated SPIN1 expression through negatively modulating miR-374a-5p expression. Furthermore, we revealed that SPIN1 could aggravate the radioresistance of ESCC cells. Finally, overexpression of SPIN1 reversed the LINC00473 silencing-enhanced radiosensitivity in ESCC cells. To sum up, we demonstrated that LINC00473 facilitated radioresistance by regulating the miR-374a-5p/SPIN1 axis in ESCC.

Raltitrexed increases radiation sensitivity of esophageal squamous carcinoma cells

BackgroundRadiation therapy remains an important therapeutic modality, especially for those patients who are not candidates for radical resection. Many strategies have been developed to increase the radiosensitivity of esophageal cancer, with some success.MethodsThis study was conducted to determine whether raltitrexed can enhance radiosensitivity of esophageal squamous cell carcinoma (ESCC). ESCC cell lines 24 h were incubated with raltitrexed or DMSO with or without subsequent irradiation. Cell Counting Kit assay-8 assay and clonogenic survival assay were used to measure the cell proliferation and radiosensitization, respectively. Flow cytometry was utilized to examine cell apoptosis and cell cycle distribution in different groups. Immunofluorescence analysis was performed to detect deoxyribonucleic acid (DNA) double-strand breaks. In addition, the expression levels of proteins that are involved in radiation induced signal transduction including Bax, Cyclin B1, Cdc2/pCdc2, and Cdc25C/pCdc25C were examined by western blot analysis.ResultsThe results indicated that raltitrexed enhanced radiosensitivity of ESCC cells with increased DNA double-strand breaks, the G2/M arrest, and the apoptosis of ESCC cells induced by radiation. The sensitization enhancement ratio of 1.23–2.10 was detected for ESCC cells with raltitrexed treatment in TE-13 cell line. In vitro, raltitrexed also increased the therapeutic effect of radiation in nude mice.ConclusionRaltitrexed increases the radiosensitivity of ESCC. This antimetabolite drug is promising for future clinical trials with concurrent radiation in esophageal cancer.

Long Non-Coding RNA DIO3OS Binds to microRNA-130b to Restore Radiosensitivity in Esophageal Squamous Cell Carcinoma by Upregulating PAX9

Background: Esophageal squamous cell carcinoma (ESCC) ranks as one of the most fatal cancers worldwide for its aggression and unsatisfactory survival rate. The long non-coding RNA (lncRNA)-microRNA (miRNA)-mRNA axis has been highlighted as a potency biomarker for enhancing the radiosensitivity of ESCC. Hence, we investigated the functional mechanism of the DIO3OS/miR-130b/paired box 9 (PAX9) axis in the radioresistance of ESCC cells. Methods: In cell experiments, we altered the miR-130b expression in ESCC cells using mimics or inhibitors to examine its effects on ESCC cell activities in response to 4 Gy irradiation, as well as the involvement of DIO3OS and PAX9. Tumor xenograft experiments were then conducted to observe the effect of miR-130b, DIO3OS and PAX9 on radiosensitivity of ESCC cells in vivo. Results: miR-130b was found to be highly-expressed in the ESCC. Downregulated miR-130b inhibited proliferation, invasion and resistance to apoptosis in ESCC cells. DIO3OS and PAX9 were reduced in ESCC. A notable finding revealed that miR-130b could bind to DIO3OS and PAX9 respectively. DIO3OS could upregulate PAX9 by binding to miR-130b, which ultimately promoted the radiosensitivity of ESCC in vitro and in vivo. Conclusion: Taken together, DIO3OS upregulates the expression of PAX9 by binding to miR-130b, ultimately promoting the radiosensitivity of ESCC. Funding Statement: The authors stated: None. Declaration of Interests: The authors stated: None. Ethics Approval Statement: The in vivo study adhering to the ARRIVE guidelines was carried out with the approval of the Ethics Committee of The First Affiliated Hospital of Zhengzhou University (ID: 201311005).

The vanillin derivative 6-bromine-5-hydroxy-4-methoxybenzaldehyde induces aberrant mitotic progression and enhances radio-sensitivity accompanying suppression the expression of PLK1 in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is the most common form of esophageal cancer in China. Since chemotherapy is the standard clinical intervention for advanced ESCC, the development of highly effective and minimal/non-toxic drugs is essential to improve the clinical outcome and prognosis of the patients. A novel derivative of vanillin, 6-bromine-5-hydroxy-4-methoxybenzaldehyde (BVAN08), has been recently reported to activate different cell death pathways in cancer cells. In this study, we demonstrate that BVAN08 exhibits a potent anti-proliferation effect on ESCC cells (TE-1 and ECA-109) by inhibiting the expression of PLK1, an important mitotic kinase. Consistent with this, BVAN08 induces mitotic arrest and chromosomal misalignment in ESCC cells. The disruption of microtubule nucleation around centrosomes is also observed in BVAN08 treated ESCC cells. Furthermore, BVAN08 enhances radio-sensitivity of ESCC cells by prolonging DNA damage repair. These findings underscore the potential value of BVAN08 in cancer therapeutics and demonstrate the underlying mechanism by which BVAN08 induces mitotic catastrophe and enhances radio-sensitivity in ESCC cells.

MicroRNA-381 enhances radiosensitivity in esophageal squamous cell carcinoma by targeting X-linked inhibitor of apoptosis protein.

BackgroundIncreasing evidence indicates that radioresistance remains a major problem in the treatment of patients with esophageal squamous cell carcinoma (ESCC). This study was designed to investigate the expression of microRNA-381 (miR-381) and its function in the radioresistance of ESCC.MethodsIn this study, miR-381 expression was first detected in ESCC cell lines and tissue samples by quantitative real-time polymerase chain reaction (qRT-PCR). Then, the effects of miR-381 expression on growth, apoptosis, and radiosensitivity of ESCC cells were analyzed by MTT, colony formation, and flow cytometry, respectively. Dual-luciferase reporter assays were performed to validate the regulation of a putative target of miR-381, in corroboration with qRT-PCR and Western blotting assays.ResultsESCC cell lines or tissues were found to express significantly lower miR-381 than normal esophageal epithelial cells or adjacent normal tissues, respectively. Ectopic expression of miR-381 in ESCC cell lines blocked proliferation, reduced colony formation, enhanced apoptosis, and increased radiosensitivity by enhancing irradiation-induced apoptosis. In addition, dual-luciferase reporter assays showed that miR-381 binds to the 3′-untranslated region of X-linked inhibitor of apoptosis protein (XIAP), suggesting that XIAP should be a direct target of miR-381. Re-expression of miR-381 suppressed XIAP protein expression in ESCC cells, and the effects of miR-381 upregulation on ESCC cells were found to be similar with silencing of XIAP. In addition, XIAP mRNA expression significantly increased in ESCC tissues and was inversely correlated with miR-381 expression.ConclusionThe results of this study suggest that miR-381/XIAP pathway contributed to the growth inhibition, increase in apoptosis, and enhancement of radiosensitivity in ESCC cells Therefore, miR-381 may be a potential therapeutic target in human ESCC.

STAT3 inhibitor stattic enhances radiosensitivity in esophageal squamous cell carcinoma.

The radioresistance of esophageal squamous cell carcinoma (ESCC) remains an obstacle for the effective radiotherapy of ESCC. This study aimed to investigate the radiosensitization of ESCC by signal transducer and activator of transcription 3 (STAT3) inhibitor stattic. ECA109, TE13, and KYSE150 cell lines were exposed to hypoxia and treated with stattic or radiation, alone or in combination. Cell proliferation, colony formation, apoptosis, and double-stranded DNA breaks (DSBs) were examined. In addition, ECA109 cells were xenografted into nude mice and treated with radiation and/or stattic. The levels of STAT3, p-STAT3, hypoxia-inducible factor 1α (HIF-1α), and vascular endothelial growth factor (VEGF) in ESCC cells and xenografts were detected by Western blot and immunohistochemical analysis. Our results showed that stattic efficiently radiosensitized ESCC cells and xenografts, especially under hypoxia. Moreover, stattic inhibited STAT3 activation and downregulated HIF-1α and VEGF expression. In conclusion, stattic confers radiosensitivity in ESCC cells in vitro and in vivo and is a potential adjuvant for the radiotherapy of ESCC in the clinical setting.

Increased miRNA-22 expression sensitizes esophageal squamous cell carcinoma to irradiation

miRNA-22 was previously reported to be a tumor suppressor. The aim of this study was to explore the expression and function of miRNA-22 in esophageal squamous cell carcinoma (ESCC). Expression of miRNA-22 in 100 ESCC tissues was examined by q-PCR. The correlation between miRNA-22 level and clinicopathological features was analyzed using SPSS16.0 statistical software. Moreover, the effect of miRNA-22 expression on radiosensitivity of ESCC cells was examined. miRNA-22 expression decreased in ESCC tissues, and statistical analyses showed that the expression of miRNA-22 was associated with the stage of clinical classification. No correlation was found between miRNA-22 expression and the overall survival of ESCC patients. However, significant positive correlation was found between miRNA-22 expression and the survival of patients who received radiotherapy (P < 0.05). Increased expression of miRNA-22 sensitized ESCC cells to γ-ray radiation and promoted the apoptosis of ESCC cells induced by γ-ray radiation. Increased expression level of miRNA-22 had effects on Rad51 expression after irradiation. These results demonstrate for the first time that decreased miRNA-22 expression correlates with increased radiotherapy resistance of ESCC, and that this effect is mediated, at least in part, by the Rad51 pathway.

Abstract 364: Impact of glucocorticoid in patients with locally advanced esophageal cancer treated with concurrent chemoradiotherapy

Abstract Background: Concerns about the effect of glucocorticoids (GC) on tumor growth and chemosensitivity have been raised recently. Our pervious study shows that GC receptor is highly expressed in esophageal squamous cell carcinoma (ESCC) tumor tissues (Histopathology 2008;52:314-324). This study sought to further characterize the GC effect on the efficacy of conventional anti-cancer therapy to ESCC. Materials and Methods:The in vitro study was performed in 2 esophagus cell lines: KYSE-70 and KYSE-410. The cell viability is determined by MTT assay and clonogenic assay. The effect of GC on cytotoxic treatment -induced apoptotic cell death was determined by flow cytometric and Western blot analysis. Further, we retrospectively analyzed impact of GC usage on the outcomes of 92 patients with locally advanced ESCC who received preoperative concurrent chemoradiotherapy in a prospective clinical trial. Among 92 locally advanced ESCC patients, 39 patients who received GC twice weekly for four to six weeks (a total of eight doses or more) and 53 patients who received GC only two doses in the first week at discretion of individual physicians. Results: In vitro study showed pretreatment of GC confer resistance to cytotoxic agents including paclitaxel, gemcitabine and 5-FU, and resistance to irradiation. The effect of increase chemo-resistance by GC may be through decrease of the apoptosis according to PI/annexin V staining flow cytometric study and Western blot study. In the retrospective clinical study, the two groups were well balanced with respect to disease stage and other prognostic factors. Multivariate analysis showed that corticosteroid usage and performance status were independently prognostic of survivals. The median overall survivals of the two-dose group the eight-dose-or-more group were 38.4 and 15.1 months, (p = 0.089), respectively. The median progression-free survivals were 27.5 and 9.4 months (p = 0.024), respectively. Conclusion: This data suggest that GC decrease chemo-sensitivity and radio-sensitivity of ESCC cells. Frequent usage of GC during concurrent chemoradiotherapy may have a detrimental effect on patients with locally advanced ESCC. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 364. doi:10.1158/1538-7445.AM2011-364