Our data suggest that combination therapy with hRT schedules extending into the period during which treatment-induced T cells infiltrate the irradiated tumor can provoke local and systemic antitumor effects similar to those with therapy using shorter schedules, if the regional lymph nodes supply sufficient tumor-specific T cells. This has implications for planning clinical RT/immune checkpoint blockade trials.
High-risk human papillomavirus (HPV), especially HPV16, correlates with cancerogenesis of human esophageal squamous cell carcinoma (ESCC) and we have reported that HPV16 related with a poor prognosis of ESCC patients in China. We aim to investigate the potential role and mechanism of HPV16 in ESCC development and progress. Our following researches demonstrated that ESCC cells which were stably transfected by HPV16 E6-E7 lentiviral vector showed a remarkable cancer stem-like cells (CSCs) phenotype, such as: migration, invasion, spherogenesis, high expression of CSCs marker in ESCC---p75NTR, chemoresistance, radioresistance, anti-apoptosis ability in vitro and cancerogenesis in vivo. HPV16 E6-E7 induced PI3K/Akt signaling pathway activation and this affect could be effectively inhibited by LY294002, a specific PI3K inhibitor. It was also indicated that the inhibition of PI3K/Akt signaling pathway by PI3K and Akt siRNA reverse the effect which induced by HPV16 E6-E7 in ESCC cells. Taken together, the present study demonstrates that HPV16 E6-E7 promotes CSCs phenotype in ESCC cells through the activation of PI3K/Akt signaling pathway. Targeting the PI3K/Akt signaling pathway in HPV16 positive tissues is an available therapeutic for ESCC patients.
Radiation therapy is one of the most important treatments for unresectable and locally advanced esophageal squamous cell carcinoma (ESCC), however, the response to radiotherapy is sometimes limited by the development of radioresistance. Sinomenine hydrochloride (SH) has anticancer activity, but its effect on the radiosensitivity of ESCC is unclear. We determined the effect of SH on the radiosensitivity of ESCC cells and elucidated its potential radiosensitization mechanisms in vitro and in vivo. ESCC cells were subjected to SH and radiation, both separately and in combination. Untreated cells served as controls. The CCK-8 assay was used to evaluate cell proliferation, and the clonogenic assay to estimate radiosensitization. Flow cytometry was used to investigate cell cycle phases and cell apoptosis. Bcl-2, Bax, cyclin B1, CDK1, Ku86, Ku70, and Rad51 expression was evaluated using western blotting. In vivo, tumor xenografts were created using BALB/c nude mice. Tumor-growth inhibition was recorded, and Ki-67 and Bax expression in the tumor tissues was assessed using immunohistochemistry. SH inhibited ESCC cell growth and markedly increased their radiosensitivity by inducing G2/M phase arrest. SH combined with radiation therapy significantly increased ESCC cell apoptosis. The molecular mechanism by which SH enhanced radiosensitivity of ESCC cells was related to Bcl-2, cyclin B1, CDK1, Ku86, Ku70, and Rad51 downregulation and Bax protein expression upregulation. SH combined with radiation considerably delayed the growth of tumor xenografts in vivo. Immunohistochemical analysis showed that in the SH combined with radiation group, the expression of Bax was significantly higher while that of Ki-67 was lower than the expressions in the control groups. Taken together, our findings showed that SH could improve the sensitivity of radiation in ESCC cells by inducing G2/M phase arrest, promoting radiation-induced apoptosis and inhibiting DSB-repair pathways. SH appears to be a prospective radiosensitizer for improving the efficacy of radiotherapy for ESCC.
The available promoters in the Pichia pastoris expression platform are still limited. We selected and identified a novel strong constitutive promoter, P GCW14 , and tested its promoter activity using enhanced green fluorescent protein (EGFP) as a reporter. Potential promoter regions of P GCW14 were cloned upstream of the EGFP gene and promoter activity was analyzed by measuring fluorescence intensity. P GCW14 exhibited significantly stronger promoter activity than the classic strong constitutive promoters P TEF1 and P GAP under various carbon sources, suggesting that P GCW14 is a strong and constitutive promoter. Hence, P GCW14 can be used as a promoter for high-level expression of heterologous proteins.
PTEN pseudogene (PTENP1) has a tumor suppressive role in multiple cancers. However, its involvement in esophageal squamous cell carcinoma (ESCC) remains largely unknown. In this study, we set out to identify the role of PTENP1 in the development of ESCC. Gene Expression Omnibus database was employed to investigate the expression of PTENP1 in ESCC. sRNA target Database (StarBase v2.0) was used to query the downstream of PTENP1. Next, both in vitro and in vivo experiments were employed to explore the function. Cell proliferation was evaluated by CCK‐8, soft agar, and colony formation assays. Expression of relative genes was assessed by quantitative real‐time PCR (qRT‐PCR) and Western blotting. 3′UTR luciferase assay was used to confirm the miRNA binding. The clinical significance of PTENP1 was further validated by immunohistochemistry (IHC) and correlation with clinicopathological indicators in additional samples (n = 93). We found expression of PTENP1 in ESCC was lower than that in the corresponding adjacent normal tissues (n = 17). Overexpression of PTENP1 in Eca109 and TE‐1 cells resulted in inhibited proliferation and altered expression of SOCS6‐p‐STAT3‐HIF‐1α pathway both in vitro and in vivo. Subsequent IHC reported a similar trend in human ESCC samples. 3′UTR luciferase assay demonstrated that PTENP1 3′UTR decoyed miR‐17‐5p from binding to SOCS6. Moreover, PTENP1 expression was correlated with clinicopathological indicators to varying degrees, including histological grade, TNM stage, infiltration depth, lymph node metastasis, and overall survival. Taken together, these results suggested an anti‐oncogenic role of PTENP1. Meanwhile, PTENP1 may also serve as a candidate of prognostic indicator for ESCC patients.
BackgroundPrevious studies indicate that human papillomavirus 16 (HPV16) infection plays a pivotal role in the etiology of esophageal squamous cell carcinoma (ESCC). We aim to detect the influence of HPV16 infection on ESCC patient prognosis.Patients and methodsImmunohistochemical staining for HPV16 E6 oncoprotein, the low-affinity p75 neurotrophin receptor (p75NTR), and phosphatidylinositol 3-kinase (PI3K) was performed on 103 archived surgical specimens from patients with ESCC and 54 control samples from patients with benign esophageal tumor or inflammatory lesions. All patients were from the Shaan Xi Province, People’s Republic of China.ResultsHPV16 E6 expression was significantly higher in the ESCC group (P<0.05). HPV16 E6 expression was significantly higher in men than in women (P<0.05). p75NTR expression was higher in those aged >56 years (P<0.05). PI3K expression was higher in those with a more advanced histopathological grade (P<0.05). There was a positive correlation between HPV16 E6 and p75NTR expression (r=0.547, P<0.001) and between p75NTR and PI3K expression (r=0.364, P<0.001). In 100 evaluable patients, the 5-year overall survival (OS) rate was 11%. In patients with ESCC, HPV16 E6 and PI3K expression were negatively correlated with the 3-year OS (P<0.05), 5-year OS (P<0.05), and progression-free survival (P<0.05).ConclusionHPV16 infection likely contributes to the etiology of ESCC patients in Shaan Xi, People’s Republic of China. HPV16 infection status and PI3K expression levels could be useful for predicting prognosis in patients with ESCC.
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