No abstract

BackgroundDistant metastasis is the major cause of mortality in patients with locally advanced rectal cancer (LARC) following neoadjuvant chemoradiotherapy. Local radiotherapy can trigger an abscopal response to metastatic tumor cells. However, the abscopal effect is a rare event. CD4+ regulatory T (Treg) cell is a highly immune-suppressive subset which impedes immune surveillance against cancer, prevents the development of effective antitumor immunity and promotes tumor progression. We assume that the exploitation of the proimmunogenic effects of radiotherapy with anti-CD25 or anti-Cytotoxic T-Lymphocyte Associated Protein 4 (anti-CTLA4) monoclonal antibodies (mAbs) may enhance the local and abscopal effects in rectal cancer and improve the therapeutic outcome.MethodsmRNA expression profiling of 81 pretreatment biopsy samples from LARC patients who received neoadjuvant radiotherapy (nRT) was performed to analyze the correlation between gene expression and prognosis. A retrospective analysis of patients with rectal cancer with distant metastasis or synchronous extracolonic cancers was performed to evaluate the abscopal effect of radiotherapy on rectal cancer. Two different dual-tumor mouse models were established to investigate the efficacy of single dose and dose-fractionated radiotherapy combined with anti-CD25 or anti-CTLA4 and anti-Programmed cell death 1 ligand 1 (anti-PD1) mAbs on the local tumor growth and liver metastasis. The univariate Cox regression analysis, one-way analysis of variance, Dunnett’s test, a mixed-effect linear model and Kaplan-Meier survival analysis were used to calculate p values.ResultsThe proportion of Tregs in pre-nRT biopsies was negatively correlated with prognosis (p=0.007). The retrospective analysis showed that regressing liver metastases were infiltrated by CD8+ T cells. In contrast, stable/progressing metastases and synchronous extracolonic cancers were characterized by PD1+ T cells and Tregs infiltration. Animal experiment results demonstrated that the combination of radiotherapy and anti-CD25/CTLA4 mAb resulted in a significant increase in CD8+ T cells and CD8+/CD4+ ratio in primary and secondary tumors compared with the irradiation alone group (all p<0.05 or p<0.01). The combined treatment was able to decrease Tregs, PD1+CD8+ and PD1+CD4+ T cells (p<0.05), suppress locally irradiated and distal unirradiated tumor growth, and improve overall survival rate. Radiotherapy in conjunction with anti-CTLA4 reduced liver metastasis (p<0.05).ConclusionsThese data indicated that radiotherapy plus depletion of Tregs was able to improve the antitumor response and generate an abscopal effect.

BACKGROUND: MicroRNA-145 (miR-145) has been reported to be a tumor-suppressing agent in several studies. It can repress pluripotency and control human embryonic stem cell differentiation by regulating the core pluripotency factor OCT4. However, it is not known whether miR-145 can play a role in inducing tumor cell differentiation and repressing growth of tumors. METHODS: Ishikawa cells, the established human endometrial cancer cells, were treated with miR-145 mimics, inhibitor, or small interfering RNA OCT4. miR-145 levels were assayed using TaqMan microRNA assays, and the messenger RNA levels of OCT4 and the differentiation marker glycodelin were measured using realtime polymerase chain reaction. The protein levels of OCT4 and glycodelin were characterized via flow cytometry, western blotting, and immunohistochemistry. In vivo activity was measured in a xenograft mouse model. RESULTS: Up-regulating miR-145 reduced the expression of OCT4 and induced the differentiation of Ishikawa cells to closely resemble normal endometrial epithelium both in vitro and in vivo. miR-145 successfully inhibited tumor growth. We also found that in patients with endometrial carcinoma, miR-145 and OCT4 were expressed in tissues, and there was a relationship between miR-145, OCT4, and the degree of tumor cell differentiation. CONCLUSIONS: Our results strongly suggested that miR-145 is a tumor cell differentiation-inducing agent in endometrial carcinoma, and that miR-145 or OCT4 may be useful markers for grading endometrial carcinoma. Cancer 2011;117:3989-

Topical intralesional BCG-PSN injection is as effective as TA for erosive OLP, which suggests that topical intralesional BCG-PSN injection can be a promising therapeutic alternative for erosive OLP, especially for those insensitive, or even resistant, to glucocorticoids.

No abstract