Expressions of programmed death (PD)-1 and PD-1 ligand (PD-L1) in cervical intraepithelial neoplasia and cervical squamous cell carcinomas are of prognostic value and associated with human papillomavirus status.

AIM: The programmed death 1/programmed death 1 ligand (PD-1/PD-L1) pathway can decrease the immune clearance effects of antigen-presenting cells and T lymphocytes to promote immune evasion of cervical cancer cells. However, the effects of this pathway on cervical intraepithelial neoplasia (CIN) progression and squamous cell carcinoma (SCC) metastasis are not clear. We herein investigated whether human papillomavirus infection could affect PD-1 and PD-L1 expression in CIN, and whether their expression is associated with CIN progression and SCC metastasis. METHODS: We collected paraffin-embedded samples from two cohorts of patients: (i) CIN samples from cohort I (40 women who tested positive or negative for high-risk human papillomavirus [HR-HPV] with grades 0, I, and II-III CIN); and (ii) paired primary and metastatic tumor samples from cohort II (20 SCC patients with or without metastasis). Immunohistochemistry was used to detect expressions of PD-L1 in tumor cells and PD-1 in tumor-associated macrophages and tumor-infiltrating lymphocytes. We also measured P16INK4a expression and interferon-γ levels in the cervical tissues. RESULTS: The most common HPV type seen in both cohorts of patients was HPV16, followed by HPV18. Increase in PD-L1 and PD-1 expression was positively correlated with HPV-positivity, increase in CIN grade, and tumor metastasis. Furthermore, upregulation of the PD-1/PD-L1 pathway was associated with decreased expression of the pro-inflammatory cytokine, interferon-γ and increased expression of P16INK4a . CONCLUSION: Expression of PD-L1 and PD-1 could be used as clinical prognostic biomarkers for evaluating CIN and cervical cancer because of its positive correlation with CIN progression and tumor metastasis.

The mechanisms and significance of up-regulation of RhoB expression by hypoxia and glucocorticoid in rat lung and A549 cells.

Small guanosine triphosphate (GTP)-binding protein RhoB is an important stress sensor and contributes to the regulation of cytoskeletal organization, cell proliferation and survival. However, whether RhoB is involved in the hypoxic response and action of glucocorticoid (GC) is largely unknown. In this study, we investigated the effects of hypoxia or/and GC on the expression and activition of RhoB in the lung of rats and human A549 lung carcinoma cells, and further studied its mechanism and significance. We found that hypoxia and dexamethasone (Dex), a synethic GC, not only significantly increased the expression and activation of RhoB independently but also coregulated the expresion of RhoB in vitro and in vivo. Up-regulation of RhoB by hypoxia was in part through stabilizing the RhoB mRNA and protein. Inhibiting hypoxia-activated hypoxia-inducible transcription factor-1α (HIF-1α), c-Jun N-terminal kinase (JNK) or extracellular signal-regulated kinase (ERK) with their specific inhibitors significantly decreased hypoxia-induced RhoB expression, indicating that HIF-1α, JNK and ERK are involved in the up-regulation of RhoB in hypoxia. Furthermore, we found that knockdown of RhoB expression by RhoB siRNA not only significantly reduced hypoxia-enhanced cell migration and cell survival in hypoxia but also increased the sensitivity of cell to paclitaxel (PTX), a chemotherapeutic agent, and reduced Dex-enhanced resistance to PTX-chemotherapy in A549 cells. Taken together, the novel data revealed that hypoxia and Dex increased the expression and activation of RhoB, which is important for hypoxic adaptation and hypoxia-accelerated progression of lung cancer cells. RhoB also enhanced the resistance of cell to PTX-chemotherapy and mediated the pro-survival effect of Dex.