Although it is known that ataxia-telangiectasia mutated (ATM) and interleukin 6 (IL-6) contribute to multiple drug resistance (MDR) in tumor chemotherapy, the exact role of ATM activation in MDR resulting from increased IL-6 expression is still unclear. In the present study, we demonstrate that the activation of the ATM-NF-kappaB pathway, resulting from increased IL-6 expression, plays a central role in augmented chemoresistance in lung cancer cell lines. This result was supported by the increased expressions of Bcl-2, Mcl-1, Bcl-xl, and the upregulation of MDR-associated protein ABCG2. The higher level of IL-6 reveals not only higher ATM/NF-kappaB activity but also increased expressions of ABCG2, Bcl-2, Mcl-1 and Bcl-xl. Most importantly, lung cancer cells themselves upregulated IL-6 secretion by activating the p38/NF-kappaB pathway through treatment with cisplatin and camptothecin. Taken together, these findings demonstrate that chemotherapeutic agents increase IL-6 expression, hence activating the ATM/NF-kappaB pathway, augmenting anti-apoptotic protein expression and contributing to MDR. This indicates that both IL-6 and ATM are potential targets for the treatment of chemotherapeutic resistance in lung cancer.
Dysregulation of the Wnt/β-catenin signaling pathway is critically involved in gastric cancer (GC) progression. However, current Wnt pathway inhibitors being studied in preclinical or clinical settings for other cancers such as colorectal and pancreatic cancers are either too cytotoxic or insufficiently efficacious for GC. Thus, we screened new potent targets from β-catenin destruction complex associated with GC progression from clinical samples, and found that scaffolding protein RACK1 deficiency plays a significant role in GC progression, but not APC, AXIN, and GSK3β. Then, we identified its upstream regulator UBE2T which promotes GC progression via hyperactivating the Wnt/β-catenin signaling pathway through the ubiquitination and degradation of RACK1 at the lysine K172, K225, and K257 residues independent of an E3 ligase. Indeed, UBE2T protein level is negatively associated with prognosis in GC patients, suggesting that UBE2T is a promising target for GC therapy. Furthermore, we identified a novel UBE2T inhibitor, M435-1279, and suggested that M435-1279 acts inhibit the Wnt/β-catenin signaling pathway hyperactivation through blocking UBE2T-mediated degradation of RACK1, resulting in suppression of GC progression with lower cytotoxicity in the meantime. Overall, we found that increased UBE2T levels promote GC progression via the ubiquitination of RACK1 and identified a novel potent inhibitor providing a balance between growth inhibition and cytotoxicity as well, which offer a new opportunity for the specific GC patients with aberrant Wnt/β-catenin signaling.
High-throughput profiling of in situ gene expression represents a major advance towards the systematic understanding of tissue complexity. Applied with enough capture area and high sample throughput it will help to define the spatio-temporal dynamics of gene expression in tissues and organisms. Yet, current technologies have considerable bottlenecks that limit widespread application. Here, we have combined DNA nanoball (DNB) patterned array chips and in situ RNA capture to develop Stereo-seq (Spatio-Temporal Enhanced REsolution Omics-sequencing). This approach allows high sample throughput transcriptomic profiling of histological sections at unprecedented (nanoscale) resolution with areas expandable to centimeter scale, high sensitivity and homogenous capture rate. As proof of principle, we applied Stereo-seq to the adult mouse brain and sagittal sections of E11.5 and E16.5 mouse embryos. Thanks to its unique features and amenability to additional modifications, Stereo-seq can pave the way for the systematic spatially resolved-omics characterization of tissues and organisms.
Lung adenocarcinoma is the most frequently histologic subtype and the most histologically heterogeneous form of lung cancer. De-regulation of Wnt/β-catenin signaling pathway is implicated in lung carcinogenesis. SOX7, as a member of high mobility group (HMG) transcription factor family, plays a role in the modulation of the Wnt/β-catenin signaling pathway. However, the expression pattern and clinicopathological significance of SOX7 in patients with lung adenocarcinoma is still unclear. To address this problem, the SOX7 mRNA expression was detected by quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR). Immunohistochemical studies were performed on 288 pairs of adjacent normal lung and lung adenocarcinoma tissues with complete follow-up records. Association of SOX7 protein expression with clinical outcomes was evaluated using the Kaplan-Meier method and a multivariate Cox proportional hazards regression model. SOX7 mRNA expression was significantly down-regulated in lung adenocarcinoma compared with matched adjacent normal tissues (P < 0.001). SOX7 protein was expressed in the cytoplasm of lung adenocarcinoma cells in 106/288 (36.8 %) of cases, whereas its immunoreactivities were predominantly located in the cytoplasm of the adjacent normal tissues. The reduced SOX7 expression was correlated with poor differentiation (P = 0.002), lymph node metastasis (P = 0.011) and advanced TNM stage (P = 0.006). Regarding patient survival, the overall survival and the disease-free survival rates were both significantly lower in patients with SOX7-negative tumors than in those with SOX7-positive tumors (P = 0.018 and 0.013, respectively). Multivariate analysis using a Cox proportional-hazards model demonstrated that SOX7 expression status was an independent prognostic factor predicting the overall survival and the disease-free survival of patients with lung adenocarcinoma (P = 0.021 and 0.016, respectively).Our data suggest that the decreased expression of SOX7 is an important feature of lung adenocarcinoma. The expression level of SOX protein may be a useful prognostic marker for patients with lung adenocarcinoma.
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