Expression and Comparison of Cbl-b in Lung Squamous Cell Carcinoma and Adenocarcinoma

The role of CBL family ubiquitin ligases in cancer progression and therapeutic strategies

The CBL (Casitas B-lineage lymphoma) family, as a class of ubiquitin ligases, can regulate signal transduction and activate receptor tyrosine kinases through various tyrosine kinase-dependent pathways. There are three members of the family: c-CBL, CBL-b, and CBL-c. Numerous studies have demonstrated the important role of CBL in various cellular pathways, particularly those involved in the occurrence and progression of cancer, hematopoietic development, and regulation of T cell receptors. Therefore, the purpose of this review is to comprehensively summarize the function and regulatory role of CBL family proteins in different human tumors, as well as the progress of drug research targeting CBL family, so as to provide a broader clinical measurement strategy for the treatment of tumors.

ZEB1-activated Notch1 promotes circulating tumor cell migration and invasion in lung squamous cell carcinoma

BACKGROUND

Lung squamous cell carcinoma (LUSC) is recognized as the major subtypes of non-small cell lung cancer (NSCLC). Circulating tumor cells (CTCs) are critical players in tumor metastasis. A molecular profiling of CTCs has previously identified notch receptor 1 (Notch1) as an important mediator in NSCLC. Therefore, we investigate Notch1 roles in LUSC and its related mechanisms.

METHODS

The serum levels of Notch1 were measured by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The CTCs isolated from blood samples were characterized via an immunofluorescence method. Cell motion was determined using Transwell chambers. The regulatory relationship between Notch1 and zinc finger E-box-binding homeobox 1 (ZEB1) was verified by chromatin immunoprecipitation (ChIP) and luciferase reporter assays. The protein levels were detected by western blotting.

RESULTS

Higher Notch1 expression in patients with LUSC than that in normal controls was observed. Notch1 knockdown inhibited cell motion and epithelial-mesenchymal transition (EMT). ZEB1 transcriptionally activated Notch1. ZEB1 upregulation exacerbated the malignant phenotypes of CTCs.

CONCLUSION

ZEB1-activated Notch1 promotes malignant phenotypes of CTCs in LUSC and indicates poor prognosis.

Altered Mitochondrial Dynamics, Biogenesis, and Functions in the Paclitaxel-Resistant Lung Adenocarcinoma Cell Line A549/Taxol

BACKGROUND Chemoresistance is a primary hindrance for current cancer treatments. The influence of abnormal mitochondria in chemotherapy resistance is not well known. To explore the correlation between mitochondria and acquired chemoresistance, this work studied alterations in mitochondrial dynamics, biogenesis, and functions for paclitaxel-resistant cancer cell line A549/Taxol and its parental line A549. MATERIAL AND METHODS Mitochondrial morphology was observed by transmission electron microscopy and confocal microscopy. We measured the mitochondrial mass and mitochondrial membrane potential using fluorescent dyes. The glucose metabolic profile and ATP (adenosine triphosphate) content were determined by bioluminescent cell assays. Seahorse bio-energy analyzer XF24 was used to detect the mitochondrial respiratory function. The expressions of mitochondrial dynamics and biogenesis related genes were quantified using real-time polymerase chain reaction. RESULTS We observed fusion morphology of the mitochondrial network in A549/Taxol cells, with upregulation of fusion genes (Mfn1 and Mfn2) and downregulation of fission gene Fis1. In A549/Taxol cells, mitochondrial mass showed a significant decrease, while the mitochondrial biogenesis pathway was strongly activated. Despite the decreased mitochondrial membrane potential, the capability for mitochondrial respiration was not impaired in A549/Taxol cells. CONCLUSIONS Our study revealed a series changes of mitochondrial characteristics in paclitaxel-resistant cells. Mfn1 and Mfn2 and PGC-1alpha increased, while Fis1 expression and mitochondrial oxidative phosphorylation decreased in A549/Taxol cell lines. These changes to mitochondrial fusion, fission, and biological function contributed to the occurrence of paclitaxel resistance in tumor cells which induced paclitaxel resistance.