Prognostic value of circulating tumor cells and its association with the expression of cancer stem cells in nasopharyngeal carcinoma patients.

The release of circulating tumor cells (CTCs) into vasculature is an early event in the metastatic process and the detection of CTCs has been widely used clinically. In addition, cancer stem cells (CSCs) are the source of distant metastasis. However, the relationship between CTCs and CSCs in nasopharyngeal carcinoma (NPC) patients was largely unknown. A total of 93 NPC patients were enrolled in this study. The CTCs in the peripheral blood were detected. The expression of ALDH1A1 in the tumor tissues of the corresponding patients was detected using immunohistochemistry (IHC). The prognostic value of CTCs level and the correlation with the expression of ALDH1A1 was evaluated. Data showed that the detection of CTCs was positively correlated with metastasis (p<0.001). The positive detection of CTCs was also associated with poor overall survival (p=0.025). CTCs ≥2 demonstrated good specificity and sensitivity in predicting distant metastasis, while CTCs ≥8 demonstrated better specificity and sensitivity in predicting prognosis than CTCs ≥2. Furthermore, we found that there was a positive relationship between the detection of CTCs and the expression of ALDH1A1 (p=0.001). The prognosis analysis also demonstrated that high ALDH1A1 expression was correlated with poor overall survival (p=0.006). Our study demonstrated a positive correlation between the CTCs and the expression of CSCs, both were positively correlated with metastasis and poor prognosis. These results indicated that the CTCs might indirectly reflect the expression of CSCs.

Mating-driven variability in olfactory local interneuron wiring.

Variations in neuronal connectivity occur widely in nervous systems from invertebrates to mammals. Yet, it is unclear how neuronal variability originates, to what extent and at what time scales it exists, and what functional consequences it might carry. To assess inter- and intraindividual neuronal variability, it would be ideal to analyze the same identified neuron across different brain hemispheres and individuals. Here, using genetic labeling and electron microscopy connectomics, we show that an identified inhibitory olfactory local interneuron, TC-LN, exhibits extraordinary variability in its glomerular innervation patterns. Moreover, TC-LN's innervation of the VL2a glomerulus, which processes food signals and modulates mating behavior, is sexually dimorphic, is influenced by female's courtship experience, and correlates with food intake in mated females. Mating also affects output connectivity of TC-LN to specific local interneurons. We propose that mating-associated variability of TC-LNs regulates how food odor is interpreted by an inhibitory network to modulate feeding.

Mutant p53 Attenuates Oxidative Phosphorylation and Facilitates Cancer Stemness through Downregulating miR-200c-PCK2 Axis in Basal-Like Breast Cancer.

miR-200c is a tumor suppressor miRNA that plays a critical role in regulating epithelial phenotype and cancer stemness. p53 deficiency downregulates the expression of miR-200c and leads to epithelial-mesenchymal transition (EMT) and stemness phenotype, which contributes to the progression of breast cancers. In this study, we demonstrated that CRISPR-mediated knockout (KO) of miR-200c induces metabolic features similar to the metabolic rewiring caused by p53 hot-spot mutations, and that impairing this metabolic reprogramming interferes with miR-200c deficiency-induced stemness and transformation. Moreover, restoring miR-200c expression compromised EMT, stem-cell properties, and the Warburg effect caused by p53 mutations, suggesting that mutant p53 (MTp53) induces EMT-associated phenotypes and metabolic reprogramming by downregulating miR-200c. Mechanistically, decreased expression of PCK2 was observed in miR-200c- and p53-deficient mammary epithelial cells, and forced expression of miR-200c restored PCK2 in p53 mutant-expressing cells. Reduced PCK2 expression not only led to attenuated oxidative phosphorylation (OXPHOS) and increased stemness in normal mammary epithelial cells but also compromised the enhanced OXPHOS and suppression of cancer stemness exerted by miR-200c in p53 mutation-bearing basal-like breast cancer (BLBC) cells. Clinically, PCK2 expression is negatively associated with EMT markers and is downregulated in basal-like subtype and cases with low miR-200c expression or p53 mutation. Notably, low expression of PCK2 is associated with poor overall survival (OS) in patients with breast cancer. IMPLICATIONS: Together, our results suggest that p53 and miR-200c regulate OXPHOS and stem/cancer stemness through PCK2, and loss of the p53-miR-200c-PCK2 axis might provide metabolic advantages that facilitate cancer stemness, leading to the progression of BLBCs.