Shear stress activates ATOH8 via autocrine VEGF promoting glycolysis dependent-survival of colorectal cancer cells in the circulation.

BACKGROUND: Metastasis and recurrence, wherein circulating tumour cells (CTCs) play an important role, are the leading causes of death in colorectal cancer (CRC). Metastasis-initiating CTCs manage to maintain intravascular survival under anoikis, immune attack, and importantly shear stress; however, the underlying mechanisms remain poorly understood. METHODS: In view of the scarcity of CTCs in the bloodstream, suspended colorectal cancer cells were flowed into the cyclic laminar shear stress (LSS) according to previous studies. Then, we detected these suspended cells with a CK8+/CD45-/DAPI+ phenotype and named them mimic circulating tumour cells (m-CTCs) for subsequent CTCs related researches. Quantitative polymerase chain reaction, western blotting, and immunofluorescence were utilised to analyse gene expression change of m-CTCs sensitive to LSS stimulation. Additionally, we examined atonal bHLH transcription factor 8 (ATOH8) expressions in CTCs among 156 CRC patients and mice by fluorescence in situ hybridisation and flow cytometry. The pro-metabolic and pro-survival functions of ATOH8 were determined by glycolysis assay, live/dead cell vitality assay, anoikis assay, and immunohistochemistry. Further, the concrete up-and-down mechanisms of m-CTC survival promotion by ATOH8 were explored. RESULTS: The m-CTCs actively responded to LSS by triggering the expression of ATOH8, a fluid mechanosensor, with executive roles in intravascular survival and metabolism plasticity. Specifically, ATOH8 was upregulated via activation of VEGFR2/AKT signalling pathway mediated by LSS induced VEGF release. ATOH8 then transcriptionally activated HK2-mediated glycolysis, thus promoting the intravascular survival of colorectal cancer cells in the circulation. CONCLUSIONS: This study elucidates a novel mechanism that an LSS triggered VEGF-VEGFR2-AKT-ATOH8 signal axis mediates m-CTCs survival, thus providing a potential target for the prevention and treatment of hematogenous metastasis in CRC.

Adipocytes fuel gastric cancer omental metastasis via PITPNC1-mediated fatty acid metabolic reprogramming.

Omental metastasis occurs frequently in gastric cancer (GC) and is considered one of the major causes of gastric cancer-related mortality. Recent research indicated that omental adipocytes might mediate this metastatic predilection. Phosphatidylinositol transfer protein, cytoplasmic 1 (PITPNC1) was identified to have a crucial role in metastasis. However, whether PITPNC1 participates in the interaction between adipocytes and GC omental metastasis is unclear. Methods: We profiled and analyzed the expression of PITPNC1 through analysis of the TCGA database as well as immunohistochemistry staining using matched GC tissues, adjacent normal gastric mucosa tissues (ANTs), and omental metastatic tissues. The regulation of PITPNC1 by adipocytes was explored by co-culture systems. By using both PITPNC1 overexpression and silencing methods, the role of PITPNC1 in anoikis resistance and metastasis was determined through in vitro and in vivo experiments. Results: PITPNC1 was expressed at higher rates in GC tissues than in ANTs; notably, it was higher in omental metastatic lesions. Elevated expression of PITPNC1 predicted higher rates of omental metastasis and a poor prognosis. PITPNC1 promoted anoikis resistance through fatty acid metabolism by upregulating CD36 and CPT1B expression. Further, PITPNC1 was elevated by adipocytes and facilitated GC omental metastasis. Lastly, in vivo studies showed that PITPNC1 was a therapeutic indicator of fatty acid oxidation (FAO) inhibition. Conclusion: Elevated expression of PITPNC1 in GC is correlated with an advanced clinical stage and a poor prognosis. PITPNC1 promotes anoikis resistance through enhanced FAO, which is regulated by omental adipocytes and consequently facilitates GC omental metastasis. Targeting PITPNC1 might present a promising strategy to treat omental metastasis.

IMAGING OF BRAIN FUNCTION BASED ON THE ANALYSIS OF FUNCTIONAL CONNECTIVITY - IMAGING ANALYSIS OF BRAIN FUNCTION BY FMRI AFTER ACUPUNCTURE AT LR3 IN HEALTHY INDIVIDUALS.

OBJECTIVE: This Study observed the relevant brain areas activated by acupuncture at the Taichong acupoint (LR3) and analyzed the functional connectivity among brain areas using resting state functional magnetic resonance imaging (fMRI) to explore the acupoint specificity of the Taichong acupoint. METHODS: A total of 45 healthy subjects were randomly divided into the Taichong (LR3) group, sham acupuncture group and sham acupoint group. Subjects received resting state fMRI before acupuncture, after true (sham) acupuncture in each group. Analysis of changes in connectivity among the brain areas was performed using the brain functional connectivity method. RESULTS: The right cerebrum temporal lobe was selected as the seed point to analyze the functional connectivity. It had a functional connectivity with right cerebrum superior frontal gyrus, limbic lobe cingulate gyrus and left cerebrum inferior temporal gyrus (BA 37), inferior parietal lobule compared by before vs. after acupuncture at LR3, and right cerebrum sub-lobar insula and left cerebrum middle frontal gyrus, medial frontal gyrus compared by true vs. sham acupuncture at LR3, and right cerebrum occipital lobe cuneus, occipital lobe sub-gyral, parietal lobe precuneus and left cerebellum anterior lobe culmen by acupuncture at LR3 vs. sham acupoint. CONCLUSION: Acupuncture at LR3 mainly specifically activated the brain functional network that participates in visual function, associative function, and emotion cognition, which are similar to the features on LR3 in tradition Chinese medicine. These brain areas constituted a neural network structure with specific functions that had specific reference values for the interpretation of the acupoint specificity of the Taichong acupoint.