Biology subjects

Niu, N.

Publications and source records attributed to Niu, N..

4 recordsLinked to original sources

bioRxiv2023

Multilevel regulation of NF-kappa B signaling by NSD2 suppresses Kras-driven pancreatic tumorigenesis

Pancreatic ductal adenocarcinoma (PDAC) is a clinically challenging cancer with a dismal overall prognosis. NSD2 is an H3K36-specific di-methyltransferase which has been reported to play a crucial role in promoting tumorigenesis. Here, we demonstrate that NSD2 acts as a putative tumor suppressor in Kras-driven pancreatic tumorigenesis. Low level of NSD2 indicates aggressive feature of PDAC. NSD2 restrains the mice from inflammation and Kras-induced ductal metaplasia, while NSD2 loss facilitates pancreatic tumorigenesis. Mechanistically, NSD2-mediated H3K36me2 promotes the expression of I{kappa}B, which inhibits the phosphorylation of p65 and NF-{kappa}B nuclear translocation. More importantly, NSD2 interacts with the DNA binding domain of p65, attenuating NF-{kappa}B transcriptional activity. Furthermore, inhibition of NF-{kappa}B signaling relieves the symptoms of Nsd2-deficient mice. Together, our study reveals the important tumor suppressor role of NSD2 and multiple mechanisms by which NSD2 suppresses both p65 phosphorylation and downstream transcriptional activity during pancreatic tumorigenesis. This study contributes to understanding the pathogenesis of pancreatic tumorigenesis and identifies a novel negative regulator of NF-{kappa}B signaling.

cancer biology↗

bioRxiv2023

Modeling, dissecting, and subtyping of E-Cadherin inactivation-associated diffuse-type gastric adenocarcinoma

This study investigates diffuse-type gastric adenocarcinoma (DGAC), a deadly and treatment-resistant cancer. It reveals that CDH1 inactivation occurs in a subset of DGAC patient tumors, leading to the identification of two distinct DGAC subtypes. The findings emphasize the importance of understanding DGACs molecular diversity for personalized medicine in patients with CDH1 inactivation.

cancer biology↗

bioRxiv2022

Dalpiciclib Partially Abrogates ER Signaling Activation Induced by Pyrotinib In HER2+HR+ Breast Cancer

BackgroundRecent evidences from clinical trials (NCT04486911) revealed that the combination of pyrotinib, letrozole and dalpiciclib exerted optimistic therapeutic effect to treat HER2+HR+ breast cancer, however, the underlying molecular mechanism remained further investigation. MethodsThrough the drug sensitivity test, the drug combination efficacy of pyrotinib, tamoxifen and dalpiciclib to BT474 cells were tested. The underlying molecular mechanisms were investigated using immunofluorescence, western blot analysis, immunohistochemical staining and cell cycle analysis. Potential risk factor which may indicate the responsiveness to drug treatment in HER2+/HR+ breast cancer was selected out using RNA-sequence and tested using immunohistochemical staining and in vivo drug susceptibility test. ResultsWe found that pyrotinib combined with dalpiciclib exerted better cytotoxic efficacy than pyrotinib combined with tamoxifen in BT474 cells. Degradation of HER2 could enhance ER nuclear transportation, activating ER signaling pathway in BT474 cells whereas dalpiciclib could partially abrogate this process. This may be the underlying mechanism by which combination of pyrotinib, tamoxifen and dalpiciclib exerted best cytotoxic effect. Furthermore, CALML5 was revealed to be a risk factor in the treatment of HER2+/HR+ breast cancer and the usage of dalpiciclib might overcome this. ConclusionOur study provided evidence that the usage of dalpiciclib in the treatment of HER2+/HR+ breast cancer could partially abrogate the estrogen signaling pathway activation caused by anti-HER2 therapy and revealed that CALML5 could serve as a risk factor in the treatment of HER2+/HR+ breast cancer. FundingThis study was supported by the National Natural Science Foundation of China (#U20A20381, #81872159)

cancer biology↗

bioRxiv2021

Dalpiciclib and Pyrotinib Exert Synergistic Antitumor Effects in Triple Positive Breast Cancer

BackgroundThe therapeutic benefit of the standard combination of anti-HER2 and chemotherapy in triple-positive breast cancer (TPBC) is limited even after the addition of endocrine therapy to the regimen. Therefore, treatment optimization is required urgently. MethodsThrough the drug sensitivity test, the drug combination efficacy of anti-HER2 drug, endocrine drug and CDK4/6 inhibitor to BT474 cells were tested. The underlying molecular mechanisms were investigated using immunofluorescence, western blot analysis, immunohistochemical staining and cell cycle analysis. Potential biomarker which may indicate the responsiveness to drug treatment in triple positive breast cancer was selected out using RNA-sequence and tested using immunohistochemical staining. ResultsWe found that pyrotinib combined with dalpiciclib showed better efficacy than pyrotinib combined with tamoxifen in BT474 cells. Degradation of HER2 could enhance ER nuclear transportation, whereas cell cycle blockers could reverse this process. This may be the underlying mechanism by which the addition of dalpiciclib was more beneficial than the addition of pyrotinib plus tamoxifen. Furthermore, CALML5 was revealed to be a potential indicator of responsiveness to anti-HER2 therapy plus CDK4/6 inhibition in triple positive breast cancer. ConclusionOur study provided evidence for the introduction of CDK4/6 inhibitor in the treatment of TPBC and indicated that the combination of anti-HER2 therapy and cell cycle blockers may be a better strategy for TPBC treatment. FundingThis study was supported by the National Natural Science Foundation of China (#U20A20381, #81872159)

cell biology↗