Involucrasin B Inhibits the Proliferation of Caco-2 Cells by Regulating the TGFß/SMAD2-3-4 Pathway.

(1) Background: Colorectal cancer (CRC) is the third most common malignant tumor worldwide and the second most common cause of cancer death. However, effective anti-CRC drugs are still lacking in clinical settings. This article investigated the anti-proliferative effect of involucrasin B on CRC Caco-2 cells. (2) Methods: This study employed a sulforhodamine B (SRB) method, colony formation experiments, flow cytometry, FastFUCCI assay, dual luciferase assay, and Western blot analysis for the investigation. (3) Results: The SRB method and colony formation experiments showed that involucrasin B exhibited an inhibitory effect on the Caco-2 cells cultured in vitro. Subsequently, the flow cytometry, FastFUCCI assay, and Western blotting results showed that involucrasin B induced cell cycle arrest in the G1 phase dose-dependently. Involucrasin B significantly enhanced the TGFß RII protein level and SMAD3 phosphorylation, thus inhibiting the expression of CDK4 and cyclin D1 and causing G1 cell cycle arrest. (4) Conclusion: This study shows that involucrasin B exerts its anti-proliferative effect by regulating the TGFß/SMAD2-3-4 pathway to cause G1 cycle arrest in Caco-2 cells.

Rhinovirus Suppresses TGF-ß-GARP Presentation by Peripheral NK Cells.

Asthma is a chronic airway disease whose exacerbations are often triggered by rhinovirus infection. TGF-ß1 induces rhinovirus replication in infected cells. Moreover, TGF-ß1 is a pleiotropic mediator that is produced by many immune cells in the latent, inactive form bound to the latency-associated peptide (LAP) and to the transmembrane protein glycoprotein A repetitions predominant (GARP). In this study we wanted to investigate the effect of rhinovirus infection on the TGF-ß secretion and the downstream signaling via TGF-ßRI/RII in peripheral blood mononuclear cells from control and asthmatic patients after rhinovirus infection ex vivo. Here, we found a significant upregulation of TGF-ßRII in untouched PBMCs of asthmatics as well as a suppression of TGF-ß release in the rhinovirus-infected PBMC condition. Moreover, consistent with an effect of TGF-ß on Tregs, PBMCs infected with RV induced Tregs, and TGF-ßRII directly correlated with RV1b mRNA. Finally, we found via flow cytometry that NK cells expressed less GARP surface-bound TGF-ß, while cytokine-producing NKbright cells were induced. In summary, we show that rhinovirus infection inhibits TGF-ß release in PBMCs, which results in the activation of both Treg and NK cells.

Gene Silencing of TGFßRII Can Inhibit Glioblastoma Cell Growth

Objective: Glioblastoma (GBM) is the most malignant and aggressive type of glioma, associated with a high rate of mortality. The transforming growth factor-ß receptor II (TGFß RII) is involved in glioma initiation and progression. On the other hand, TGFß RII silencing is critical to the inhibition of GBM. Therefore, we aimed to determine the effects of specific TGFß RII siRNA on the survival of U-373MG cells. Methods: TGFß RII siRNA was transfected, and qRT-PCR was performed to examine TGFß RII mRNA expression. Cell survival was determined using colorimetric MTT assay, and platelet-derived growth factor-BB (PDGF-BB) level was measured in the culture supernatant using ELISA assay. Result: Our findings indicated that specific siRNAs could dose-dependently suppress TGFß RII mRNA expression after 48 hours. In addition, treatment with TGFß RII siRNA significantly reduced tumor cell survival and decreased the amount of PDGF-BB protein in the cell culture supernatant. Conclusion: Our results suggest that TGFß RII silencing can be a promising complementary treatment for glioma.