MYPT1, regulated by miR-19b-3p inhibits the progression of non-small cell lung cancer via inhibiting the activation of wnt/β-catenin signaling

Wnt/β-catenin signaling in the development and therapeutic resistance of non-small cell lung cancer

Wnt/β-catenin signaling is a critical pathway that influences development and therapeutic response of non-small cell lung cancer (NSCLC). In recent years, many Wnt regulators, including proteins, miRNAs, lncRNAs, and circRNAs, have been found to promote or inhibit signaling by acting on Wnt proteins, receptors, signal transducers and transcriptional effectors. The identification of these regulators and their underlying molecular mechanisms provides important implications for how to target this pathway therapeutically. In this review, we summarize recent studies of Wnt regulators in the development and therapeutic response of NSCLC.

Myosin phosphatase targeting subunit1 controls localization and motility of Rab7-containing vesicles: Is myosin phosphatase a cytoplasmic dynein regulator?

Myosin phosphatase targeting subunit1 (MYPT1) is a critical subunit of myosin phosphatase (MP), which brings PP1Cδ phosphatase and its substrate together. We previously showed that MYPT1 depletion resulted in oblique chromatid segregation. Therefore, we hypothesized that MYPT1 may control microtubule-dependent motor activity. Dynein, a minus-end microtubule motor, is known to be involved in mitotic spindle assembly. We thus examined whether MYPT1 and dynein may interact. Proximity ligation assay and co-immunoprecipitation revealed that MYPT1 and dynein intermediate chain (DIC) were associated. We found that DIC phosphorylation is increased in MYPT1-depleted cells in vivo, and that MP was able to dephosphorylate DIC in vitro. MYPT1 depletion also altered the localization and motility of Rab7-containing vesicles. MYPT1-depletion dispersed the perinuclear Rab7 localization to the peripheral in interphase cells. The dispersed Rab7 localization was rescued by microinjection of a constitutively active, truncated MYPT1 mutant, supporting that MP is responsible for the altered Rab7 localization. Analyses of Rab7 vesicle trafficking also revealed that minus-end transport was reduced in MYPT1-depleted cells. These results suggest an unexpected role of MP: MP controls dynein activity in both mitotic and interphase cells, possibly by dephosphorylating dynein subunits including DIC.

FAT10 differentially stabilizes MYPT2 isoforms

Myosin phosphatase (MP) is an enzyme complex that regulates muscle contraction and plays important roles in various physiological and pathological conditions. Myosin phosphatase targeting subunit (MYPT) 2, a subunit of MP, interacts with protein phosphatase 1c to regulate its phosphatase activity. MYPT2 exists in various isoforms that differ in the composition of essential motifs that contribute to its function. However, regulatory mechanisms underlying these isoforms are poorly understood. Human leukocyte antigen-F adjacent transcript 10 (FAT10) is a ubiquitin-like modifier that not only targets proteins for proteasomal degradation but also stabilizes its interacting proteins. In this study, we investigated the effect of the interaction between FAT10 and MYPT2 isoform a (the canonical full-length form of MYPT2) or MYPT2 isoform f (the natural truncated form of MYPT2). FAT10 interacted with both MYPT2 isoforms a and f; however, only MYPT2 isoform f was increased by FAT10, whereas MYPT2 isoform a remained unaffected by FAT10. We further confirmed that, in contrast to MYPT2 isoform a, MYPT2 isoform f undergoes rapid degradation via the ubiquitin-proteasome pathway and that FAT10 stabilizes MYPT2 isoform f by inhibiting its ubiquitination. Therefore, our findings suggest that the interaction between FAT10 and MYPT2 isoforms leads to distinct stabilization effects on each isoform, potentially modulating MP activity.

Optimization of Neferine Purification Based on Response Surface Methodology and Its Anti-Metastasis Mechanism on HepG2 Cells

Liver cancer continues to be a focus of scientific research due to its low five-year survival rate. One of its main core issues is the high metastasis of cells, for which there is no effective treatment. Neferine was originally isolated from Plumula nelumbinis and demonstrated to have a good antitumor effect. In order to extract high-purity Neferine in a more efficient and environmentally friendly manner, response surface methodology (RSM) was used to optimize the isolation and purification procedures in this study. The extract conditions of a 7:3 ratio for the eluent of dichloromethane: methanol, 1:60 for the mass ratio of the extract amount: silica gel, and 3 mL/min of the elution flow rate were shown to be the optimal conditions. These conditions resulted in the highest yield of 6.13 mg per 66.60 mg of starting material, with productivity of 8.76% and purity of 87.04%. Compared with the previous methods, this method can prepare Neferine in large quantities more quickly. We subsequently evaluated the antitumor activity of the purified Neferine against HepG2 hepatic cancer cells. The purified Neferine was found to inhibit the proliferation of HepG2 cells through the CCK-8 assay, with an IC₅₀ of 33.80 μM in 24 h, 29.47 μM in 48 h, 24.35 μM in 72 h and 2.78 μM in 96 h of treatment. Neferine at a concentration of 3 μM could significantly inhibit the migration and invasion abilities of the HepG2 cells in vitro. We also explored the mechanism of action of Neferine via Western blot. We showed that Neferine could reduce RhoA expression by effectively inhibiting the phosphorylation of MYPT1, thereby effectively exerting anti-metastasis activity against HepG2 cells. Thus, we have optimized the isolation procedures for highly pure Neferine by response surface methodology (RSM) in this study, and purified Neferine is shown to play an essential role in the anti-metastasis process of liver cancer cells. The Neferine purification procedure may make a wide contribution to the follow-up development of other anti-metastasis lead compounds.

miR‑29a‑3p inhibits the malignant characteristics of non‑small cell lung cancer cells by reducing the activity of the Wnt/β‑catenin signaling pathway

MicroRNAs (miRNAs) can influence non-small cell lung cancer (NSCLC) in a tumor-suppressive and oncogenic manner. The present study aimed to investigate the effects and underlying mechanisms of miR-29a-3p in NSCLC. NSCLC cell lines (A549, H1299, and H460) and a normal lung epithelial cell line (BEAS-2B) were used. Additionally, a mouse lung tumor xenograft model was established using A549 cells and used to determine the effects of miR-29a-3p on NSCLC in vivo. Tumor volumes were measured every week. The expression of miR-29a-3p in cells and lung tissues were detected by RT-qPCR. Cell proliferation was detected using Cell Counting Kit-8 and EdU assays. Migration and invasion were assessed using wound healing and Transwell invasion assays, respectively. Ki-67 expression was detected using immunohistochemical staining. The expression levels of Wnt3a and β-catenin were determined using western blotting. miR-29a-3p expression was significantly downregulated in NSCLC cells and mice. In contrast to miR-29a-3p knockdown, miR-29a-3p overexpression decreased NSCLC cell proliferation, migration, and invasion as well as tumor growth in in the NSCLC mouse model. Moreover, miR-29a-3p overexpression decreased the protein expression levels of Wnt3a and β-catenin. The inhibitory effects of miR-29a-3p on NSCLC cells were reversed by LiCl (an activator of the Wnt signaling pathway). In conclusion, miR-29a-3p prevented NSCLC tumor growth and cell proliferation, migration, and invasion by inhibiting the Wnt/β-catenin signaling pathway. This finding offers novel insights into the prognosis and treatment of NSCLC.

Ferulic Acid Combined With Bone Marrow Mesenchymal Stem Cells Attenuates the Activation of Hepatic Stellate Cells and Alleviates Liver Fibrosis

Bone marrow mesenchymal stem cells (BMSCs) can effectively alleviate liver fibrosis, but the efficacy of cell therapy alone is insufficient. In recent years, a combination of traditional Chinese medicine (TCM) and cell therapy has been increasingly used to treat diseases in clinical trials. Ferulic acid (FA) is highly effective in treating liver fibrosis, and a combination of cells and drugs is being tested in clinical trials. Therefore, we combined BMSCs and Ferulic acid to treat CCl₄-induced fibrosis and determine whether this combination was more effective than single treatment. We used BMSCs and FA to treat CCl₄-induced fibrosis in rat models, observed their therapeutic effects, and investigated the specific mechanism of this combination therapy in liver fibrosis. We created a BMSC/hepatic stellate cell (HSC) coculture system and used FA to treat activated HSCs to verify the specific mechanism. Then, we used cytochalasin D and angiotensin II to investigate whether BMSCs and FA inactivate HSCs through cytoskeletal rearrangement. MiR-19b-3p was enriched in BMSCs and targeted TGF-β receptor II (TGF-βR2). We separately transfected miR-19b-3p into HSCs and BMSCs and detected hepatic stellate cell activation. We found that the expression of the profibrotic markers α-SMA and COL1-A1 was significantly decreased in the combination group of rats. α-SMA and COL1-A1 levels were also significantly decreased in the HSCs with the combination treatment. Cytoskeletal rearrangement of HSCs was inhibited in the combination group, and RhoA/ROCK pathway gene expression was decreased. Following angiotensin II treatment, COL1-A1 and α-SMA expression increased, while with cytochalasin D treatment, profibrotic gene expression decreased in HSCs. The expression of COL1-A1, α-SMA and RhoA/ROCK pathway genes was decreased in the activated HSCs treated with a miR-19b-3p mimic, indicating that miR-19b-3p inactivated HSCs by suppressing RhoA/ROCK signalling. In contrast, profibrotic gene expression was significantly decreased in the BMSCs treated with the miR-19b-3p mimic and FA or a miR-19b-3p inhibitor and FA compared with the BMSCs treated with the miR-19b-3p mimic alone. In conclusion, the combination therapy had better effects than FA or BMSCs alone. BMSC and FA treatment attenuated HSC activation and liver fibrosis by inhibiting cytoskeletal rearrangement and delivering miR-19b-3p to activated HSCs, inactivating RhoA/ROCK signalling. FA-based combination therapy showed better inhibitory effects on HSC activation.

MicroRNA miR-19b-3p mediated G protein γ subunit 7 (GNG7) loss contributes lung adenocarcinoma progression through activating Hedgehog signaling

G protein γ subunit 7 (GNG7) is a subunit of heterotrimeric G protein. It has been demonstrated low expressed GNG7 in various cancers. Nevertheless, the role of GNG7 in lung adenocarcinoma (LUAD) remains unclear. In the present study, GNG7 expression in LUAD tissues and cell lines was analyzed by RT-qPCR, western blot and immunohistochemical. Kaplan–Meier analysis was performed for determining the prognostic value of GNG7 expression. Then, the function of GNG7 in LUAD progression was examined by cell proliferation, invasion and mouse xenograft assays. In addition, the underlying biological mechanisms of GNG7 in LUAD progression were explored via the bioinformatics analysis and experimental validation. We found GNG7 was markedly down-regulated in LUAD tissues and cell lines. Clinically, low expression of GNG7 was associated with the dismal prognosis of LUAD patients. Gain-of-function analysis showed that GNG7 overexpression inhibited proliferation and invasion of LUAD cell in vitro, and compromised tumor formation ability in vivo. Besides, mechanistic study revealed that overexpression of GNG7 affected the progression of LUAD via inhibiting activation of Hedgehog signaling. Moreover, bioinformatics prediction and experimental verification confirmed that GNG7 was targeted by miR-19b-3p, which was elevated expression in LUAD and promoting the progression of LUAD. Furthermore, rescue experiments demonstrated that GNG7 reintroduction weakened miR-19b-3p-mediated aggressive tumor phenotypes of LUAD cells. These findings suggested miR-19b-3p/GNG7 axis contributed to the progression of LUAD through Hedgehog signaling, which might be a potential therapeutic target for LUAD treatment.