Conditioned mesenchymal stem cells attenuate progression of chronic kidney disease through inhibition of epithelial‐to‐mesenchymal transition and immune modulation

Mesenchymal stem cells (MSCs) have been shown to improve the outcome of acute renal injury models; but whether MSCs can delay renal failure in chronic kidney disease (CKD) remains unclear. In the present study, the were cultured in media containing various concentrations of basic fibroblast growth factor, epidermal growth factor and ascorbic acid 2‐phosphate to investigate whether hepatocyte growth factor (HGF) secretion could be increased by the stimulation of these growth factors. Then, TGF‐β1‐treated renal interstitial fibroblast (NRK‐49F), renal proximal tubular cells (NRK‐52E) and podocytes were co‐cultured with conditioned MSCs in the absence or presence of ascorbic acid 2‐phosphate to quantify the protective effects of conditioned MSCs on renal cells. Moreover, male Sprague‐Dawley rats were treated with 1 × 10⁶ conditioned MSCs immediately after 5/6 nephrectomy and every other week through the tail vein for 14 weeks. It was found that basic fibroblast growth factor, epidermal growth factor and ascorbic acid 2‐phosphate promoted HGF secretion in MSCs. Besides, conditioned MSCs were found to be protective against TGF‐β1 induced epithelial‐to‐mesenchymal transition of NRK‐52E and activation of NRK‐49F cells. Furthermore, conditioned MSCs protected podocytes from TGF‐β1‐induced loss of synaptopodin, fibronectin induction, cell death and apoptosis. Rats transplanted with conditioned human MSCs had a significantly increase in creatinine clearance rate, decrease in glomerulosclerosis, interstitial fibrosis and increase in CD4⁺CD25⁺Foxp3⁺ regulatory T cells counts in splenocytes. Together, our studies indicated that conditioned MSCs preserve renal function by their anti‐fibrotic and anti‐inflammatory effects. Transplantation of conditioned MSCs may be useful in treating CKD.     

Mesenchymal stem cells promote cell invasion and migration and autophagy‐induced epithelial‐mesenchymal transition in A549 lung adenocarcinoma cells

Mesenchymal stem cells (MSCs) are recruited into the tumour microenvironment and promote tumour growth and metastasis. Tumour microenvironment‐induced autophagy is considered to suppress primary tumour formation by impairing migration and invasion. Whether these recruited MSCs regulate tumour autophagy and whether autophagy affects tumour growth are controversial. Our data showed that MSCs promote autophagy activation, reactive oxygen species production, and epithelial‐mesenchymal transition (EMT) as well as increased migration and invasion in A549 cells. Decreased expression of E‐cadherin and increased expression of vimentin and Snail were observed in A549 cells cocultured with MSCs. Conversely, MSC coculture‐mediated autophagy positively promoted tumour EMT. Autophagy inhibition suppressed MSC coculture‐mediated EMT and reduced A549 cell migration and invasion slightly. Furthermore, the migratory and invasive abilities of A549 cells were additional increased when autophagy was further enhanced by rapamycin treatment. Taken together, this work suggests that microenvironments containing MSCs can promote autophagy activation for enhancing EMT; MSCs also increase the migratory and invasive abilities of A549 lung adenocarcinoma cells. Mesenchymal stem cell‐containing microenvironments and MSC‐induced autophagy signalling may be potential targets for blocking lung cancer cell migration and invasion.     

LncRNA HOTAIR/miR‐613/c‐met axis modulated epithelial‐mesenchymal transition of retinoblastoma cells

Since lncRNAs could modulate neoplastic development by modulating downstream miRNAs and genes, this study was carried out to figure out the synthetic contribution of HOTAIR, miR‐613 and c‐met to viability, apoptosis and proliferation of retinoblastoma cells. Totally 276 retinoblastoma tissues and tumour‐adjacent tissues were collected, and human retinoblastoma cell lines (ie, Y79, HXO‐Rb44, SO‐Rb50 and WERI‐RB1) were also gathered. Moreover, transfections of pcDNA3.1‐HOTAIR, si‐HOTAIR, miR‐613 mimic, miR‐613 inhibitor, pcDNA3.1/c‐met were performed to evaluate the influence of HOTAIR, miR‐613 and c‐met on viability, apoptosis and epithelial‐mesenchymal transition (EMT) of retinoblastoma cells. Dual‐luciferase reporter gene assay was also arranged to confirm the targeted relationship between HOTAIR and miR‐613, as well as between miR‐613 and c‐met. Consequently, up‐regulated HOTAIR and down‐regulated miR‐613 expressions displayed associations with poor survival status of retinoblastoma patients (P < 0.05). Besides, inhibited HOTAIR and promoted miR‐613 elevated E‐cadherin expression, yet decreased Snail and Vimentin expressions (P < 0.05). Simultaneously, cell proliferation and cell viability were also less‐motivated (P < 0.05). Nonetheless, c‐met prohibited the functioning of miR‐613, resulting in promoted cell proliferation and viability, along with inhibited cell apoptosis (P < 0.05). Finally, HOTAIR was verified to directly target miR‐613, and c‐met was the direct target gene of miR‐613 (P < 0.05). In conclusion, the role of lncRNA HOTAIR/miR‐613/c‐met signalling axis in modulating retinoblastoma cells’ viability, apoptosis and expressions of EMT‐specific proteins might provide evidences for developing appropriate diagnostic and treatment strategies for retinoblastoma.     

miR‐655 suppresses epithelial‐to‐mesenchymal transition by targeting Prrx1 in triple‐negative breast cancer

Triple‐negative breast cancer (TNBC) is a highly aggressive breast cancer subtype that lacks effective targeted therapies. The epithelial‐to‐mesenchymal transition (EMT) is a key contributor in the metastatic process. In this study, we found that miR‐655 was down‐regulated in TNBC, and its expression levels were associated with molecular‐based classification and lymph node metastasis in breast cancer. These findings led us to hypothesize that miR‐655 overexpression may inhibit EMT and its associated traits of TNBC. Ectopic expression of miR‐655 not only induced the up‐regulation of cytokeratin and decreased vimentin expression but also suppressed migration and invasion of mesenchymal‐like cancer cells accompanied by a morphological shift towards the epithelial phenotype. In addition, we found that miR‐655 was negatively correlated with Prrx1 in cell lines and clinical samples. Overexpression of miR‐655 significantly suppressed Prrx1, as demonstrated by Prrx1 3′‐untranslated region luciferase report assay. Our study demonstrated that miR‐655 inhibits the acquisition of the EMT phenotype in TNBC by down‐regulating Prrx1, thereby inhibiting cell migration and invasion during cancer progression.     

Astragaloside IV modulates TGF‐β1‐dependent epithelial‐mesenchymal transition in bleomycin‐induced pulmonary fibrosis

Epithelial‐mesenchymal transition (EMT) plays an important role in idiopathic pulmonary fibrosis (IPF). Astragaloside IV (ASV), a natural saponin from astragalus membranaceus, has shown anti‐fibrotic property in bleomycin (BLM)‐induced pulmonary fibrosis. The current study was undertaken to determine whether EMT was involved in the beneficial of ASV against BLM‐induced pulmonary fibrosis and to elucidate its potential mechanism. As expected, in BLM‐induced IPF, ASV exerted protective effects on pulmonary fibrosis and ASV significantly reversed BLM‐induced EMT. Intriguing, transforming growth factor‐β1 (TGF‐β1) was found to be up‐regulated, whereas Forkhead box O3a (FOXO3a) was hyperphosphorylated and less expressed. However, ASV treatment inhibited increased TGF‐β1 and activated FOXO3a in lung tissues. TGF‐β1 was administered to alveolar epithelial cells A549 to induce EMT in vitro. Meanwhile, stimulation with TGF‐β1‐activated phosphatidylinositol 3 kinase/protein kinase B (PI3K/Akt) pathway and induced FOXO3a hyperphosphorylated and down‐regulated. It was found that overexpression of FOXO3a leading to the suppression of TGF‐β1‐induced EMT. Moreover, ASV treatment, similar with the TGF‐β1 or PI3K/Akt inhibitor, reverted these cellular changes and inhibited EMT in A549 cells. Collectively, the results suggested that ASV significantly inhibited TGF‐β1/PI3K/Akt‐induced FOXO3a hyperphosphorylation and down‐regulation to reverse EMT during the progression of fibrosis.     

The CCN1 (CYR61) protein promotes skin growth by enhancing epithelial‐mesenchymal transition during skin expansion

The skin expansion technique is widely used to induce skin growth for large‐scale skin deformity reconstruction. However, the capacity for skin expansion is limited and searching for ways to improve the expansion efficiency is a challenge. In this study, we aimed to explore the possible mechanism of skin expansion and to find a potential therapeutic target on promoting skin growth. We conducted weighted gene coexpression network analysis (WGCNA) of microarray data generated from rat skin expansion and found CCN1 (CYR61) to be the central hub gene related to epithelial‐mesenchymal transition (EMT). CCN1 up‐regulation was confirmed in human and rat expanded skin and also in mechanically stretched rat keratinocytes, together with acquired mesenchymal phenotype. After CCN1 stimulation on keratinocytes, cell proliferation was promoted and partial EMT was induced by activating β‐catenin pathway. Treatment of CCN1 protein could significantly increase the flap thickness, improve the blood supply and restore the structure in a rat model of skin expansion, whereas inhibition of CCN1 through shRNA interference could dramatically reduce the efficiency of skin expansion. Our findings demonstrate that CCN1 plays a crucial role in skin expansion and that CCN1 may serve as a potential therapeutic target to promote skin growth and improve the efficiency of skin expansion.     

A‐kinase‐interacting protein 1 facilitates growth and metastasis of gastric cancer cells via Slug‐induced epithelial‐mesenchymal transition

A‐kinase‐interacting protein 1 (AKIP1) has previously been reported to act as a potential oncogenic protein in various cancers. The clinical significance and biological role of AKIP1 in gastric cancer (GC) is, however, still elusive. Herein, this study aimed to investigate the functional and molecular mechanism by which AKIP1 influences GC. AKIP1 mRNA and protein expressions in GC tissues were examined by quantitative real‐time PCR (qRT‐PCR), Western blot and immunohistochemistry. Other methods including stably transfected against AKIP1 into gastric cancer cells, wound healing, transwell assays, CCK‐8, colony formation, qRT‐PCR and Western blot in vitro and tumorigenesis in vivo were also performed. The up‐regulated expression of AKIP1 in GC specimens significantly correlated with clinical metastasis and poor prognosis in patients with GC. AKIP1 knockdown markedly suppressed GC cells proliferation, invasion and metastasis both in vitro and in vivo. In contrast, AKIP1 overexpression resulted in the opposite effects. Moreover, mechanistic analyses indicated that Slug‐induced epithelial‐mesenchymal transition (EMT) might be responsible for AKIP1‐influenced GC cells behaviour. Our findings demonstrated that high AKIP1 expression significantly correlated with clinical metastasis and unfavourable prognosis in patients with GC. Additionally, AKIP1 promoted GC cells proliferation, migration and invasion by activating Slug‐induced EMT.     

Alpha B‐crystallin promotes the invasion and metastasis of gastric cancer via NF‐κB‐induced epithelial‐mesenchymal transition

Alpha B‐crystallin (CRYAB) is overexpressed in a variety of cancers. However, little is known about its specific function and regulatory mechanism in gastric cancer. Here, we first explore the role of CRYAB in gastric cancer progression and metastasis. The expression of CRYAB was determined by western blot and immunohistochemistry in gastric cancer tissues. Besides, methods including stably transfected against CRYAB into gastric cancer cells, western blot, migration and invasion assays in vitro and metastasis assay in vivo were also conducted. The expression of CRYAB is up‐regulated in gastric cancer tissues compared with matched normal tissues. High expression level of CRYAB is closely correlated with cancer metastasis and shorter survival time in patients with gastric cancer. Additionally, CRYAB silencing significantly suppresses epithelial‐mesenchymal transition (EMT), migration and invasion of gastric cancer cells in vitro and in vivo, whereas CRYAB overexpression dramatically reverses these events. Mechanically, CRYAB facilitates gastric cancer cells invasion and metastasis via nuclear factor‐κ‐gene binding (NF‐κB)‐regulated EMT. These findings suggest that CRYAB expression predicts a poor prognosis in patients with gastric cancer. Besides, CRYAB contributes to gastric cancer cells migration and invasion via EMT, mediated by the NF‐κB signalling pathway, thus possibly providing a novel therapeutic target for gastric cancer.     

Low levels of AMPK promote epithelial‐mesenchymal transition in lung cancer primarily through HDAC4‐ and HDAC5‐mediated metabolic reprogramming

AMP‐activated protein kinase (AMPK) serves as a “supermetabolic regulator” that helps maintain cellular energy homeostasis. However, the role of AMPK in glucose metabolism reprogramming in lung cancer remains unclear. Here, our study shows that low AMPK expression correlates with metastasis and clinicopathologic parameters of non–small‐cell lung cancer. Low AMPK significantly enhances the Warburg effect in HBE and A549 cells, which in turn induces the expression of mesenchymal markers and enhances their invasion and migration. At the mechanistic level, low AMPK up‐regulates HK2 expression and glycolysis levels through HDAC4 and HDAC5. Collectively, our findings demonstrate that low AMPK‐induced metabolism can promote epithelial‐mesenchymal transition progression in normal bronchial epithelial cells and lung cancer cells, and increase the risk for tumour metastasis.