Targeting miR-31 represses tumourigenesis and dedifferentiation of BRAFV600E-associated thyroid carcinoma.

BACKGROUND: BRAFV600E is the most common genetic mutation in differentiated thyroid cancer (DTC) occurring in 60% of patients and drives malignant tumour cell phenotypes including proliferation, metastasis and immune-escape. BRAFV600E-mutated papillary thyroid cancer (PTC) also displays greatly reduced expression of thyroid differentiation markers, thus tendency to radioactive iodine (RAI) refractory and poor prognosis. Therefore, understanding the molecular mechanisms and main oncogenic events underlying BRAFV600E will guide future therapy development. METHODS: Bioinformatics and clinical specimen analyses, genetic manipulation of BRAFV600E-induced PTC model, functional and mechanism exploration guided with transcriptomic screening, as well as systematic rescue experiments were applied to investigate miR-31 function within BRAFV600E-induced thyroid cancer development. Besides, nanoparticles carrying miR-31 antagomirs were testified to alleviate 131I iodide therapy on PTC models. RESULTS: We identify miR-31 as a significantly increased onco-miR in BRAFV600E-associated PTC that promotes tumour progression, metastasis and RAI refractoriness via sustained Wnt/ß-catenin signalling. Mechanistically, highly activated BRAF/MAPK pathway induces miR-31 expression via c-Jun-mediated transcriptional regulation across in vitro and transgenic mouse models. MiR-31 in turn facilitates ß-catenin stabilisation via directly repressing tumour suppressors CEBPA and DACH1, which direct the expression of multiple essential Wnt/ß-catenin pathway inhibitors. Genetic functional assays showed that thyroid-specific knockout of miR-31 inhibited BRAFV600E-induced PTC progression, and strikingly, enhanced expression of sodium-iodide symporter and other thyroid differentiation markers, thus promoted 131I uptake. Nanoparticle-mediated application of anti-miR-31 antagomirs markedly elevated radio-sensitivity of BRAFV600E-induced PTC tumours to 131I therapy, and efficiently suppressed tumour progression in the pre-clinical mouse model. CONCLUSIONS: Our findings elucidate a novel BRAF/MAPK-miR-31-Wnt/ß-catenin regulatory mechanism underlying clinically BRAFV600E-associated DTC tumourigenesis and dedifferentiation, also highlight a potential adjuvant therapeutic strategy for advanced DTC.

Bortezomib Inhibits Lung Fibrosis and Fibroblast Activation without Proteasome Inhibition.

The U.S. Food and Drug Administration-approved proteasomal inhibitor bortezomib (BTZ) has attracted interest for its potential antifibrotic actions. However, neither its in vivo efficacy in lung fibrosis nor its dependence on proteasome inhibition has been conclusively defined. In this study, we assessed the therapeutic efficacy of BTZ in a mouse model of pulmonary fibrosis, developed an in vitro protocol to define its actions on diverse fibroblast activation parameters, determined its reliance on proteasome inhibition for these actions in vivo and in vitro, and explored alternative mechanisms of action. The therapeutic administration of BTZ diminished the severity of pulmonary fibrosis without reducing proteasome activity in the lung. In experiments designed to mimic this lack of proteasome inhibition in vitro, BTZ reduced fibroblast proliferation, differentiation into myofibroblasts, and collagen synthesis. It promoted dedifferentiation of myofibroblasts and overcame their characteristic resistance to apoptosis. Mechanistically, BTZ inhibited kinases important for fibroblast activation while inducing the expression of DUSP1 (dual-specificity protein phosphatase 1), and knockdown of DUSP1 abolished its antifibrotic actions in fibroblasts. Collectively, these findings suggest that BTZ exhibits a multidimensional profile of robust inhibitory actions on lung fibroblasts as well as antifibrotic actions in vivo. Unexpectedly, these actions appear to be independent of proteasome inhibition, instead attributable to the induction of DUSP1.

SIRT6 Negatively Regulates Schwann Cells Dedifferentiation via Targeting c-Jun During Wallerian Degeneration After Peripheral Nerve Injury.

Silent information regulator 6 (SIRT6) is a mammalian homolog of the nicotinamide adenine dinucleotide (NAD)-dependent deacetylase sirtuin family. Previous studies have been reported a pro-regenerative role of SIRT6 in central nervous system injury. However, the role of SIRT6 in peripheral nerve injury is still unknown. Given the importance and necessity of Schwann cell dedifferentiation response to peripheral nerve injury, we aim to investigate the molecular mechanism of SIRT6 steering Schwann cell dedifferentiation during Wallerian degeneration in injured peripheral nerve. Herein, we first examined the expression pattern of SIRT6 after peripheral nerve injury. Using the explants of sciatic nerve, an ex vivo model of nerve degeneration, we provided evidences indicating that SIRT6 inhibitor accelerates Schwann cell dedifferentiation as well as axonal and myelin degeneration, while SIRT6 activator attenuates this process. Moreover, in an in vitro Schwann cell dedifferentiation model, we found SIRT6 inhibitor promotes Schwann cell dedifferentiation through upregulating the expression of c-Jun. In addition, downregulation of c-Jun reverse the effects of SIRT6 inhibition on the Schwann cells dedifferentiation and axonal and myelin degeneration. In summary, we first described SIRT6 acts as a negative regulator for Schwann cells dedifferentiation during Wallerian degeneration and c-Jun worked as a direct downstream partner of SIRT6 in injured peripheral nerve.

Mangiferin Inhibits PDGF-BB-Induced Proliferation and Migration of Rat Vascular Smooth Muscle Cells and Alleviates Neointimal Formation in Mice through the AMPK/Drp1 Axis.

Mangiferin is a naturally occurring xanthone C-glycoside that is widely found in various plants. Previous studies have reported that mangiferin inhibits tumor cell proliferation and migration. Excessive proliferation and migration of vascular smooth muscle cells (SMCs) is associated with neointimal hyperplasia in coronary arteries. However, the role and mechanism of mangiferin action in neointimal hyperplasia is still unknown. In this study, a mouse carotid artery ligation model was established, and primary rat smooth muscle cells were isolated and used for mechanistic assays. We found that mangiferin alleviated neointimal hyperplasia, inhibited proliferation and migration of SMCs, and promoted platelets derive growth factors-BB- (PDGF-BB-) induced contractile phenotype in SMCs. Moreover, mangiferin attenuated neointimal formation by inhibiting mitochondrial fission through the AMPK/Drp1 signaling pathway. These findings suggest that mangiferin has the potential to maintain vascular homeostasis and inhibit neointimal hyperplasia.

TNF-α up-regulates Nanog by activating NF-κB pathway to induce primary rat spinal cord astrocytes dedifferentiation.

AIMS: Astrocytes re-acquire stem cell potential upon inflammation, thereby becoming a promising source of cells for regenerative medicine. Nanog is an essential transcription factor to maintain the characteristics of stem cells. We aimed to investigate the role of Nanog in astrocyte dedifferentiation. MAIN METHODS: TNF-α was used to induce the dedifferentiation of primary rat spinal cord astrocytes. The expression of immature markers CD44 and Musashi-1 was detected by qRT-PCR and immunofluorescence. The Nanog gene is knocked down by small interference RNA. Nanog expression was measured by qRT-PCR and western blotting. BAY 11-7082 was used to suppress NF-κB signals in astrocytes. NF-κB signaling was evaluated by Western blotting. KEY FINDINGS: Our results showed that TNF-α promoted the re-expression of CD44 and Musashi-1 in astrocytes. Dedifferentiated astrocytes could be induced to differentiate into oligodendrocyte lineage cells indicating that the astrocytes had pluripotency. In addition, TNF-α treatment activated NF-κB signaling pathway and up-regulated Nanog. Knockdown of Nanog reversed the increase of CD44 and Musashi-1 induced by TNF-α without affecting the activation of NF-κB signaling. Importantly, blocking NF-κB signaling by BAY 11-7082 inhibited the expression of immature markers suggesting that TNF-α induces dedifferentiation of astrocytes through the NF-κB signaling pathway. BAY 11-7082 could also inhibit the expression of Nanog, which indicated that Nanog was regulated by NF-κB signaling pathway. SIGNIFICANCE: These findings indicate that activation of the NF-κB signaling pathway through TNF-α leads to astrocytes dedifferentiation via Nanog. These results expand our understanding of the mechanism of astrocytes dedifferentiation.

Pro-tumoral behavior of omental adipocyte-derived fibroblasts in tumor microenvironment at the metastatic site of ovarian cancer.

Adipocyte-rich omentum offers "good soil" for disseminating ovarian cancer (OvCa), contributing to therapeutic difficulty. However, little is understood about the association between adipocytes and tumor growth at peritoneal dissemination site. Herein, we report the induction of adipocyte dedifferentiation by OvCa cells and pro-tumorigenic effects of resulted adipocyte-derived fibroblasts. We confirmed that malignant ascites promoted the dedifferentiation of the primary human adipocytes obtained from surgical omental specimen into omental adipocyte-derived fibroblast (O-ADF) that possess both mesenchymal stem cell and myofibroblast-like features. This promotion of dedifferentiation by malignant ascites was blocked by addition of Wnt signaling inhibitor. The effects of dedifferentiated adipocytes in proliferation and migration of OvCa cells were analyzed with in vitro coculturing experimental models and in vivo mice model, and we demonstrated that OvCa cell lines showed enhanced proliferative characteristics, as well as increased migratory abilities upon coculturing with O-ADF. Additionally, exogenous transforming growth factor-ß1 augmented desmoplastic morphological change of O-ADF, leading to higher proliferative ability. Our results suggest that OvCa cells promote dedifferentiation of peritoneal adipocytes by activating Wnt/ß-catenin signaling, and generated O-ADFs exhibit pro-tumoral hallmarks.

Targeting cancer cell plasticity by HDAC inhibition to reverse EBV-induced dedifferentiation in nasopharyngeal carcinoma.

Application of differentiation therapy targeting cellular plasticity for the treatment of solid malignancies has been lagging. Nasopharyngeal carcinoma (NPC) is a distinctive cancer with poor differentiation and high prevalence of Epstein-Barr virus (EBV) infection. Here, we show that the expression of EBV latent protein LMP1 induces dedifferentiated and stem-like status with high plasticity through the transcriptional inhibition of CEBPA. Mechanistically, LMP1 upregulates STAT5A and recruits HDAC1/2 to the CEBPA locus to reduce its histone acetylation. HDAC inhibition restored CEBPA expression, reversing cellular dedifferentiation and stem-like status in mouse xenograft models. These findings provide a novel mechanistic epigenetic-based insight into virus-induced cellular plasticity and propose a promising concept of differentiation therapy in solid tumor by using HDAC inhibitors to target cellular plasticity.

Melanoma dedifferentiation induced by IFN-γ epigenetic remodeling in response to anti-PD-1 therapy.

Melanoma dedifferentiation has been reported to be a state of cellular resistance to targeted therapies and immunotherapies as cancer cells revert to a more primitive cellular phenotype. Here, we show that, counterintuitively, the biopsies of patient tumors that responded to anti-programmed cell death 1 (anti-PD-1) therapy had decreased expression of melanocytic markers and increased neural crest markers, suggesting treatment-induced dedifferentiation. When modeling the effects in vitro, we documented that melanoma cell lines that were originally differentiated underwent a process of neural crest dedifferentiation when continuously exposed to IFN-γ, through global chromatin landscape changes that led to enrichment in specific hyperaccessible chromatin regions. The IFN-γ-induced dedifferentiation signature corresponded with improved outcomes in patients with melanoma, challenging the notion that neural crest dedifferentiation is entirely an adverse phenotype.

Cilostazol is an effective causal therapy for preventing paclitaxel-induced peripheral neuropathy by suppression of Schwann cell dedifferentiation.

Chemotherapy-induced peripheral neuropathy (CIPN) can lead to discontinuation of chemotherapy and is consequently a serious impediment to effective cancer treatment. Due to our limited understanding of mechanisms underlying the pathogenesis of CIPN, no causal therapy has been approved for relief of this condition. We previously demonstrated that taxanes (paclitaxel and docetaxel) induce Schwann cell dedifferentiation, characterized by increased expression of p75 and galectin-3, ultimately leading to demyelination. These changes appear to be responsible for CIPN pathogenesis. This study was designed to identify a novel candidate therapeutic for CIPN with the ability to suppress paclitaxel-induced Schwann cell dedifferentiation. Given that elevation of cyclic adenosine monophosphate (cAMP) signaling participates in Schwann cell differentiation, we performed immunocytochemical screening of phosphodiesterase (PDE) inhibitors. We found that the PDE3 inhibitor cilostazol strongly promoted differentiation of primary cultures of rat Schwann cells via a mechanism involving cAMP/exchange protein directly activated by cAMP (Epac) signaling. Co-treatment with cilostazol prevented paclitaxel-induced dedifferentiation of Schwann cell cultures and demyelination in a mixed culture of Schwann cells and dorsal root ganglia neurons. Notably, continuous oral administration of cilostazol suppressed Schwann cell dedifferentiation within the sciatic nerve and the development of mechanical hypersensitivity in a mouse model of paclitaxel-related CIPN. Importantly, cilostazol potentiated, rather than inhibited, the anti-cancer effect of paclitaxel on the human breast cancer cell line MDA-MB-231. These findings highlight the potential utility of cilostazol as a causal therapeutic that avoids the development of paclitaxel-related CIPN without compromising anti-cancer properties.

Direct reprogramming of epithelial cell rests of malassez into mesenchymal-like cells by epigenetic agents.

The DNA demethylating agent, 5-Azacytidine (5Aza), and histone deacetylase inhibitor, valproic acid (Vpa), can improve the reprogramming efficiencies of pluripotent cells. This study aimed to examine the roles of 5Aza and Vpa in the dedifferentiation of epithelial cell rests of Malassez (ERM) into stem-like cells. Additionally, the ability of stem-like cells to differentiate into mesenchymal cells was evaluated. ERM was cultured in embryonic stem cell medium (ESCM) with 1 µM of 5Aza, or 2 mM of Vpa, or a combination of 5Aza and Vpa. The cells stimulated with both 5Aza and Vpa were named as progenitor-dedifferentiated into stem-like cells (Pro-DSLCs). The Pro-DSLCs cultured in ESCM alone for another week were named as DSLCs. The stem cell markers were significantly higher in the DSLCs than the controls (no additions). The mRNA and protein levels of the endothelial, mesenchymal stem, and osteogenic cell markers were significantly higher in the Pro-DSLCs and DSLCs than the controls. The combination of a demethylating agent and a deacetylated inhibitor induced the dedifferentiation of ERM into DSLCs. The Pro-DSLCs derived from ERM can be directly reprogrammed into mesenchymal-like cells without dedifferentiation into stem-like cells. Isolated ERM treated with epigenetic agents may be used for periodontal regeneration.

Autophagy participants in the dedifferentiation of mouse 3T3-L1 adipocytes triggered by hypofunction of insulin signaling.

Our previous data indicate that both insulin and IGF-1 signallings dysfunction promotes the dedifferentiation of primary human and mouse white adipocytes. Based on the fact that insulin activates mTOR and inhibits autophagy, and autophagy deficiency can inhibit the differentiation of white adipocytes, we speculate that autophagy may be related to the dedifferentiation of white adipocytes. We investigated the underlying mechanism of autophagy during dedifferentiation of mouse 3T3-L1 adipocytes. After incomplete inhibition of insulin and IGF-1 signallings, 3T3-L1 adipocytes manifest dedifferentiation accompanied with an increase of autophagy level. If induction only of autophagy in the adipocytes, then the cells also occur somewhat dedifferentiation, and with a slight decrease of insulin signal, while its degree was weaker than insulin signal inhibited cells. Notably, after inhibition of the insulin and IGF-1 signallings and simultaneously inducing autophagy, the dedifferentiation of 3T3-L1 adipocytes was the most obvious compared with other groups, and the insulin and IGF-1 signallings decreases was greater than the cells with inhibition only of insulin signalling. If inhibition of both insulin signal and autophagy simultaneously, the dedifferentiation of the adipocytes reveals similar tendencies to the cells that insulin signal was inhibited. No significant dedifferentiation occurs of 3T3-L1 cells if only inhibition of autophagy. Taken all together, in this study, we proved that autophagy is positively related to the dedifferentiation of 3T3-L1 adipocytes and is regulated through the insulin-PI3K-AKT-mTOCR1-autophagy pathway. Autophagy may also has a certain degree of negative feedback affect on the insulin signalling of 3T3-L1 cells. Our work may help to better understand the biological properties of mature adipocytes and may help formulate anti-obesity strategies by regulating insulin and insulin signaling level.

Detrimental activation of AhR pathway in cancer: an overview of therapeutic strategies.

Sustained transcriptional activation of the aryl hydrocarbon receptor (AhR) promotes tumour growth and impairs the immune defence, at least for cutaneous melanoma and glioma. AhR ligands are produced by the tumour microenvironment (TME) and by the tumour itself (intracrine). The recent identification of interleukin-4-induced-1 (IL4I1), a parallel pathway to indoleamine 2 3-dioxygenase 1 (IDO1)/ tryptophan 2,3-dioxygenase (TDO), and its ability to generate AhR ligands, confirms that a complete inhibition of AhR ligand production might be difficult to reach. Here, we have focused on recent discoveries explaining the large varieties of AhR ligands and the functional consequences in terms of cancer cell plasticity and consecutive therapy resistance. We also examined therapeutic strategies targeting the AhR signalling pathway and their possible adverse effects. Since the end of 2019, two phase I clinical trials have investigated the ability of the AhR antagonist to 'reset' the immune system and re-sensitize the cancer cells to therapies by preventing their dedifferentiation.

The differentiation effect of bone morphogenetic protein (BMP) on human amniotic epithelial stem cells to express ectodermal lineage markers.

Stem cells are a promising tool for treatment of a variety of degenerative diseases. Human amniotic epithelial stem cells (hAECs) have desirable and unique characteristics that make them a proper candidate for cell therapy. In this study, we have investigated the effects of BMP-4 (bone morphogenetic protein-4) and its inhibition on differentiation of AECs into ectodermal lineages. Analysis of AEC-derived ectodermal lineages (neurons and keratinocytes) was performed by using flow cytometry technique for Map2 and ß-tubulin (as neuron markers), Olig2 and MBP (as oligodendrocyte markers), and K14 and K10 (as keratinocyte markers). The results of this study illustrated that noggin (as BMP antagonist), BMP4, and both BMP4 and heparin (together or separately) increased neural and keratinocyte marker expression, respectively. The expression of markers MAP2, olig2, and K14 in hAECs has been significantly decreased 21 days after exposure to differentiation medium (without growth factors) compared with isolation day, which supports the hypothesis that AECs can be dedifferentiated into pluripotent cells. Moreover, activation and inhibition of BMP signaling have no effects on viability of hAECs. The results of this study showed that BMP signaling and its inhibition are the key factors for ectodermal lineage differentiation of amnion-derived stem cells.

m6A RNA methylation-mediated HNF3γ reduction renders hepatocellular carcinoma dedifferentiation and sorafenib resistance.

Hepatocyte nuclear factor 3γ (HNF3γ) is a hepatocyte nuclear factor, but its role and clinical significance in hepatocellular carcinoma (HCC) remain unclear. Herein, we report that HNF3γ expression is downregulated in patient HCC and inversely correlated with HCC malignancy and patient survival. Moreover, our data suggested that the HNF3γ reduction in HCC could be mediated by METTL14-dependent m6A methylation of HNF3γ mRNA. HNF3γ expression was increased during hepatic differentiation and decreased in dedifferentiated HCC cells. Interestingly, HNF3γ delivery promoted differentiation of not only HCC cells but also liver CSCs, which led to suppression of HCC growth. Mechanistic analysis suggested an HNF3γ-centered regulatory network that includes essential liver differentiation-associated transcription factors and functional molecules, which could synergistically facilitate HCC cell differentiation. More importantly, enforced HNF3γ expression sensitized HCC cells to sorafenib-induced growth inhibition and cell apoptosis through transactivation of OATP1B1 and OATP1B3 expression, which are major membrane transporters for sorafenib uptake. Clinical investigation showed that patient-derived HCC xenografts with high HNF3γ expression exhibited a sorafenib response and patients with high HCC HNF3γ levels benefited from sorafenib therapy. Together, these results suggest that HNF3γ plays an essential role in HCC differentiation and may serve as a therapeutic target and predictor of sorafenib benefit in patients.

Concerted cell and in vivo screen for pancreatic ductal adenocarcinoma (PDA) chemotherapeutics.

PDA is a major cause of US cancer-related deaths. Oncogenic Kras presents in 90% of human PDAs. Kras mutations occur early in pre-neoplastic lesions but are insufficient to cause PDA. Other contributing factors early in disease progression include chronic pancreatitis, alterations in epigenetic regulators, and tumor suppressor gene mutation. GPCRs activate heterotrimeric G-proteins that stimulate intracellular calcium and oncogenic Kras signaling, thereby promoting pancreatitis and progression to PDA. By contrast, Rgs proteins inhibit Gi/q-coupled GPCRs to negatively regulate PDA progression. Rgs16::GFP is expressed in response to caerulein-induced acinar cell dedifferentiation, early neoplasia, and throughout PDA progression. In genetically engineered mouse models of PDA, Rgs16::GFP is useful for pre-clinical rapid in vivo validation of novel chemotherapeutics targeting early lesions in patients following successful resection or at high risk for progressing to PDA. Cultured primary PDA cells express Rgs16::GFP in response to cytotoxic drugs. A histone deacetylase inhibitor, TSA, stimulated Rgs16::GFP expression in PDA primary cells, potentiated gemcitabine and JQ1 cytotoxicity in cell culture, and Gem + TSA + JQ1 inhibited tumor initiation and progression in vivo. Here we establish the use of Rgs16::GFP expression for testing drug combinations in cell culture and validation of best candidates in our rapid in vivo screen.

Adenylate Cyclase Toxin Tinkering With Monocyte-Macrophage Differentiation.

Circulating inflammatory monocytes are attracted to infected mucosa and differentiate into macrophage or dendritic cells endowed with enhanced bactericidal and antigen presenting capacities. In this brief Perspective we discuss the newly emerging insight into how the cAMP signaling capacity of Bordetella pertussis adenylate cyclase toxin manipulates the differentiation of monocytes and trigger dedifferentiation of the alveolar macrophages to facilitate bacterial colonization of human airways.

The aryl hydrocarbon receptor promotes inflammation-induced dedifferentiation and systemic metastatic spread of melanoma cells.

The aryl hydrocarbon receptor (AHR) is a ligand binding-transcription factor of the basic helix-loop-helix family regulating multiple cellular functions such as differentiation, cell cycle, apoptosis, and inflammatory reactions. In neoplastic diseases, the AHR has been described to modulate proliferation and differentiation in dichotomous ways, either inhibiting or augmenting the growth of tumors. The precise role of AHR in melanoma is mostly unknown. Here, we report a functional effect of AHR activation on inflammation-induced melanoma cell dedifferentiation and the development of lung metastases in a mouse model. Via in silico analyses of "The Cancer Genome Atlas" human melanoma cohort, we detected a correlation between AHR expression levels and a dedifferentiated melanoma cell phenotype with an invasive gene signature, which we were able to functionally recapitulate in a panel of human melanoma cell lines. Both human and mouse melanoma cell lines upregulated AHR expression after inflammatory stimulation with tumor necrosis factor-α (TNF-α). Activation of AHR in human and mouse melanoma cell lines with the endogenous ligand formylindolo(3,2-b)carbazole (FICZ) promoted inflammation-induced dedifferentiation in vitro. Importantly, mouse melanoma cells with CRISPR/Cas9-mediated disruption of the AHR gene showed impaired in vivo tumor growth after transplantation in the skin as well as decreased numbers of spontaneous lung metastases. Taken together, our results demonstrate a functional role for AHR expression in melanoma development and metastatic progression. This provides a scientific basis for future experiments that further dissect the underlying molecular mechanisms and assess the potential for AHR inhibition as part of multimodal melanoma treatment strategies.

Apatinib attenuates phenotypic switching of arterial smooth muscle cells in vascular remodelling by targeting the PDGF Receptor-ß.

Apatinib (YN968D1) is a small-molecule tyrosine kinase inhibitor（TKI）which can inhibit the activity of vascular endothelial growth factor receptor-2 (VEGFR-2). It has been reported that apatinib has anti-tumour effect of inhibiting proliferation and inducing apoptosis of a variety of solid tumour cells, whereas its effect on vascular smooth muscle cells (VSMC) remains unclear. This study investigated the effect of apatinib on phenotypic switching of arterial smooth muscle cells in vascular remodelling. Compared to the vehicle groups, mice that were performed carotid artery ligation injury and treated with apatinib produced a reduction in abnormal neointimal area. For in vitro experiment, apatinib administration inhibited VSMC proliferation, migration and reversed VSMC dedifferentiation with the stimulation of platelet-derived growth factor type BB (PDGF-BB).In terms of mechanism, with the preincubation of apatinib, the activations of PDGF receptor-ß (PDGFR-ß) and phosphoinositide-specific phospholipase C-γ1 (PLC-γ1) induced by PDGF-BB were inhibited in VSMCs. With the preincubation of apatinib, the phosphorylation of PDGFR-ß, extracellular signal-related kinases (ERK1/2) and Jun amino-terminal kinases (JNK) induced by PDGF-BB were also inhibited in rat vascular smooth muscle cell line A7r5. Herein, we found that apatinib attenuates phenotypic switching of arterial smooth muscle cells induced by PDGF-BB in vitro and vascular remodelling in vivo. Therefore, apatinib is a potential candidate to treat vascular proliferative diseases.

How Tumor Cell Dedifferentiation Drives Immune Evasion and Resistance to Immunotherapy.

Immunotherapy has revolutionized cancer treatment, yet most patients do not respond. While tumor antigens are needed for effective immunotherapy, a favorable tumor immune microenvironment is also critical. In this review, we discuss emerging evidence that tumor cells exploit cellular plasticity and dedifferentiation programs to avoid immune surveillance, which in turn drives metastatic dissemination and resistance to immunotherapy. A deeper understanding of these programs may provide novel opportunities to enhance the efficacy of existing immunotherapies.