ADGRL4 Promotes Cell Growth, Aggressiveness, EMT, and Angiogenesis in Neuroblastoma via Activation of ERK/STAT3 Pathway.

BACKGROUND: Neuroblastoma (NB) is one of the most common pediatric solid tumors. Emerging evidence has indicated that ADGRL4 can act as a master regulator of tumor progression. In addition, it is well documented that the ERK/STAT3 signaling pathway can promote the proliferation, EMT, angiogenesis, and metastasis in tumors. The current study was formulated to elucidate the exact role of ADGRL4 in the malignant behaviors of NB cells and to investigate the intrinsic mechanism. METHODS: In this work, expression differences of ADGRL4 in human NB cell lines and HUVECs were assessed via RT-qPCR and western blot analysis. For functional experiments, sh-ADGRL4 was transfected into SK-N-SH cells to generate ADGRL4 knockdown stable cell line. Moreover, ADGRL4 knockdown stable SK-N-SH cells were treated with LM22B-10 (an ERK activator) for rescue experiments. CCK-8 colony formation determined NB cells' growth, migration, invasion, wound healing, and transwell assays. Meanwhile, proliferation-, metastasis- and EMT- associated proteins were also detected. Additionally, a tube formation assay was employed to evaluate in vitro angiogenesis. VM-cadherin, the marker of angiogenesis, was assessed using immunofluorescence staining. RESULTS: Data showed notably upregulated ADGRL4 in NB cells, especially in SK-NSH cells. ADGRL4 knockdown inhibited NB cell growth, migration, invasion, EMT, and in vitro angiogenesis. ADGRL4 knockdown inactivated ERK/STAT3 signaling pathway. Activation of the ERK/STAT3 signaling pathway partially rescued the tumor suppression effects of ADGRL4 knockdown on NB cells. CONCLUSION: To conclude, the downregulation of ADGRL4 may inhibit cell growth, aggressiveness, EMT, and angiogenesis in NB by inactivating the ERK/STAT3 signaling pathway.

Anisomycin inhibits the activity of human ovarian cancer stem cells via regulating antisense RNA NCBP2-AS2/MEK/ERK/STAT3 signaling.

BACKGROUND: Ovarian cancer stem cells (OCSCs) are the main cause of relapse and drug resistance in patients with ovarian cancer. Anisomycin has been shown to be an effective antitumor agent, but its mechanism of action in ovarian cancer remains elusive. METHODS: CD44+/CD133+ human OCSCs were isolated from human ovarian cancer tissues. OCSCs were interfered with using anisomycin and specific small-interfering RNA (siRNA). Microarray assay, MTT, in vivo tumorigenic experiments, transwell assay, cell cycle assay, colony formation assay, angiogenesis assay, and hematoxylin and eosin staining were used to detect the mechanism of anisomycin with respect to inhibiting the activity of OCSCs. Expression of the NCBP2-AS2/mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK)/signal transducer and activator of transcription 3 (STAT3) pathway was examined using western blotting, a quantitative real-time PCR (RT-qPCR) and immunofluorescence staining. Bioinformatics analysis was used for predictive analysis of NCBP2-AS2 expression in urogenital tumors. RESULTS: Microarray analysis showed that treatment with anisomycin significantly decreased the expression of antisense RNA NCBP2-AS2 in OCSCs. In vitro cellular experiments showed that interfering with endogenous antisense RNA NCBP2-AS2 using siRNA distinctly inhibited the proliferation, migration and angiogenesis of OCSCs, whereas in vivo animal experiments revealed decreased tumorigenesis in nude mice. Moreover, the results of RT-qPCR and western blotting demonstrated that both anisomycin treatment and NCBP2-AS2 silencing led to significant reductions in the mRNA and protein expression levels of NCBP2-AS2, MEK, ERK and STAT3. From a bioinformatic point of view, antisense RNA NCBP2-AS2 exhibited significantly differential expression between urogenital tumors and normal controls, and a similar expression pattern was found in the genes NCBP2, RPL35A, DNAJC19 and ECE2, which have similarity to NCBP2-AS2. CONCLUSIONS: Anisomycin suppresses the in vivo and in vitro activity of human OCSCs by downregulating the antisense RNA NCBP2-AS2/MEK/ERK/STAT3 signaling pathway, whereas the antisense RNA NCBP2-AS2 and genes with similarity have the potential to serve as markers for clinical diagnosis and prognosis of urogenital tumors.

Exosomal miR-21 determines lung-to-brain metastasis specificity through the DGKB/ERK axis within the tumor microenvironment.

BACKGROUND: Brain metastasis affects 20-40 % of lung cancer patients, severely diminishing their quality of life. This research focuses on miR-21, overexpressed in these patients and inversely associated with DGKB in the ERK/STAT3 pathway, suggesting a dysregulated pathway with therapeutic potential. AIMS: The objective was to investigate miR-21's role in lung cancer patients with brain metastases and whether targeting this pathway could improve treatment outcomes. We also examined the miR-21 content in tumor spheres-derived extracellular vesicles (EVs) and their influence on ERK/STAT3 signaling and metastasis. MATERIALS AND METHODS: Tumor spheres were created from metastatic lung cancer cells. We studied miR-21 levels in these spheres, their impact on macrophage polarization, and the transition of nonmetastatic lung cancer cells. Furthermore, we analyzed miR-21 content in EVs derived from these spheres and their effect on ERK/STAT3 signaling and metastasis potential. KEY FINDINGS: We found tumor spheres had high miR-21 levels, promoting macrophage polarization and, epithelial-mesenchymal transition. These spheres-derived EVs, enriched with miR-21, accelerated ERK/STAT3 signaling and metastasis. Silencing miR-21 and inhibiting ERK signaling with ulixertinib notably mitigated these effects. Moreover, ulixertinib reduced brain metastasis incidence and increased survival in a mouse model and led to reduced tumor sphere generation and miR-21 levels in EVs. SIGNIFICANCE: Our study highlights the exacerbation of lung-to-brain metastasis via miR-21-rich EV secretion. This underlines the therapeutic promise of targeting the miR-21/ERK/STAT3 pathway with ulixertinib for managing brain metastasis from lung cancer.

Icariside II potentiates the anti-PD-1 antitumor effect by reducing chemotactic infiltration of myeloid-derived suppressor cells into the tumor microenvironment via ROS-mediated inactivation of the SRC/ERK/STAT3 signaling pathways.

BACKGROUND: Immune checkpoint blockade agents, such as anti-PD-1 antibodies, show promising antitumor efficacy but only a limited response in patients with non-small cell lung cancer (NSCLC). Icariside II (IS), a metabolite of Herba Epimedii, is a COX-2 and EGFR inhibitor that can enhance the anti-PD-1 effect. This study aimed to evaluate the antitumor effect of IS in combination with anti-PD-1 and explore the underlying mechanism. METHODS: Tumor growth was assessed in Lewis Lung Cancer (LLC) tumor-bearing mice in seven groups (control, IS 20 mg/kg, IS 40 mg/kg, anti-PD-1, IS 20 mg/kg+anti-PD-1, IS 40 mg/kg+anti-PD-1, ERK inhibitor+anti-PD-1). Tumor-infiltrating immune cells were measured by flow cytometry. The mechanisms were explored by tumor RNA-seq and validated in LLC cells through molecular biological experiments using qRT‒PCR, ELISA, and western blotting. RESULTS: Animal experiments showed that IS in combination with anti-PD-1 further inhibited tumor growth and remarkably reduced the infiltration of myeloid-derived suppressor cells (MDSCs) into the tumor compared with anti-PD-1 monotherapy. RNA-seq and in vitro experiments showed that IS suppressed the chemotactic migration of MDSCs by downregulating the expression of CXC chemokine ligands 2 (CXCL2) and CXCL3. Moreover, IS promoted reactive oxygen species (ROS) generation and inhibited the activation of SRC/ERK/STAT3 in LLC cells, which are upstream signaling pathways of these chemokines. CONCLUSION: IS potentiates the anti-PD-1 anti-tumor effect by reducing chemotactic infiltration of the myeloid-derived suppressor cell into the tumor microenvironment, via ROS-mediated inactivation of SRC/ERK/STAT3 signaling pathways.

SIRT5 reduces the inflammatory response and barrier dysfunction in IL-17A-induced epidermal keratinocytes

Psoriasis is a chronic multisystemic inflammatory disease with inflammatory cell infiltration, hyperproliferation of keratinocytes in skin lesions, and epidermal barrier dysfunction. Normal human epidermal keratinocytes (NHEKs) were stimulated with interleukin 17A (IL-17A). The expression levels of sirtuin-5 (SIRT5) were analyzed by RT-qPCR and western blot assay. The proliferation levels of NHEKs were assessed by EdU staining. The expression of ELOVL1 and ELOVL4 was analyzed by RT-Qpcr, and the expression levels of filaggrin, loricrin, and aquaporin-3 were analyzed by RT-qPCR and western blot. Extracellular signal-regulated kinase 1/2 (ERK1/2) activator t-butylhydroquinone was used to activate ERK1/2. Here, we show that SIRT5 overexpression reduces cell viability and cell proliferation, and improves barrier dysfunction in IL-17A-treated human epidermal keratinocytes, this effect of which is significantly blunted by the ERK1/2 activator. In epidermal keratinocytes, SIRT5 decreases cell proliferation and inflammation and improves barrier dysfunction via ERK/STAT3. This study reveals the role of SIRT5 in the pathogenesis of psoriasis, epidermal hyperplasia, keratinocyte-mediated inflammatory responses, and barrier dysfunction, the role of which is mediated by ERK/STAT3 (AU)

SIRT5 reduces the inflammatory response and barrier dysfunction in IL-17A-induced epidermal keratinocytes.

Psoriasis is a chronic multisystemic inflammatory disease with inflammatory cell infiltration, hyperproliferation of keratinocytes in skin lesions, and epidermal barrier dysfunction. Normal human epidermal keratinocytes (NHEKs) were stimulated with interleukin 17A (IL-17A). The expression levels of sirtuin-5 (SIRT5) were analyzed by RT-qPCR and western blot assay. The proliferation levels of NHEKs were assessed by EdU staining. The expression of ELOVL1 and ELOVL4 was analyzed by RT-Qpcr, and the expression levels of filaggrin, loricrin, and aquaporin-3 were analyzed by RT-qPCR and western blot. Extracellular signal-regulated kinase 1/2 (ERK1/2) activator t-butylhydroquinone was used to activate ERK1/2. Here, we show that SIRT5 overexpression reduces cell viability and cell proliferation, and improves barrier dysfunction in IL-17A-treated human epidermal keratinocytes, this effect of which is significantly blunted by the ERK1/2 activator. In epidermal keratinocytes, SIRT5 decreases cell proliferation and inflammation and improves barrier dysfunction via ERK/STAT3. This study reveals the role of SIRT5 in the pathogenesis of psoriasis, epidermal hyperplasia, keratinocyte-mediated inflammatory responses, and barrier dysfunction, the role of which is mediated by ERK/STAT3.

Lysyl oxidase promotes renal fibrosis via accelerating collagen cross-link driving by ß-arrestin/ERK/STAT3 pathway.

Lysyl oxidase (LOX) is a copper-dependent monoamine oxidase whose primary function is the covalent cross-linking of collagen in the extracellular matrix (ECM). Evidence has shown that LOX is associated with cancer and some fibrotic conditions. We recently found that serum LOX is a potential diagnostic biomarker for renal fibrosis, but the mechanism by which LOX is regulated and contributes to renal fibrosis remains unknown. The current study demonstrates the following: (1) LOX expression was increased in fibrotic kidneys including ischemia-reperfusion injury-(IRI-), unilateral ureteral obstruction-(UUO-), and folic acid- (FA-) induced fibrotic kidneys as well as in the paraffin-embedded sections of human kidneys from the patients with renal fibrosis. (2) The increasing deposition and cross-linking of collagen induced by LOX was observed in IRI-, UUO- and FA-kidneys. (3) LOX was regulated by the ß-arrestin-ERK-STAT3 pathway in renal fibrosis. STAT3 was the downstream of AT1R-ß-arrestin-ERK, ERK entered the nucleus and activated STAT3-pY705 but not STAT3-pS727. (4) STAT3 nuclear subtranslocation and binding to the LOX promoter may be responsible for the upregulation of LOX expression. (5) Pharmacologic inhibition of LOX with BAPN in vivo inhibited the upregulation of LOX, decreased collagen over cross-linking and ameliorated renal fibrosis after ischemic injury. Collectively, these observations suggest that LOX plays an essential role in the development of renal fibrosis by catalyzing collagen over cross-linking. Thus, strategies targeting LOX could be a new avenue in developing therapeutics against renal fibrosis.

Preclinical Studies of Chiauranib Show It Inhibits Transformed Follicular Lymphoma through the VEGFR2/ERK/STAT3 Signaling Pathway.

Transformed follicular lymphoma (t-FL), for which there is no efficient treatment strategy, has a rapid progression, treatment resistance, and poor prognosis, which are the main reasons for FL treatment failure. In this study, we identified a promising therapeutic approach with chiauranib, a novel orally developed multitarget inhibitor targeting VEGFR/Aurora B/CSF-1R. We first determined the cytotoxicity of chiauranib in t-FL cell lines through CCK-8, EdU staining, flow cytometry, and transwell assays. We also determined the killing effect of chiauranib in a xenograft model. More importantly, we identified the underlying mechanism of chiauranib in t-FL tumorigenesis by immunofluorescence and Western blotting. Treatment with chiauranib significantly inhibited cell growth and migration, promoted apoptosis, induced cell cycle arrest in G2/M phase, and resulted in significant killing in vivo. Mechanistically, chiauranib suppresses the phosphorylation level of VEGFR2, which has an anti-t-FL effect by inhibiting the downstream MEK/ERK/STAT3 signaling cascade. In conclusion, chiauranib may be a potential therapy to treat t-FL, since it inhibits tumor growth and migration and induces apoptosis by altering the VEGFR2/ERK/STAT3 signaling pathway.

Effects of vinorelbine combined with adriamycin on breast cancer MCF-7 cells and related mechanisms / 中华内分泌外科杂志

Objective:To investigate the in vitro anti-cancer effect of Vinorelbine (NVB) combined with adriamycin (PLD) on human breast cancer MCF-7 cells and related mechanisms.Methods:The effects of NVB and PLD alone or in combination on the proliferation of breast cancer cells were detected by CCK-8 experiment. Flow cytometry was used to detect cell apoptosis and changes in reactive oxygen species (ROS) levels. Western blot experiment was carried out to detect protein expression.Results:The results of CCK-8 showed that compared with the blank control group, the inhibition rates of the vinorelbine treatment group, the adriamycin treatment group and the combined treatment group were 27.6%, 31.2% and 65.4%, compared with the NVB group and PLD group, the difference between the combined treatment group was statistically significant ( P=0.005 vs 0.001) . The results of flow cytometry showed that the proportion of apoptotic cells in each group was 3.54%, 16.95%, 15.01% and 32.24%, compared with the NVB group and PLD group, the difference between the combined treatment group was statistically significant ( P=0.006 vs 0.005) . The levels of reactive oxygen species in each group were 1, 1.03, 1.06 and 1.57, compared with the NVB group and PLD group, the difference between the combined treatment group was statistically significant ( P=0.008 vs 0.007) . Western blot results showed that the expression of p-ERK and p-STAT3 decreased after the combination of NVB and PLD, which inhibited the ERK/STAT3 signaling pathway. Conclusions:The combination of NVB and PLD can promote the apoptosis of breast cancer cells and inhibit the proliferation of breast cancer cells with high efficiency and low toxicity. Its mechanism of action may be related to the up-regulation of ROS levels in cells, thereby inhibiting the activation of the ERK/STAT3 pathway.

Gansui-Banxia Decoction extraction inhibits MDSCs accumulation via AKT /STAT3/ERK signaling pathways to regulate antitumor immunity in C57bl/6 mice.

BACKGROUND: Gansui-Banxia Decoction (GSBXD) is a classic formula of traditional Chinese medical (TCM) sage Zhang Zhongjing to treat stagnation of evil heat and obstruction of qi. At present GSBXD is wildly used to treat cancerous ascites, pleural effusion, peritoneal effusion, pericardial effusion, cranial cavity effusion and several types of cancers, such as hepatocellular carcinoma (HCC) and esophageal cancer. Myeloid-derived suppressor cells (MDSCs) are a kind of immature and heterogeneous cells which can suppress lymphocytes activation by forming a suppressive environment. MDSCs accumulation in peripheral blood and tumors are closely related to the cancer stage and low survival rate of clinical patients. The antitumor immune effect of GSBXD has not received widespread attention. PURPOSE: To investigate the effects of GSBXD on MDSCs accumulation and the mediators including AKT/STAT3/ERK signaling pathways. METHODS: The chemical components of GSBXD were analyzed by UHPLC-MS, and the putative pathways of GSBXD based on Network pharmacology were predicted. Mice were vaccinated with Hepatoma 22 (H22) to establish tumor growth model, which were then administrated with GSBXD ethanol extraction (0.49 mg/kg/day, 1.75 mg/kg/day), sorafenib (60 mg/kg) or saline for 14 days. The cell morphology was evaluated by hematoxylin and eosin (H&E) staining, and immunity cells were determined through flowcytometry analysis. The levels of cytokines production in blood were evaluated by using ELISA kits. STAT3, ERK and AKT/mTOR signaling transduction associated proteins were determined by Western blot. RESULTS: GSBXD could inhibit tumor growth and splenomegaly in H22 tumor model mice. Importantly, GSBXD reduced MDSCs accumulation and differentiation, and inhibited proliferation of F4/80+ CD11b+ macrophages and apoptosis of T cells and B cells, and increased the percentage of CD 3- NK1.1+ NK cells. To better understand the active component of GSBXD, the ethanol-extraction powdered GSBXD was prepared and analyzed by UHPLC-MS. Combined with these main chemical compounds, we predicted that the anti-tumor effect of GSBXD mainly mediated PI3K-AKT and RAS-MAPK signal pathways based on Network Pharmacology. Western blot analysis of tumor tissues and MDSCs cells demonstrated that phosphorylation of AKT, ERK and STAT3 were significantly reduced, specially the activation of ERK. The levels of IL-1ß and IFN-γ were significantly decreased by ELISA analysis. CONCLUSION: GSBXD exhibited antitumor immune activity by reducing the accumulation of MDSCs in vivo, which is possible via down-regulation of AKT/STAT3/ERK signaling pathway and suppression of IL-1ß and IFN-γ.

Hypoxia-Driven HIF-1α Activation Reprograms Pre-Activated NK Cells towards Highly Potent Effector Phenotypes via ERK/STAT3 Pathways.

NK cells are the predominant innate lymphocyte subsets specialized to kill malignant tumor cells. In patients with advanced cancer, hypoxic stress shapes NK cells toward tumor-resistant and immunosuppressive phenotypes, hence a strategy to restore NK function is critical for successful tumor immunotherapy. Here, we present evidence that pre-activation and subsequent HIF-1α-dependent metabolic shift of NK cells from oxidative phosphorylation into glycolysis are keys to overcome hypoxia-mediated impairment in NK cell survival, proliferation, and tumor cytotoxicity. Specifically, exposing NK cells to 7-9 days of normoxic culture followed by a pO2 of 1.5% hypoxia led to a highly potent effector phenotype via HIF-1α stabilization and upregulation of its target genes, BNIP3, PDK1, VEGF, PKM2, and LDHA. RNA sequencing and network analyses revealed that concomitant reduction of p21/p53 apoptotic pathways along with upregulation of cell cycle-promoting genes, CCNE1, CDC6, CDC20, and downregulation of cell cycle-arrest genes, CDKN1A, GADD45A, and MDM2 were accountable for superior expansion of NK cells via ERK/STAT3 activation. Furthermore, HIF-1α-dependent upregulation of the NKp44 receptor in hypoxia-exposed NK cells resulted in increased killing against K562, CEM, and A375 tumor targets both in-vitro and in-vivo tumor clearance assays. Therefore, hypoxic exposure on pre-activated proliferating NK cells triggered HIF-1α-dependent pathways to initiate coordinated regulation of cell cycle, apoptosis, and cytotoxicity at the global gene transcription level. Our results uncover a previously unidentified role of HIF-1α-mediated metabolic reprogramming that can reverse impaired NK effector phenotypes to generate requisite numbers of functionally robust NK cells for adoptive cellular therapy for clinical evaluation.

Overexpression of TEM8 promotes ovarian cancer progression via Rac1/Cdc42/JNK and MEK/ERK/STAT3 signaling pathways.

Tumor endothelial cell marker 8 (TEM8) is a type I transmembrane protein, that has been widely studied in the areas of anthrax toxin infection and tumor angiogenesis. However, the role of TEM8 in the progression of epithelial ovarian cancer (EOC) remains unclear. In this study, we determined that TEM8 was highly expressed in ovarian cancer and associated with poor prognosis in EOC patients. In vitro experiments showed that TEM8 overexpression significantly promoted ovarian cancer proliferation. TEM8 overexpression also promoted the G0/G1 phase transition, migration, and invasion of ovarian cancer cells but suppressed apoptosis. Moreover, experimental verification confirmed that TEM8 overexpression increased the expression of Ki-67, cyclin D1, Bcl2/Bax, MMP2, MMP9, and VEGFA and the phosphorylation of Rac1/Cdc42, JNK, MEK, ERK, and STAT3 (Ser727). Subsequently, the addition of RAC1 (EHop-016) and MEK (PD98059) pathway inhibitors suppressed malignant behaviors in the TEM8 overexpression group, which robustly indicated that TEM8 activated Rac1/Cdc42/JNK and MEK/ERK/STAT3 signaling pathways. In addition, we also revealed that the transcription factor GATA2 bound to the TATTAGTTATCTTT site of the TEM8 promoter region and regulated its expression. In conclusion, our study may provide a new theoretical basis for TEM8 application as a clinical biomarker and potential target in EOC patients.

Lymecycline reverses acquired EGFR-TKI resistance in non-small-cell lung cancer by targeting GRB2.

Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) were first-line treatments for NSCLC patients with EGFR-mutations. However, about 30 % of responders relapsed within six months because of acquired resistance. In this study, we used Connectivity Map (CMap) to discover a drug capable of reversing acquired EGFR-TKIs resistance. To investigate Lymecycline's ability to reverse acquired EGFR-TKIs resistance, two Icotinib resistant cell lines were constructed. Lymecycline's ability to suppress the proliferation of Icotinib resistant cells in vitro and in vivo was then evaluated. Molecular targets were predicted using network pharmacology and used to identify the molecular mechanism. Growth factor receptor-bound protein 2 (GRB2) is an EGFR-binding adaptor protein essential for EGFR phosphorylation and regulation of AKT/ERK/STAT3 signaling pathways. Lymecycline targeted GRB2 and inhibited the resistance of the cell cycle to EGFR-TKI, arresting disease progression and inducing apoptosis in cancer cells. Combined Lymecycline and Icotinib treatment produced a synergistic effect and induced apoptosis in HCC827R5 and PC9R10 cells. Cell proliferation in resistant cancer cells was significantly inhibited by the combined Lymecycline and Icotinib treatment in mouse models. Lymecycline inhibited the resistance of the cell cycle to EGFR-TKI and induced apoptosis in NSCLC by inhibiting EGFR phosphorylation and GRB2-mediated AKT/ERK/STAT3 signaling pathways. This provided strong support that Lymecycline when combined with EGFR targeting drugs, enhanced the efficacy of treatments for drug-resistant NSCLC.

Heme oxygenase-1 inhibition mediates Gas6 to enhance bortezomib-sensitivity in multiple myeloma via ERK/STAT3 axis.

Chemoresistance is still a critical challenge for efficient treatment of multiple myeloma (MM) during the bortezomib-based chemotherapy. Recent studies have suggested that heme oxygenase-1 (HO-1) is involved in apoptosis, proliferation and chemoresistance in cancer cells. Here we aim to investigate the role and mechanism of HO-1 in bortezomib-sensitivity to myeloma cells. In the study population, we found that HO-1 was highly expressed in CD138+ primary myeloma cells, which was positively associated with Gas6 expression and Gas6 plasma levels in MM patients. Downregulation of HO-1 using pharmacological inhibitor ZnPPIX or siRNA knockdown significantly enhanced myeloma cell sensitivity to bortezomib in human primary CD138+ cells, U266 and RPMI8226 cell lines. Mechanistically, HO-1 regulated Gas6 production via ERK/STAT3 axis. Combination with HO-1 inhibition increased bortezomib-induced apoptosis and antiproliferative effects via suppressing Gas6 production. These findings suggest that combination of bortezomib and HO-1 inhibitor may serve as a promising therapeutic target against bortezomib-resistant MM.

Influence of VEGFR single nucleotide polymorphisms on the efficacy of sunitinib therapy against renal cell carcinoma.

Single nucleotide polymorphisms (SNPs) of vascular endothelial growth factor receptor (VEGFR) may have effects on the MAPK/ERK/STAT3 signaling pathway, and the resulting phenotypes may influence the response to sunitinib-targeted therapy for renal cell carcinoma. In order to test this hypothesis patients with advanced renal cell carcinoma treated with sunitinib, were enrolled in our study. Peripheral blood samples were used to run a polymerase chain reaction-restriction fragment length polymorphism protocol to type candidate nucleotide polymorphism loci (VEGFR1, VEGFR2 and VEGFR3). The samples were also used in western blots to determine p-MAPK/ERK/STAT3 protein expression levels. The clinical responses to treatment were recorded and then a logistic regression method was applied to analyze the correlation between polymorphism of loci and effectiveness of sunitinib therapy. According to a follow-up visit (on average after 15 months of treatment) there were 16 complete responses (CR), 29 partial responses (PR) and 23 stable disease (SD) and progression of disease (PD) cases. Tests were carried out for 5 SNPs: VEGFR1 (rs664393), VEGFR2 (rsl870377 and rs7667298) and VEGFR3 (rs448012 and rs72816988). Mutation rates of rsl870377 and rs448012 loci in the CR+PR group were lower than those in the SD+PD group. No such differences were found for the other 3 loci. Relative expression levels of p-MAPk, p-ERK and p-STAT3 in the CR+PR group were significantly lower than those in the SD+PD group (P<0.05). The median progression-free survival and overall survival (OS) in the CR+PR group were higher than those in the SD+PD group (P<0.001). The median OS of the TT rsl870377 genotype was higher than that of the AA genotype, and the median OS of the GG rs448012 genotype was higher than that of the CC genotype (P<0.001). It was concluded through a logistic regression model that rsl870377 (AA) and rs448012 (GG) are independent risk factors closely associated with the effectiveness of sunitinib-targeted therapy on renal cell carcinoma. VEGFR SNPs are able to mediate the MAPK/ERK/STAT3 signaling pathway and therefore influence the effectiveness of sunitinib-targeted therapy, which makes them possible new therapeutic targets.