Mingxiang Ye

Curcumin promotes apoptosis by activating the p53-miR-192-5p/215-XIAP pathway in non-small cell lung cancer

Curcumin has attracted increasing interest as an anti-cancer drug for decades. The mechanisms of action involve multiple cancer-related signaling pathways. Recent studies highlighted curcumin has epigenetic regulatory effects on miRNA in cancers. In the present study, we demonstrated the proapoptotic effects of curcumin in vitro and in vivo. miRNA microarray and qPCR indicated that miR-192-5p and miR-215 were the most responsive miRNAs upon curcumin treatment in H460 and A427 cells. Functional studies showed miR-192-5p/215 were putative tumor suppressors in non-small cell lung cancer. Curcumin also promoted miR-192-5p/215 expressions in A549 cells (p53 wild type) but not in H1299 cells (p53-null). Conditional knockdown of p53 by tetracycline inducible expression system significantly abrogated curcumin-induced miR-192-5p/215 upregulation in the p53 wild-type H460, A427 and A549 cells. Conversely, ectopic expression of exogenous wild-type but not R273H mutant p53 in the p53-null H1299 cells enabled miR-192-5p/215 response to curcumin treatment. The proapoptotic effects of curcumin also depended on miR-192-5p/215 induction, and antagonizing miR-192-5p/215 expression attenuated curcumin-induced apoptosis in H460, A427 and A549 cells, but not in H1299 cells. Finally, X-linked inhibitor of apoptosis (XIAP) is proved to be a novel transcriptional target of miR-192-5p/215. Taken together, this study highlights that the proapoptotic effects of curcumin depend on miR-192-5p/215 induction and the p53-miR-192-5p/215-XIAP pathway is an important therapeutic target for non-small cell lung cancer.

Curcumin reverses cis-platin resistance and promotes human lung adenocarcinoma A549/DDP cell apoptosis through HIF-1α and caspase-3 mechanisms.

Curcumin, a yellow pigment derived from Curcuma longa Linn, has been favored by the Eastern as dietary ingredients for centuries. During the past decade, extensive investigations have revealed curcumin sensitized various chemotherapeutic agents in human breast, colon, pancreas, gastric, liver, brain and hematological malignant disorders in vivo and in vitro. Several pathways and specific targets including NF-κB, STAT3, COX-2, Akt and multidrug resistant protein have been identified to facilitate curcumin as a chemosensitizer. Recent studies suggest HIF-1α participated in the development of drug resistance in cancer cells and targeting HIF-1α either by RNAi or siRNA successfully overcame chemotherapeutic resistance. To investigate the mechanism basis of curcumin as a chemosensitizer in lung cancer, we examined curcumins effects on HIF-1α in cis-platin (DDP) sensitive A549 and resistant A549/DDP cell lines by RT-PCR and Western blot. HIF-1α in A549/DDP cells was found to be overexpressed at both mRNA and protein levels together with a poor response to DDP. Results from transient transfection and flow cytometry showed the HIF-1α abnormality contributed to DDP resistance in A549/DDP lung cancer cells. Combined curcumin and DDP treatment markedly inhibited A549/DDP cells proliferation, reversed DDP resistance and triggered apoptotic death by promoting HIF-1α degradation and activating caspase-3, respectively. Expression of HIF-1α-dependent P-gp also seemed to decrease as response to curcumin in a dose-dependent manner. Our findings shed light on drug resistant reversing effect of curcumin in lung cancer cells by inhibiting HIF-1α expression and activating caspase-3.

Curcumin: Updated Molecular Mechanisms and Intervention Targets in Human Lung Cancer

Curcumin, a yellow pigment derived from Curcuma longa Linn, has attracted great interest in the research of cancer during the past decades. Extensive studies documented that curcumin attenuates cancer cell proliferation and promotes apoptosis in vivo and in vitro. Curcumin has been demonstrated to interact with multiple molecules and signal pathways, which makes it a potential adjuvant anti-cancer agent to chemotherapy. Previous investigations focus on the mechanisms of action for curcumin, which is shown to manipulate transcription factors and induce apoptosis in various kinds of human cancer. Apart from transcription factors and apoptosis, emerging studies shed light on latent targets of curcumin against epidermal growth factor receptor (EGFR), microRNAs (miRNA), autophagy and cancer stem cell. The present review predominantly discusses significance of EGFR, miRNA, autophagy and cancer stem cell in lung cancer therapy. Curcumin as a natural phytochemicals could communicate with these novel targets and show synergism to chemotherapy. Additionally, curcumin is well tolerated in humans. Therefore, EGFR-, miRNA-, autophagy- and cancer stem cell-based therapy in the presence of curcumin might be promising mechanisms and targets in the therapeutic strategy of lung cancer.

ALK and ROS1 as targeted therapy paradigms and clinical implications to overcome crizotinib resistance.

During the past decade, more than 10 targetable oncogenic driver genes have been validated in non-small cell lung cancer (NSCLC). Anaplastic lymphoma kinase (ALK) and ROS1 kinase are two new driver genes implicated in ALK- and ROS1-rearranged NSCLC. Inhibition of ALK and ROS1 by crizotinib has been reported to be highly effective and well tolerated in these patients. However, resistance to crizotinib emerges years after treatment, and increasing efforts have been made to overcome this issue. Here, we review the biology of ALK and ROS1 and their roles in cancer progression. We also summarize the ongoing and completed clinical trials validating ALK and ROS1 as targets for cancer treatment. In the last section of the review, we will discuss the molecular mechanisms of crizotinib resistance and focus approaches to overcome it. This review describes an exciting new area of research and may provide new insights for targeted cancer therapies.

Targeting FBW7 as a Strategy to Overcome Resistance to Targeted Therapy in Non–Small Cell Lung Cancer

Inhibition of EGFR and anaplastic lymphoma kinase (ALK) signaling is highly effective in a subgroup of non-small cell lung cancer (NSCLC) patients with distinct clinicopathologic features. However, resistance to EGFR and ALK inhibitors inevitably occurs, and the molecular mechanism underlying resistance is not fully understood. In this study, we report a PI3K/Akt- and MEK/ERK-independent resistance mechanism by which loss of the E3 ubiquitin ligase F-box and WD repeat domain containing 7 (FBW7α) leads to targeted therapy resistance via stabilization of antiapoptotic protein MCL-1. Using a panel of in vitro and in vivo studies, we showed that the regulatory machinery responsible for MCL-1 protein degradation was a step-wise event involving phosphorylation and nucleus translocation. ERK cooperated with GSKβ to phosphorylate MCL-1 Ser159 residue, which enabled MCL-1 to translocate into the nucleus and bind FBW7. Defects in this sequence impaired MCL-1 degradation and cell apoptosis, recapitulating phenotypes observed in FBW7 deficiency. Downregulation of FBW7 was found in EGFR inhibitor-resistant human NSCLC specimens and correlated with increased MCL-1 protein expression. Reactivation of FBW7 sensitized resistant cells to targeted therapy and facilitated MCL-1 degradation. Overall, our study provides proof-of-principle insight into a PI3K/Akt- and MEK/ERK-independent resistant model and suggests that targeting FBW7 can overcome resistance to targeted therapy. Cancer Res; 77(13); 3527-39. ©2017 AACR.

Rapidly Progressive Diffuse Cystic Lesions as a Radiological Hallmark of Lung Adenocarcinoma

CASE PRESENTATION A 39-year-old nonsmoking man presented to us with complaints of progressive hoarseness and nonproductive cough. Laboratory examinations revealed elevated serum carcino-embryonic antigen (15.49 ng/ml) and cancer antigen125 (40.01 U/ml). Chest computed tomography (CT) 1 month earlier showed a 25 20 mm central located mass in the left upper lobe and diffused cystic lesions in bilateral lungs (Figure 1). Repeated chest CT scan in our institution showed increased size of the mass at 35 30 mm and rapidly enlarged, widespread, disseminated thin-walled cystic lesions in bilateral lungs (Figure 2). Bronchoscopy revealed an endobronchial whitish lesion in the left apicoposterior segment bronchus but was otherwise normal. Histologic and immunohistochemical examination of the mass and blind-aspirated lung specimen established the diagnosis of adenocarcinoma. The cancer cells were poorly differentiated with a positive reaction to carcino-embryonic antigen, thyroid transcription factor 1, and cytokeratin 7 staining. Positron emission tomography revealed heterogeneous uptake of the mass, cystic lesion, and mediastinal lymph nodes, suggesting intrapulmonary metastasis. His clinical stage was T1N2M1 stage IV and epidermal growth factor receptor mutation test was negative. He underwent cisplatin/gemcitabine chemotherapy for four cycles. The next 3 months follow-up documented significant improvement and the patient was alive and stable. This report highlights that lung adenocarcinoma might present as multiple cystic lesions on rare occasions.1 It is essential to maintain a high index of suspicion for adenocarcinoma in patients with mediastinal mass and diffused thinwalled cystic lesions as observed in our case.

Polydatin Attenuates Hypoxic Pulmonary Hypertension and Reverses Remodeling through Protein Kinase C Mechanisms

Hypoxic pulmonary hypertension is a life-threatening emergency if untreated. Consistent pulmonary hypertension also leads to arteries and ventricular remodeling. The clinical therapeutic strategy for pulmonary hypertension and the corresponding remodeling mainly interacts with NO, angiotensin II (Ang II) and elevated endothelin (ET) targets. In the present study, we evaluated the effects of polydatin on hypoxia-induced pulmonary hypertension. It was observed that polydatin attenuated hypoxic pulmonary hypertension, reversed remodeling, and regulated NO, Ang II, ET contents in the serum and lung samples. However, forced activation of PKC signaling by its selective activator thymeleatoxin (THX) could abate the effects of polydatain. These results suggest that polydatin might be a promising candidate for hypoxic pulmonary treatment through interaction with PKC mechanisms.

siRNA delivered by EGFR-specific scFv sensitizes EGFR-TKI-resistant human lung cancer cells.

The overexpression of epidermal growth factor receptor (EGFR) is closely associated with a poor outcome in non-small cell lung cancer (NSCLC), and EGFR is an ideal biomarker for the targeted therapy of NSCLC. Although patients with EGFR-activating mutations respond to EGFR tyrosine kinase inhibitors (EGFR-TKIs), they eventually acquire resistance, which typically results from a secondary EGFR mutation or the activation of other signaling pathways. Novel approaches to overcome or prevent EGFR-TKI resistance are clinically important. In this study, we developed an EGFR-scFv-arginine nonamer peptide fusion protein, s-9R, as an siRNA carrier. Here, we show that s-9R effectively and specifically delivers EGFR-siRNAs, KRAS-siRNA and MET-siRNA into NSCLC cells and silences the expression of target genes. The sensitivity of NSCLC cells to gefitinib was restored after treatment with the s-9R/siRNA complex, and the apoptosis rates of the treated cells were significantly higher than those of the control groups. Furthermore, the co-administration of s-9R/siRNA and gefitinib successfully suppressed the progression of H1975 xenograft tumors and extended the life span of tumor-bearing nude mice. Collectively, the results of this study provide not only a new scFv derivative for delivering siRNA into EGFR-overexpressing, TKI-resistant NSCLC cells but also a novel method for overcoming TKI resistance.

Activation of the Aryl Hydrocarbon Receptor Leads to Resistance to EGFR TKIs in Non–Small Cell Lung Cancer by Activating Src-mediated Bypass Signaling

Purpose: The aryl hydrocarbon receptor (AhR) has been generally recognized as a ligand-activated transcriptional factor that responds to xenobiotic chemicals. Recent studies have suggested that the expression of AhR varies widely across different cancer types and cancer cell lines, but its significance in cancer treatment has yet to be clarified. Experimental Design: AhR expression in non–small cell lung cancer (NSCLC) was determined by Western blotting and IHC staining. In vitro and in vivo functional experiments were performed to determine the effect of AhR on sensitivity to targeted therapeutics. A panel of biochemical assays was used to elucidate the underlying mechanisms. Results: A high AhR protein level indicated an unfavorable prognosis for lung adenocarcinoma. Inhibition of AhR signaling sensitized EGFR tyrosine kinase inhibitors (TKIs) in NSCLC cells that express high level of endogenous AhR protein. Notably, activation of AhR by pharmacologic and molecular approaches rendered EGFR-mutant cells resistant to TKIs by restoring PI3K/Akt and MEK/Erk signaling through activation of Src. In addition, we found that AhR acts as a protein adaptor to mediate Jak2–Src interaction, which does not require the canonical transcriptional activity of AhR. Conclusions: Our results reveal a transcription-independent function of AhR and indicate that AhR may act as a protein adaptor that recruits kinases bypassing EGFR and drives resistance to TKIs. Accordingly, targeting Src would be a strategy to overcome resistance to EGFR TKIs in AhR-activated NSCLC. Clin Cancer Res; 24(5); 1227–39. ©2017 AACR.

Up-regulated basigin-2 in microglia induced by hypoxia promotes retinal angiogenesis

Retinal microglia cells contribute to vascular angiogenesis and vasculopathy induced by relative hypoxia. However, its concrete molecular mechanisms in shaping retinal angiogenesis have not been elucidated. Basigin, being involved in tumour neovasculogenesis, is explored to exert positive effects on retinal angiogenesis induced by microglia. Therefore, we set out to investigate the expression of basigin using a well‐characterized mouse model of oxygen‐induced retinopathy, which recapitulated hypoxia‐induced aberrant neovessel growth. Our results elucidate that basigin is overexpressed in microglia, which accumulating in retinal angiogenic sprouts. In vitro, conditioned media from microglia BV2 under hypoxia treatment increase migration and tube formation of retinal capillary endothelia cells, compared with media from normoxic condition. The angiogenic capacity of BV2 is inhibited after basigin knockdown by small interfering RNAs. A new molecular mechanism for high angiogenic capacity, whereby microglia cells release basigin via up‐regulation of PI3K‐AKT and IGF‐1 pathway to induce angiogenesis is unveiled. Collectively, our results demonstrate that basigin from hypoxic microglia plays a pivotal pro‐angiogenic role, providing new insights into microglia‐promoting retinal angiogenesis.