Gefitinib analogue V1801 induces apoptosis of T790M EGFR-harboring lung cancer cells by up-regulation of the BH-3 only protein Noxa

Noxa upregulation and 5-gene apoptotic biomarker panel in colorectal cancer

BACKGROUND

NOXA and MCL1 are involved in the intrinsic pathway of apoptosis, where Noxa selectively binds to MCL1 and prevents it from inhibiting apoptosis. Both factors are considered as potential tumour biomarkers, while MCL1 has attracted interest as target in cancer. The purpose of this study was to investigate the expression of NOXA and MCL1 in 160 CRC tumour samples, to investigate their significance, also in combination with IAPs, DR5 expression and KRAS gene mutations in CRC.

MATERIALS AND METHODS

Fresh frozen colorectal tissue was obtained from patients undergoing surgery for CRC. Real-time quantitative PCR was performed for the determination of mRNA expression levels. Protein expression was determined immunohistochemically. Differences in the mRNA expression profile were evaluated with the nonparametric Wilcoxon signed ranks test. Statistical analysis was performed with the use of Mann-Whitney U test and receiver-operating characteristic (ROC) curve.

RESULTS

NOXA was found to be overexpressed in CRC tumours (P < .0001), even from early stage. Moreover, NOXA/MCL1 mRNA expression was significantly elevated in tumour samples compared to normal pairs (P < .0001). ROC curve analysis showed that both NOXA expression and its combination with Mcl1 expression have fair discriminatory value between CRC and normal colorectal tissue. Combinatorial ROC analysis revealed the most significant discriminatory value of NOXA, MCL1 with cIAP1 and cIAP2 (AUC = 0.834, P < .0001) as a 5-gene panel of markers.

CONCLUSION

Noxa, Mcl1, DR5, cIAP1 and cIAP2 mRNA expressions are significantly deregulated in CRC and could provide a panel of markers with significant discriminatory value between CRC and normal colorectal tissue.

Synthesis of novel gefitinib-based derivatives and their anticancer activity

Drug latentiation is a process of modifying a drug molecule structurally to improve its binding affinity as well as increasing the drug-receptor interactions and potentiate its therapeutic potential. In the quest for discovering more potent epidermal growth factor receptor (EGFR) inhibitors, gefitinib-based derivatives were designed by simple structural modification at the secondary amine of gefitinib by N-alkylation. Three gefitinib derivatives (gefitinib-NB, -NP, and -NIP) were synthesized by N-alkylation and phase transfer catalysis. Structural characterization, physicochemical parameters such as solubility, log P, and p K _a were determined. Molecular docking studies were carried out to investigate the binding interactions at the active site. Further drug-bovine serum albumin (BSA) protein and drug-calf thymus (CT) DNA interactions were performed to understand the pharmacokinetics of the synthesized derivatives. All the compounds were screened for preliminary in vitro cytotoxic activity against A549, A431 lung, and MDA-MB-231 breast cancer cell lines by MTT assay. The gefitinib-NP and gefitinib-NB derivatives exhibited strong cytotoxic activity compared with gefitinib. They also showed higher drug-BSA and drug-DNA interactions. Molecular docking studies showed the orientation and binding interactions with the EGFR as well as with BSA and CT DNA. The results establish a strong correlation between the experimental and molecular docking studies. EGFR inhibition studies were also carried out for the derivatives and we identified the NP derivative of gefitinib as a potential lead compound. The gefitinib-based derivatives reported herein are cytotoxic agents and can be tested for further pharmacokinetic profiles and toxicity studies which might be helpful for designing more potent gefitinib-based derivatives in the future.

Gefitinib induces non-small cell lung cancer H1650 cell apoptosis through downregulating tumor necrosis factor-related apoptosis-inducing ligand expression levels

Non-small cell lung cancer (NSCLC) presents severe threats to the lives of patients. Gefitinib is one of the first-line drugs available for the treatment of NSCLC in the clinical setting. The present study investigated the effects of gefitinib on NSCLC H1650 cell viability and apoptosis via MTT assays and flow cytometry. Western blot analysis was employed to detect tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) expression levels in H1650 cells. In the present study, H1650 cells were treated with TRAIL siRNA or an empty plasmid vector control, followed by gefitinib treatment to investigate apoptosis. Gefitinib treatment markedly inhibited H1650 cell viability, induced apoptosis and reduced TRAIL expression levels. TRAIL interference enhanced H1650 cell apoptosis induced by gefitinib. TRAIL overexpression suppressed gefitinib-induced H1650 cell apoptosis. In addition, gefitinib induced NSCLC H1650 cell apoptosis by downregulating TRAIL expression levels.

Synergistic antitumor activity of aspirin and erlotinib: Inhibition of p38 enhanced aspirin plus erlotinib-induced suppression of metastasis and promoted cancer cell apoptosis

High-dose erlotinib is effective for non-small cell lung cancer patients with brain metastases. The aim of the present study was to investigate whether aspirin could increase the anti-proliferative and anti-metastatic effects of regular erlotinib treatment. The data demonstrated that combining aspirin with erlotinib significantly induced apoptosis and inhibited tumor cell proliferation in several human cancer types. Furthermore, aspirin plus erlotinib significantly induced the activation of E-cadherin and suppression of p38. The data also indicated that the p38/E-cadherin pathway may be involved in the apoptosis caused by the combination of aspirin and erlotinib. As p38 and E-cadherin also serve a key role in epithelial-to-mesenchymal transition (EMT) and cancer metastasis, we hypothesized that the combination of aspirin and erlotinib may significantly inhibit tumor metastasis. First, aspirin plus erlotinib achieved potent inhibition of cancer cell migration and invasion, which are crucial for cancer metastasis. Next, the results demonstrated that aspirin plus erlotinib inhibited angiogenesis by suppressing endothelial cell migration and invasion. Moreover, it was confirmed that aspirin plus erlotinib exerted synergistic anti-angiogenic effects. Finally, the synergistic anti-proliferative and anti-metastatic effects of the combination of aspirin with erlotinib were further validated in an A549 xenograft model in vivo. In conclusion, aspirin plus erlotinib may be an effective combination regimen for patients with metastatic cancer.

Arenobufagin Induces Apoptotic Cell Death in Human Non-Small-Cell Lung Cancer Cells via the Noxa-Related Pathway

Arenobufagin, an active component isolated from the traditional Chinese medicine Chan Su, exhibits anticancer influences in several human malignancies. However, the effects and action mechanisms of arenobufagin on non-small-cell lung cancer (NSCLC) are still unknown. In this study, we reported that arenobufagin acted through activation of Noxa-related pathways and promoted apoptotic cell death in human NSCLC cells. Our results revealed that arenobufagin-induced apoptosis was caspase-dependent, as evidenced by the fact that caspase-9, caspase-3 and poly (ADP-ribose) polymerase (PARP) were cleaved, and pretreatment with a pan-caspase inhibitor Z-VAD-FMK inhibited the pro-apoptosis effect of arenobufagin. Mechanistically, we further found that arenobufagin rapidly upregulated the expression of the pro-apoptosis protein Noxa, and abrogated the anti-apoptosis protein Mcl-1, a major binding partner of Noxa in the cell. More importantly, the knockdown of Noxa greatly blocked arenobufagin-induced cell death, highlighting the contribution of this protein in the anti-NSCLC effects of arenobufagin. Interestingly, arenobufagin also increased the expression of p53, a direct transcriptional activator for the upregulation of the Noxa protein. Taken together, our results suggest that arenobufagin is a potential anti-NSCLC agent that triggers apoptotic cell death in NSCLC cells through interfering with the Noxa-related pathway.

Expression of cancerous inhibitor of protein phosphatase 2A in human triple negative breast cancer correlates with tumor survival, invasion and autophagy

Cancerous inhibitor of protein phosphatase 2A (CIP2A) is a recently characterized oncoprotein which is involved in the progression of several human malignancies. The present study aimed to investigate its biological function in human triple negative breast cancer (TNBC). The expression of CIP2A in TNBC cells was examined and it was observed that CIP2A was elevated in the TNBC cell line compared with poorly invasive breast cancer cells. CIP2A depletion in TNBC cell lines inhibited proliferation, and induced apoptosis and autophagy. In addition, CIP2A depletion inhibited invasion and migration of TNBC cells. Furthermore, CIP2A depletion downregulated Akt/mTOR/P70S6K phosphorylation. These results validate the role of CIP2A as a invasion-associated oncoprotein and established CIP2A as a promising therapeutic target of TNBC.

Oridonin inhibits gefitinib-resistant lung cancer cells by suppressing EGFR/ERK/MMP-12 and CIP2A/Akt signaling pathways

Oridonin (Ori), a diterpenoid compound extracted from traditional medicinal herbs, elicits antitumor effects on many cancer types. However, whether Ori can be used in gefitinib-resistant non-small cell lung cancer (NSCLC) cells remains unclear. This study investigated the antitumor activity and underlying mechanisms of Ori. Results demonstrated that this compound dose-dependently inhibited the proliferation, invasion, and migration of the gefitinib-resistant NSCLC cells in vitro. Ori also significantly downregulated the phosphorylation of EGFR, ERK, Akt, expression levels of matrix metalloproteinase-12 (MMP-12), and the cancerous inhibitor of protein phosphatase 2A (CIP2A). In addition, Ori upregulated protein phosphatase 2A (PP2A) activity of gefitinib-resistant NSCLC cells. Ori combined with docetaxel synergistically inhibited these cells. Ori also inhibited tumor growth in murine models. Immunohistochemistry results further revealed that Ori downregulated phospho-EGFR, MMP-12, and CIP2A in vivo. These findings indicated that Ori can inhibit the proliferation, invasion, and migration of gefitinib-resistant NSCLC cells by suppressing EGFR/ERK/MMP-12 and CIP2A/PP2A/Akt signaling pathways. Thus, Ori may be a novel effective candidate to treat gefitinib-resistant NSCLC.

A NOXA/MCL-1 Imbalance Underlies Chemoresistance of Malignant Rhabdoid Tumor Cells

Malignant rhabdoid tumor (MRT) is a rare aggressive pediatric cancer characterized by inactivation of SNF5, a core subunit of SWI/SNF complexes. Previously, we showed that SNF5 contributes to transcriptional activation of NOXA, a pro-apoptotic protein that binds and inhibits the anti-apoptotic protein MCL-1. In this study, we found that NOXA expression was downregulated in MRT cell lines as well as in clinical MRT samples and that ectopically expressed NOXA bound MCL-1 and increased the sensitivity of MRT cell lines to doxorubicin (DOX) by promoting apoptosis. Consistent with this finding, knockdown of MCL-1 in MRT cell lines induced apoptosis and increased DOX sensitivity in MRT cells, and the MCL-1 inhibitor TW-37 synergized with DOX to induce MRT cell death. Our results suggest that modulation of the NOXA/MCL-1 pathway may be a potential strategy for the treatment of patients with MRT. J. Cell. Physiol. 231: 1932-1940, 2016. © 2015 Wiley Periodicals, Inc.

Porphine functionalized nanoparticles of star-shaped poly(ε-caprolactone)-b-D-α-tocopheryl polyethylene glycol 1000 succinate biodegradable copolymer for chemophotodynamic therapy on cervical cancer

We developed a system of biodegradable nanoparticles (NPs) of 5,10,15,20-tetrakis(4-aminophenyl)-21H,23H-porphine (TAPP) centered, 4 arm star-shaped copolymers based on poly(ε-caprolactone) (PCL) and D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) for combinatory chemophotodynamic therapy by using docetaxel (DTX) as a model anticancer drug and TAPP as photodynamic sensitizer. TPGS component in the copolymer plays an important role in enhancing the drug encapsulation efficiency, drug release kinetics and cellular uptake of the NPs, as well as in overcoming the multidrug resistance due to inhibition of P-glycoproteins (P-gp) of the cancer cells. We demonstrated in vitro by using the MCF7/ADR breast cancer cells of P-gp overexpression and the HeLa cervical cancer cells that the proposed chemophotodynamic therapy by the DTX-loaded TAPP-PCL-b-TPGS NPs could have much higher therapeutic effect than the original drug Taxotere®. IC50 data showed that the DTX-loaded TAPP-PCL-b-TPGS NPs chemophotodynamic therapy could be 9.36 and 56.5-fold efficient after 24 and 48h treatment, respectively in comparison with the Taxotere® chemotherapy. The in vivo investigation by employing a cervical cancer xenograft model further confirmed the advantages of the proposed chemophotodynamic therapy by the DTX-loaded TAPP-PCL-b-TPGS NPs versus the Taxotere® chemotherapy.

Homoharringtonine induces apoptosis and inhibits STAT3 via IL-6/JAK1/STAT3 signal pathway in Gefitinib-resistant lung cancer cells

Tyrosine kinase inhibitors (TKIs) are mostly used in non-small cell lung cancer (NSCLC) treatment. Unfortunately, treatment with Gefitinib for a period of time will result in drug resistance and cause treatment failure in clinic. Therefore, exploring novel compounds to overcome this resistance is urgently required. Here we investigated the antitumor effect of homoharringtonine (HHT), a natural compound extracted from Cephalotaxus harringtonia, on Gefitinib-resistant NSCLC cell lines in vitro and in vivo. NCI-H1975 cells with EGFR T790M mutation are more sensitive to HHT treatment compared with that of A549 cells with wild type EGFR. HHT inhibited cells growth, cell viability and colony formation, as well as induced cell apoptosis through mitochondria pathway. Furthermore, we explored the mechanism of HHT inhibition on NSCLC cells. Higher level of interleukin-6 (IL-6) existed in lung cancer patients and mutant EGFR and TGFβ signal requires the upregulation of IL-6 through the gp130/JAK pathway to overactive STAT3, an oncogenic protein which has been considered as a potential target for cancer therapy. HHT reversiblely inhibited IL-6-induced STAT3 Tyrosine 705 phosphorylation and reduced anti-apoptotic proteins expression. Gefitinib-resistant NSCLC xenograft tests also confirmed the antitumor effect of HHT in vivo. Consequently, HHT has the potential in Gefitinib-resistant NSCLC treatment.

The natural compound magnolol inhibits invasion and exhibits potential in human breast cancer therapy

Invasion and metastasis are the main causes of treatment failure and death in breast cancer. Thus, novel invasion-based therapies such as those involving natural agents are urgently required. In this study, we examined the effects of magnolol (Mag), a compound extracted from medicinal herbs, on breast cancer cells in vitro and in vivo. Highly invasive cancer cells were found to be highly sensitive to treatment. Mag markedly inhibited the activity of highly invasive MDA-MB-231 cells. Furthermore, Mag significantly downregulated matrix metalloproteinase-9 (MMP-9) expression, an enzyme critical to tumor invasion. Mag also inhibited nuclear factor-κB (NF-κB) transcriptional activity and the DNA binding of NF-κB to MMP-9 promoter. These results indicate that Mag suppresses tumor invasion by inhibiting MMP-9 through the NF-κB pathway. Moreover, Mag overcame the promoting effects of phorbol 12-myristate 13-acetate (PMA) on the invasion of MDA-MB-231 cells. Our findings reveal the therapeutic potential and mechanism of Mag against cancer.