Overexpression of Bax induces apoptosis and enhances drug sensitivity of hepatocellular cancer-9204 cells

Two staged phase II clinical trial of Eribulin monotherapy in advanced or recurrent cervical cancer

BACKGROUND

Eribulin a microtubule targeting agent and analog of Halichondrin B, a natural product isolated from marine sponge H. okadai, has proven clinical efficacy in metastatic pretreated breast cancer and liposarcoma. We conducted a 2-stage Phase II study of eribulin in patients with advanced/recurrent cervical cancer to examine its clinical activity and evaluate biomarkers for predictors of response.

METHODS

Women with advanced/recurrent cervical cancer after ≤1 prior chemotherapy regimen, measurable disease and ECOG performance status ≤2 were treated with eribulin (1.4 mg/m² IV day 1 and 8, every 21 days) with tumor assessments every 2 cycles. Primary endpoint was 6-month progression-free survival (PFS6); secondary were best overall response (RECISTv1.1), toxicity (CTCAEv4.03) and overall survival (OS). Exploratory endpoints were associations of biomarkers with clinical activity. Immunohistochemistry was performed on archival tumor samples. Overexpression was defined when both intensity and distribution scores were ≥ 2.

RESULTS

32 patients enrolled from 11/2012-5/2017. 29/32 patients had prior chemotherapy with cisplatin/paclitaxel/bevacizumab (n = 12) or cisplatin/gemcitabine (n = 12) as the most common regimens. 14 patients received prior paclitaxel. 1 (3%) had a complete response, 5 (16%) had a partial response and 13 (41%) had stable disease for ORR of 19% (95% CI 8, 37). Those who are paclitaxel naïve experienced the greatest benefit with a 29% ORR (95% CI 12, 54). Patients who received prior paclitaxel responded less favorably than those who did not (p = .002) and had a shorter PFS and OS. Grade 3/4 adverse events occurring in >10% of patients were anemia (n = 12, 38%), neutropenia (n = 7, 22%) and leukopenia (n = 6, 19%). Analysis of correlative predictors of response revealed that patients who did not overexpress βII and BAX were significantly more likely to respond to e`ribulin. PFS was significantly shorter in patients with βII and BAX overexpression, OS was significantly shorter in those with βIII and BAX overexpression. These associations remained after multivariate analysis.

CONCLUSIONS

Eribulin shows modest activity in patients with recurrent/advanced cervical cancer with a favorable toxicity profile. Prior paclitaxel exposure is associated with decreased eribulin response. βII, βIII tubulin subtypes and BAX are predictors of response and survival. Eribulin may be an option for women with paclitaxel-naïve recurrent/advanced cervical cancer.

Low-dose spironolactone ameliorates adipose tissue inflammation and apoptosis in letrozole-induced PCOS rat model

BACKGROUND OF STUDY

Globally, many reproductive aged women are affected by polycystic ovarian syndrome (PCOS), which is a common endocrine and metabolic disorder that is linked with adipose dysfunction and chronic low-grade inflammation. Spironolactone (SPL), a mineralocorticoid receptor blocker has been documented as a metabolic modulator. However, its immunomodulatory effect in PCOS is unknown. Therefore, the present study hypothesized that SPL would ameliorate adipose dysfunction and inflammation in experimental PCOS animals.

MATERIALS AND METHODS

Female Wistar rats that were 8 weeks old were allocated into three groups. Group 1 received vehicle (distilled water; p.o.), group 2 received letrozole (1 mg/kg; p.o.) and group 3 received letrozole plus SPL (0.25 mg/kg, p.o.). The administration was performed once daily for 21 days.

RESULTS

The experimental PCOS animals showed insulin resistance, hyperinsulinemia and hyperandrogenism as well as oxidative stress and elevated inflammatory biomarkers (NF-kB/TNF-/IL-6) as well as a significant decrease in triglycerides, total cholesterol, free fatty acids, GSH and G6PD in the adipose tissue of PCOS animals. In addition, immunohistochemical assessment of adipose tissue showed significant expression of BAX and inflammasome, indicating apoptosis and inflammation compared to control animals. Nevertheless, administration of SPL attenuated these perturbations.

CONCLUSION

Altogether, the present study suggests that low-dose spironolactone confers protection against adipose dysfunction in experimental PCOS animals by attenuating inflammation, oxidative stress and cellular apoptosis.

The Protection of Zinc against Acute Cadmium Exposure: A Morphological and Molecular Study on a BBB In Vitro Model

Cadmium (Cd) is a well-known occupational and environmental pollutant worldwide, and its toxicity is widely recognised. Cd is reported to increase the permeability of the blood–brain barrier (BBB) and to penetrate and accumulate in the brain. Although many lines of evidence show that Cd toxicity is induced by different mechanisms, one of the best known is the Cd-dependent production of reactive oxygen species (ROS). Zinc is a trace element known as coenzyme and cofactor for many antioxidant proteins, such as metallothioneins and superoxide dismutase enzymes. To date, very little is known about the role of Zn in preventing Cd-induced blood–brain barrier (BBB) alterations. The goal of this study was to test the Zn antioxidant capacity against Cd-dependent alterations in a rat brain endothelial cell line (RBE4), as an in vitro model for BBB. In order to mimic acute Cd poisoning, RBE4 cells were treated with CdCl₂ 30 µM for 24 h. The protective role of ZnCl₂ (50 µM) was revealed by evaluating the cell viability, reactive oxygen species (ROS) quantification, cytochrome C distribution, and the superoxide dismutase (SOD) protein activity. Additionally, the effectiveness of Zn in counteracting the Cd-induced damage was investigated by evaluating the expression levels of proteins already known to be involved in the Cd signalling pathway, such as GRP78 (an endoplasmic reticulum (ER) stress protein), caspase3 pro- and cleaved forms, and BAX. Finally, we evaluated if Zn was able to attenuate the alterations of zonula occludens-1 (ZO-1), one of the tight-junction (TJ) proteins involved in the formation of the BBB. Our data clearly demonstrate that Zn, by protecting from the SOD activity impairment induced by Cd, is able to prevent the triggering of the Cd-dependent signalling pathway that leads to ZO-1 dislocation and downregulation, and BBB damage.

C5, A Cassaine Diterpenoid Amine, Induces Apoptosis via the Extrinsic Pathways in Human Lung Cancer Cells and Human Lymphoma Cells

Apoptosis pathways in cells are classified into two pathways: the extrinsic pathway, mediated by binding of the ligand to a death receptor and the intrinsic pathway, mediated by mitochondria. Apoptosis is regulated by various proteins such as Bcl-2 (B-cell lymphoma 2) family and cellular FLICE (Fas-associated Death Domain Protein Interleukin-1β-converting enzyme)-inhibitory protein (c-FLIP), which have been reported to inhibit caspase-8 activity. In this study, it was found that C5 (3β-Acetyl-nor-erythrophlamide), a compound of cassaine diterpene amine from Erythrophleum fordii, induced cell apoptosis in a variety of types of cancer cells. Induction of apoptosis in cancer cells by C5 was inversely related to the level of Bcl-2 expression. Overexpression of Bcl-2 into cancer cells significantly decreased C5-induced apoptosis. It was also found that treatment of cancer cells with a caspase-8 inhibitor significantly suppressed C5-induced apoptosis; however, treatment with caspase-9 inhibitors did not affect C5-induced apoptosis, suggesting that C5 may induce apoptosis via the extrinsic pathway by activating caspase-8. It was confirmed that treatment with C5 alone induced an association of FADD with procaspase-8; however, overexpression of c-FLIP decreased C5-induced caspase-8 activation. In conclusion, C5 could be utilized as a new useful lead compound for the development of an anti-cancer agent that has the goal of apoptosis.

Designing combination therapies with modeling chaperoned machine learning

Chemotherapy resistance is a major challenge to the effective treatment of cancer. Thus, a systematic pipeline for the efficient identification of effective combination treatments could bring huge biomedical benefit. In order to facilitate rational design of combination therapies, we developed a comprehensive computational model that incorporates the available biological knowledge and relevant experimental data on the life-and-death response of individual cancer cells to cisplatin or cisplatin combined with the TNF-related apoptosis-inducing ligand (TRAIL). The model's predictions, that a combination treatment of cisplatin and TRAIL would enhance cancer cell death and exhibit a "two-wave killing" temporal pattern, was validated by measuring the dynamics of p53 accumulation, cell fate, and cell death in single cells. The validated model was then subjected to a systematic analysis with an ensemble of diverse machine learning methods. Though each method is characterized by a different algorithm, they collectively identified several molecular players that can sensitize tumor cells to cisplatin-induced apoptosis (sensitizers). The identified sensitizers are consistent with previous experimental observations. Overall, we have illustrated that machine learning analysis of an experimentally validated mechanistic model can convert our available knowledge into the identity of biologically meaningful sensitizers. This knowledge can then be leveraged to design treatment strategies that could improve the efficacy of chemotherapy.

Counteraction of Apoptotic and Inflammatory Effects of Adriamycin in the Liver Cell Culture by Clinopitolite

Growing evidence has been reported on adriamycin (ADR) hepatotoxicity in literature. Hepatotoxicity caused by the use of drugs has a serious undesirable effect in the cure of cancer patients that needs to be eliminated. The exact mechanism of ADR on non-cancerous tissue still remains to be a mystery. The zeolite (clinoptilolite) minerals form a complex group of aluminosilicates that often occur as accessory minerals in intermediate and basic rocks. In light of this information, we investigated the possible anti-inflammatory and anti-apoptotic effects of clinoptilolite in ADR that is inducing the toxicity in primary liver cell culture. Primary liver cell culture from rat was used in the study. We had three experiment groups including the following: (1) cells treated only with 50 μM ADR for 24 h, (2) cells treated with the 50 μM ADR for 24 h and then treated with 10(-4) M zeolite for 1 h, and (3) cells were incubated with 50 μM ADR for 24 h and then incubated with 10(-4) M zeolite for 24 h to test its long-term effects. After that, western blotting was performed in order to evaluate protein expression levels of several inflammation markers including IL-1β, tumor necrosis factor (TNF)-α, and nuclear factor kappa B (NF-κB), and immunohistochemistry was carried out to detect apoptosis in liver cell culture. Also, TdT-dUTP Terminal Nick-End Labeling (TUNEL) method was used for detecting apoptosis. We found elevated levels of inflammatory protein and apoptotic markers in ADR-administered cells (p < 0.05). Inflammatory and apoptotic markers decreased significantly after treated with zeolite (p < 0.05). The present study was pointed out that ADR causes hepatotoxicity via apoptosis and/or inflammation processes resulting from initiator NF-κB and TNF which causes proinflammatory mediators such as IL-1β. Elevation of inflammation might give rise to trigger apoptosis. Clinoptilolite counteracted the apoptosis and inflammation induced by ADR arising from the decrease in NF-κB, TNF-α, and IL-1β protein levels.

ChBax/Bak as key regulators of the mitochondrial apoptotic pathway: cloned and characterized in Crassostrea hongkongensis

Apoptosis has been primarily investigated in mammals, and little is known about apoptosis in mollusks. The proteins Bax and Bak play critical roles in the mitochondrial apoptosis pathway and in determining cell fate. In this study, ChBax and ChBak, homologs of the well-known Bax and Bak proteins, were identified from the oyster Crassostrea hongkongensis. The ChBax/Bak proteins consist of 207/232 amino acids with the typical domains found in BCL-2 family members. ChBax and ChBak mRNA expression were detected in all 8 of the selected oyster tissues and at the different stages of development. Fluorescence microscopy revealed that the full-length proteins of ChBax/Bak were located in the cytoplasm and mitochondrial outer membrane, of HEK293T cells, respectively. Furthermore, both of the genes' expression levels were found to increase in the hemocytes of oysters challenged with pathogens. The over-expression of ChBax or ChBak activates the p53-Luc reporter gene in HEK293T cells in a dose-dependent manner. These results indicate that ChBax and ChBak may play important roles in the mitochondrial apoptotic pathway in oysters.

In silico regulatory analysis for exploring human disease progression

Background

An important goal in bioinformatics is to unravel the network of transcription factors (TFs) and their targets. This is important in the human genome, where many TFs are involved in disease progression. Here, classification methods are applied to identify new targets for 152 transcriptional regulators using publicly-available targets as training examples. Three types of sequence information are used: composition, conservation, and overrepresentation.

Results

Starting with 8817 TF-target interactions we predict an additional 9333 targets for 152 TFs. Randomized classifiers make few predictions (~2/18660) indicating that our predictions for many TFs are significantly enriched for true targets. An enrichment score is calculated and used to filter new predictions.

Two case-studies for the TFs OCT4 and WT1 illustrate the usefulness of our predictions:

• Many predicted OCT4 targets fall into the Wnt-pathway. This is consistent with known biology as OCT4 is developmentally related and Wnt pathway plays a role in early development.

• Beginning with 15 known targets, 354 predictions are made for WT1. WT1 has a role in formation of Wilms' tumor. Chromosomal regions previously implicated in Wilms' tumor by cytological evidence are statistically enriched in predicted WT1 targets. These findings may shed light on Wilms' tumor progression, suggesting that the tumor progresses either by loss of WT1 or by loss of regions harbouring its targets.

• Targets of WT1 are statistically enriched for cancer related functions including metastasis and apoptosis. Among new targets are BAX and PDE4B, which may help mediate the established anti-apoptotic effects of WT1.

• Of the thirteen TFs found which co-regulate genes with WT1 (p ≤ 0.02), 8 have been previously implicated in cancer. The regulatory-network for WT1 targets in genomic regions relevant to Wilms' tumor is provided.

Conclusion

We have assembled a set of features for the targets of human TFs and used them to develop classifiers for the determination of new regulatory targets. Many predicted targets are consistent with the known biology of their regulators, and new targets for the Wilms' tumor regulator, WT1, are proposed. We speculate that Wilms' tumor development is mediated by chromosomal rearrangements in the location of WT1 targets.

Reviewers

This article was reviewed by Trey Ideker, Vladimir A. Kuznetsov(nominated by Frank Eisenhaber), and Tzachi Pilpel.

Melanoma Antigen A4 Is Expressed in Non–Small Cell Lung Cancers and Promotes Apoptosis

A variety of melanoma antigen A (MAGE-A) genes are commonly detected in non-small cell lung cancers. Their biological function is not well characterized but may involve the regulation of apoptosis and cell cycle progression. We hypothesized that MAGE-A4 is involved in the regulation of apoptosis. To investigate this, expression of MAGE-A was evaluated. MAGE-A4 was expressed in 48% of non-small cell lung carcinomas. Ninety percent of lung carcinomas expressing MAGE-A4 were classified as squamous cell carcinomas and 10% were adenocarcinomas. Tumor-free surrounding lung tissue was negative for MAGE-A4. A molecular clone of MAGE-A4 derived from human lung cancer was stably expressed in human embryonic kidney cells (293 cells) to evaluate effects on cell death. Overexpression of MAGE-A4 increased apoptosis as measured by the apoptotic index (P < 0.0001) and caspase-3 activity (P < 0.002). Exposure to 25 micromol/L etoposide, a chemotherapeutic agent, increased the apoptotic effect (P < 0.0001). Furthermore, we show that MAGE-A4 silencing using a small interfering RNA approach results in decreased caspase-3 activity in the squamous cell lung cancer cell line H1703 by 58% (P = 0.0027) and by 24% (P = 0.028) in 293/MAGE-A4 cells. These findings suggest that MAGE-A4 expression may promote tumor cell death, sensitize malignancies to apoptotic stimuli, such as chemotherapeutic agents, and therefore may represent a tumor suppressor protein.