The Combination of Omega-3 Stearidonic Acid and Docetaxel Enhances Cell Death over Docetaxel Alone in Human Prostate Cancer Cells

Augmentation of Docetaxel-Induced Cytotoxicity in Human PC-3 Androgen-Independent Prostate Cancer Cells by Combination With Four Natural Apoptosis-Inducing Anticancer Compounds

Docetaxel (DTX) is the treatment of choice for metastatic castration-resistant prostate cancer. However, developing drug resistance is a significant challenge for achieving effective therapy. This study evaluated the anticancer and synergistic effects on DTX of four natural compounds (calebin A, 3^'-hydroxypterostilbene, hispolon, and tetrahydrocurcumin) using PC-3 androgen-resistant human prostate cancer cells. We utilized the CellTiter-Glo^® luminescent cell viability assay and human PC-3 androgen-independent prostate cancer cells to determine the antiproliferative effects of the four compounds alone and combined with DTX. Cytotoxicity to normal human prostate epithelial cells was tested in parallel using normal immortalized human prostate epithelial cells (RWPE-1). We used cell imaging and quantitative caspase-3 activity to determine whether these compounds induce apoptosis. We also measured the capacity of each drug to inhibit TNF-α-induced NF-kB using a colorimetric assay. Our results showed that all four natural compounds significantly augmented the toxicity of DTX to androgen-resistant PC-3 prostate cancer cells at IC₅₀. Interestingly, when used alone, each of the four compounds had a higher cytotoxic activity to PC-3 than DTX. Mechanistically, these compounds induced apoptosis, which we confirmed by cell imaging and caspase-3 colorimetric assays. Further, when used either alone or combined with DTX, the four test compounds inhibited TNF-α-induced NF-kB production. More significantly, the cytotoxic effects on normal immortalized human prostate epithelial cells were minimal and non-significant, suggesting prostate cancer-specific effects. In conclusion, the combination of DTX with the four test compounds could effectively enhance the anti-prostate cancer activity of DTX. This combination has the added value of reducing the DTX effective concentration. We surmise that calebin A, 3^'-hydroxypterostilbene, hispolon, and tetrahydrocurcumin were all excellent drug candidates that produced significant antiproliferative activity when used alone and synergistically enhanced the anticancer effect of DTX. Further in vivo studies using animal models of prostate cancer are needed to confirm our in vitro findings.

Prediction of response and adverse drug reaction of pemetrexed plus platinum-based chemotherapy in lung adenocarcinoma by serum metabolomic profiling

•

Oncologists need effective tools to predict and improve their treatment outcome.

•

We assessed the performance of a metabolomics approach to predict the response and toxicity to pemetrexed plus platinum-based chemotherapy in lung adenocarcinoma.

•

We established effective and convenient models that can predict the efficacy and toxicity of pemetrexed plus platinum chemotherapy in lung adenocarcinoma patients before treatment delivery.

Background

Pemetrexed plus platinum doublet chemotherapy regimen remains to be the standard first-line treatment for lung adenocarcinoma patients. However, few biomarkers can be used to identify potential beneficiaries with maximal efficacy and minimal toxicity. This study aimed to explore potential biomarker models predictive of efficacy and toxicity after pemetrexed plus platinum chemotherapy based on metabolomics profiling.

Methods

A total of 144 patients who received at least two cycles of pemetrexed plus platinum chemotherapy were enroled in the study. Serum samples were collected before initial treatment to perform metabolomics profiling analysis. Logistic regression analysis was performed to establish prediction models.

Results

157 metabolites were found to be differentially expressed between the response group and the nonresponse group. A panel of Phosphatidylserine 20:4/20:1, Sphingomyelin d18:1/18:0, and Phosphatidic Acid 18:1/20:0 could predict pemetrexed and platinum chemotherapy response with an Area Under the Receiver Operating Characteristic curve (AUROC) of 0.7968. 76 metabolites were associated with hematological toxicity of pemetrexed plus platinum chemotherapy. A panel incorporating triglyceride 14:0/22:3/22:5, 3-(3-Hydroxyphenyl) Propionate Acid, and Carnitine C18:0 was the best predictive ability of hematological toxicity with an AUROC of 0.7954. 54 differential expressed metabolites were found to be associated with hepatotoxicity of pemetrexed plus platinum chemotherapy. A model incorporating stearidonic acid, Thromboxane B3, l-Homocitrulline, and phosphoinositide 20:3/18:0 showed the best predictive ability of hepatotoxicity with an AUROC of 0.8186.

Conclusions

This study established effective and convenient models that can predict the efficacy and toxicity of pemetrexed plus platinum chemotherapy in lung adenocarcinoma patients before treatment delivery.

Combinatorial effects of telmisartan and docetaxel on cell viability and metastatic gene expression in human prostate and breast cancer cells

The epithelial-to-mesenchymal transition (EMT) is a unique process resulting in enhanced cell motility, invasiveness, and metastasis in cancer. The EMT is regulated by several transcription factors, including Snail and Slug, which exert crucial roles during cancer progression. We have studied the effects of Docetaxel as the first-line chemotherapy agent for prostate cancer, and Telmisartan as an anti-hypertensive drug on the expression level of Snail and Slug. In addition, the effects of Docetaxel, Telmisartan and their combination on cancer cell proliferation were investigated. The PC3, DU145, MDA-MB468, and HEK cell lines were used for this study. Quantitative RT-PCR analysis and MTT assay were used to study the expression of Snail and Slug level and cell proliferative assay, respectively. We found that a combination of Docetaxel + Telmisartan effectively inhibits the cell proliferation in cancerous cells in comparison with each drug alone (P<0.05). Furthermore, in these cell lines, Docetaxel, Telmisartan and their combination significantly diminished the expression level of Snail and Slug genes compared to control cells (P<0.001), however, in the HEK cell line, this effect was seen only in the combination group. Our data imply that Telmisartan and its combination with Docetaxel exert strong inhibitory effects on the expression level of Snail and Slug genes. Also, these drugs and their combination could inhibit cancer cell proliferation. In conclusion, the combination of Telmisartan and Docetaxel has the potential to suppress the metastasis of prostate and breast cancer cells.

Oncolytic adenovirus carrying SPAG9-shRNA enhanced the efficacy of docetaxel for advanced prostate cancer

BACKGROUND

Sperm-associated antigen 9 (SPAG9) is closely related to the growth and metastasis of advanced prostate cancer. Docetaxel (DTX) is the gold standard for chemotherapy of prostate cancer, but its side effects decrease the life quality of patients. Therefore, it is urgent to develop combination therapy to increase chemotherapy efficacy for advanced prostate cancer.

METHODS

Oncolytic adenovirus carrying a short hairpin RNA (shRNA) targeting SPAG9 (ZD55-shSPAG9) was applied alone or in combination with docetaxel in prostate cancer cells. Cells were analyzed by cell counting kit-8, Hocehst-33258, transwell and western blot analysis. For in vivo experiments, nude mice were loaded with prostate cancer cells.

RESULTS

ZD55-shSPAG9 effectively silenced the expression of SPAG9 in prostate cancer cells in vitro and in vivo. The replication of ZD55-shSPAG9 in prostate cancer cells was not affected by docetaxel, but the combined use of ZD55-shSAPAG9 and docetaxel has a better inhibitory effect on tumor growth and invasion in vitro and in vivo.

CONCLUSIONS

Our study showed that the combined use of ZD55-shSPAG9 and docetaxel may be a new approach to the treatment of advanced prostate cancer.

Effects of Low-Intensity Pulsed Ultrasound on Myelosuppression of Rats Induced by Chemotherapy Drugs With Cell Cycle Specificity

OBJECTIVES

To explore the ameliorating effects of low-intensity pulsed ultrasound (LIPUS) on Sprague Dawley rat myelosuppression induced by cell cycle specificity drugs (docetaxel, mitotic phase sensitive; and etoposide, gap 2 phase sensitive).

METHODS

Rats were respectively administered docetaxel (100 mg/kg) or etoposide (110 mg/kg) by intraperitoneal injection for 4 consecutive days. Then the rats were divided randomly into a LIPUS group and a non-LIPUS group. In the LIPUS group, the right femoral metaphysis of rats was treated by LIPUS (acoustic intensity, 200 mW/cm² ; frequency, 0.3 MHz; and duty cycle, 20%) for 20 minutes on 7 consecutive days from day 5. The rats of the non-LIPUS group were treated without ultrasound output. A blood cell count, an enzyme-linked immunosorbent assay, a real-time quantitative polymerase chain reaction, and hematoxylin-eosin staining were applied to detect the results.

RESULTS

Low-intensity pulsed ultrasound significantly promoted the counts of bone marrow nucleated cells, white blood cells, immunoglobulin A (IgA), IgG, granulocyte colony-stimulating factor, stem cell factor, and intercellular cell adhesion molecule 1 and reduced the counts of vascular cell adhesion molecule 1 whether in the docetaxel or etoposide group (P < .05). Low-intensity pulsed ultrasound only increased the expression level of IgM in the docetaxel group but decreased the level of interleukin 6 in the etoposide group (P < .05).

CONCLUSIONS

Low-intensity pulsed ultrasound has potential to be a noninvasive treatment for myelosuppression caused by different cell cycle-sensitive chemotherapy drugs.

Disentangling the environmental processes responsible for the world's largest farmed fish-killing harmful algal bloom: Chile, 2016

The dictyochophyte microalga Pseudochattonella verruculosa was responsible for the largest farmed fish mortality ever recorded in the world, with losses for the Chilean salmon industry amounting to US$ 800 M in austral summer 2016. Super-scale climatic anomalies resulted in strong vertical water column stratification that stimulated development of a dynamic P. verruculosa thin layer (up to 38 μg chl a L^-1) for several weeks in Reloncaví Sound. Hydrodynamic modeling (MIKE 3D) indicated that the Sound had extremely low flushing rates (between 121 and 200 days) in summer 2016. Reported algal cell densities of 7000-20,000 cells mL^-1 generated respiratory distress in fish that was unlikely due to low dissolved oxygen (permanently >4 mg L^-1). Histological examination of salmon showed that gills were the most affected organ with significant tissue damage and circulatory disorders. It is possible that some of this damage was due to a diatom bloom that preceded the Pseudochattonella event, thereby rendering the fish more susceptible to Pseudochattonella. No correlation between magnitude of fish mortality and algal cell abundance nor fish age was evident. Algal cultures revealed rapid growth rates and high cell densities (up to 600,000 cells mL^-1), as well as highly complex life cycle stages that can be easily overlooked in monitoring programs. In cell-based bioassays, Chilean P. verruculosa was only toxic to the RTgill-W1 cell line following exposures to high cell densities of lysed cells (>100,000 cells mL^-1). Fatty acid profiles of a cultured strain showed elevated concentrations of potentially ichthyotoxic, long-chain polyunsaturated fatty acids (PUFAs) (69.7% ± 1.8%)- stearidonic (SDA, 18:4ω3-28.9%), and docosahexaenoic acid (DHA, 22:6ω3-22.3%), suggesting that lipid peroxidation may help to explain the mortalities, though superoxide production by Pseudochattonella was low (< 0.21 ± 0.19 pmol O₂^- cell^-1 h^-1). It therefore remains unknown what the mechanisms of salmon mortality were during the Pseudochattonella bloom. Multiple mitigation strategies were used by salmon farmers during the event, with only delayed seeding of juvenile fish into the cages and towing of cages to sanctuary sites being effective. Airlift pumping, used effectively against other fish-killing HABs in the US and Canada was not effective, perhaps because it brought subsurface layers of Pseudochattonella to the surface, or and it also may have lysed the fragile cells, rendering them more lethal. The present study highlights knowledge gaps and inefficiency of contingency plans by the fish farming industry to overcome future fish-killing algal blooms under future climate change scenarios. The use of new technologies based on molecular methods for species detection, good farm practices by fish farms, and possible mitigation strategies are discussed.

The nicotinamide phosphoribosyltransferase antagonist FK866 inhibits growth of prostate tumour spheroids and increases doxorubicin retention without changes in drug transporter and cancer stem cell protein expression

Nicotinamide phosphoribosyltransferase (NAMPT) is a rate-limiting enzyme for nicotinamide adenine dinucleotide (NAD) synthesis and is involved in cancer cell proliferation through regulation of energy production pathways. Therefore, NAMPT inhibitors are promising drugs for cancer therapy by limiting energy supply of tumours. Herein, we demonstrated that the NAMPT inhibitor FK866 ((E)-N-(4-(1-Benzoylpiperidin-4-yl)butyl)-3-(pyridin-3-yl)acrylamide) dose-dependently inhibited growth and cell motility of DU-145 prostate tumour spheroids and decreased the intracellular ATP concentration. The apoptosis marker cleaved caspase-3 remained unchanged, but the autophagy marker microtubule-associated protein 1A/1B-light chain 3 (LC3) was upregulated. Growth inhibition was reversed upon co-administration of NAD to the cell culture medium. FK866 decreased calcein as well as pheophorbide A efflux from tumour spheroids and increased doxorubicin toxicity, indicating interference with function of drug efflux transporters. DU-145 multicellular tumour spheroids expressed the stem cell associated markers CD133, CD44, Oct4, Nanog, Sox2, and drug transporters ABCB1, ABCG2, and ABCC1 which are associated with stem cell properties in cancer cells. The ABCB1 inhibitor zosuquidar, the ABCG2 inhibitor Ko143, and the ABCC1 inhibitor MK571 increased calcein retention. Neither protein expression of stem cell markers, nor drug transporters was significantly changed upon FK866 treatment. In conclusion, our data suggest that FK866 inhibits prostate cancer cell proliferation by interference with the energy metabolism, and function of drug efflux transporters.

Plant-based stearidonic acid as sustainable source of omega-3 fatty acid with functional outcomes on human health

Dietary omega-3 long chain polyunsaturated fatty acids (n-3 LC-PUFA) like eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) are known to be potent biological regulators with therapeutic and preventive effects on human health. Many global health organizations have recommended consuming marine based omega-3 sources for neonatal brain development and reducing the risk of various chronic diseases. However, due to concerns regarding the origin, sustainable supply and safety of the marine sources, alternative n-3 PUFA sources are being explored. Recently, plant-based omega-3 sources are gaining much importance because of their sustainable supply and dietary acceptance. α-linolenic acid (ALA, 18:3n-3) rich seed oils are the major omega-3 fatty acid source available for human consumption. But, efficiency of conversion of ALA to n-3 LC-PUFAs in humans is limited due to a rate-limiting step in the n-3 pathway catalyzed by Δ6-desaturase. Botanical stearidonic acid (SDA, 18:4n-3) rich oils are emerging as a sustainable omega-3 source with efficient conversion rate to n-3 LC-PUFA especially to EPA, as it bypasses the Δ6-desaturase rate limiting step. Several recent studies have identified the major plant sources of SDA and explored its potential health benefits and preventive roles in inflammation, cardiovascular disease (CVD) and cancer. This systematic review summarizes the current state of knowledge on the sources, nutraceutical roles, food-based applications and the future perspectives of botanical SDA.

Integrated Therapeutic Targeting of the Prostate Tumor Microenvironment

Prostate cancer is a common and deadly cancer among men. The heterogeneity that characterizes prostate tumors contributes to clinical challenges in the diagnosis, prognosis, and treatment of this malignancy. While localized prostate cancer can be treated with surgery or radiotherapy, metastatic disease to the lymph nodes and the bone requires aggressive treatment with androgen deprivation treatment (ADT). Unfortunately, this often eventually progresses to metastatic castration-resistant prostate cancer (mCRPC). Advanced prostate cancer treatment today involves 1st- and 2nd-line taxane chemotherapy and 2nd-generation antiandrogens. The process of epithelial mesenchymal transition (EMT), during which epithelial cells lose their adhesions and their polarity, is a critical contributor to prostate cancer metastasis. In this article, we aim to integrate the current understanding of mechanisms dictating the dynamics of phenotypic EMT, with apoptosis outcomes in prostate tumors in response to antiandrogen and taxane chemotherapy for the treatment of advanced disease. Novel insights into the signaling mechanisms that target the functional interface between apoptosis and EMT will be considered in the context of potential clinical markers of tumor prognosis, as well as for effective therapeutic targeting of α- and β- adrenergic signaling (by novel and existing chemotherapeutic agents and antiandrogens). Interfering with EMT and apoptosis simultaneously toward eradicating the tumor mass is of major significance in combating the lethal disease and increasing patient survival.

Encapsulation and Controlled Release of Resveratrol Within Functionalized Mesoporous Silica Nanoparticles for Prostate Cancer Therapy

Resveratrol (RES) is a naturally existing polyphenol which exhibits anti-oxidant, anti-inflammatory, and anti-cancer properties. In recent years, RES has attracted attention for its synergistic effect with other anti-cancer drugs for the treatment of drug resistant cancers. However, RES faces the issues of poor pharmacokinetics, stability and low solubility which limits its clinical application. In present study, RES has been loaded onto uniformly sized (~60 nm) mesoporous silica nanoparticles (MSNs) to improve its in vitro anti-proliferative activity and sensitization of Docatexal in hypoxia induced drug resistance in prostate cancer. RES was efficiently encapsulated within phosphonate (negatively charged) and amine (positively charged) modified MSNs. The effect of surface functionalization was studied on the loading, in vitro release, anti-proliferative and cytotoxic potential of RES using prostate cancer cell line. At pH 7.4 both free and NH2-MSNs loaded RES showed burst release which was plateaued with almost 90% of drug released in first 12 h. On the other hand, PO3-MSNs showed significantly slower release kinetics with only 50% drug release in first 12 h at pH 7.4. At pH 5.5, however, both the PO3-MSNs and NH2-MSNs showed significant control over release (around 40% less release compared with free RES in 24 h). Phosphonate modified MSNs significantly enhanced the anti-proliferative potential of RES with an IC50 of 7.15 μM as compared to 14.86 μM of free RES whereas amine modified MSNs didn't affect proliferation with an IC50 value higher than free RES (20.45 μM). Furthermore, RES loaded onto PO3-MSNs showed robust and dose dependent sensitization of Docatexal in hypoxic cell environment which was comparable to pure RES solution. This study provides an example of applicability of MSNs loaded with polyphenols such as RES as next generation anticancer formulations for treating drug resistant cancers such as prostate cancer.

Male-biased zebrafish sex differentiation and metabolomics profile changes caused by dydrogesterone

Some progestins, including the widely used dydrogesterone (DDG), have been shown to cause male-biased sex ratio in teleost. However, there is a gap to fully understand the mechanisms of the sex differentiation disturbance by progestins, particularly from the metabolic aspect. We thus aimed to examine the sex changes by exposing zebrafish embryos to 4.4 (L), 44 (M) and 440 (H) ng/L DDG for up to 140 days, and investigated metabolomic profile changes during the critical period of sex differentiation at fry stage (35 dpf). DDG increased the percentage of male zebrafish in a dose-dependent manner, with 98% male fish in the high concentration group. In zebrafish fry, DDG increased the levels of some free fatty acids, monoglycerides, acylcarnitines, organic acids, free amino acids, while decreased lysophospholipids, uric acid and bile acids. DDG exposure also decreased the nucleoside monophosphates and UDP-sugars while increased nucleosides and their bases. These metabolite changes, namely increase in n-3 PUFAs (polyunsaturated fatty acids), myo-inositol, taurine, palmitoleic acid, oleic acid, lactic acid, fumaric acid, and uracil, and decrease in uric acid and bile acids, might account for the male-biased sex ratio in zebrafish. It appears that many of these metabolites could inhibit several pathways that regulate zebrafish gonad differentiation, including NF-κB/COX-2 and Wnt/β-catenin pathways, and activate p53 pathway. Thus we proposed a hypothesis that DDG might induce oocytes apoptosis through the above pathways and finally lead to female-to-male sex reversal. The results from this study suggest that DDG at environmentally relevant concentrations could affect zebrafish metabolomic profiles and finally disturb fish sex differentiation.