Linoleic acid exhibits anti-proliferative and anti-invasive activities in endometrial cancer cells and a transgenic model of endometrial cancer.

Emerging evidence has provided considerable insights into the integral function of reprogramming fatty acid metabolism in the carcinogenesis and progression of endometrial cancer. Linoleic acid, an essential fatty acid with the highest consumption in the Western diet regimen, has shown pro-tumorigenic or anti-tumorigenic effects on tumor cell growth and invasion in multiple types of cancer. However, the biological role of linoleic acid in endometrial cancer remains unclear. In the present study, we aimed to investigate the functional impact of linoleic acid on cell proliferation, invasion, and tumor growth in endometrial cancer cells and in a transgenic mouse model of endometrial cancer. The results showed that Linoleic acid significantly inhibited the proliferation of endometrial cancer cells in a dose-dependent manner. The treatment of HEC-1A and KLE cells with linoleic acid effectively increased intracellular reactive oxygen species (ROS) production, decreased mitochondrial membrane potential, caused cell cycle G1 arrest, and induced intrinsic and extrinsic apoptosis pathways. The anti-invasive ability of linoleic acid was found to be associated with the epithelial-mesenchymal transition process in both cell lines, including the decreased expression of N-cadherin, snail, and vimentin. Furthermore, treatment of Lkb1fl/flp53fl/fl transgenic mice with linoleic acid for four weeks significantly reduced the growth of endometrial tumors and decreased the expression of VEGF, vimentin, Ki67, and cyclin D1 in tumor tissues. Our findings demonstrate that linoleic acid exhibits anti-proliferative and anti-invasive activities in endometrial cancer cell lines and the Lkb1fl/flp53fl/fl mouse model of endometrial cancer, thus providing a pre-clinical basis for future dietary interventions with linoleic acid in endometrial cancer.

High-dose ascorbate exerts anti-tumor activities and improves inhibitory effect of carboplatin through the pro-oxidant function pathway in uterine serous carcinoma cell lines.

OBJECTIVE: Uterine serous carcinoma is a highly aggressive non-endometrioid subtype of endometrial cancer with poor survival rates overall, creating a strong need for new therapeutic strategies to improve outcomes. High-dose ascorbate (vitamin C) has been shown to inhibit cell proliferation and tumor growth in multiple preclinical models and has shown promising anti-tumor activity in combination with chemotherapy, with a favorable safety profile. We aimed to study the anti-tumor effects of ascorbate and its synergistic effect with carboplatin on uterine serous carcinoma cells. METHODS: Cell proliferation was evaluated by MTT and colony formation assays in ARK1, ARK2 and SPEC2 cells. Cellular stress, antioxidant ability, cleaved caspase 3 activity and adhesion were measured by ELISA assays. Cell cycle was detected by Cellometer. Invasion was measured using a wound healing assay. Changes in protein expression were determined by Western immunoblotting. RESULTS: High-dose ascorbate significantly inhibited cell proliferation, caused cell cycle arrest, induced cellular stress, and apoptosis, increased DNA damage, and suppressed cell invasion in ARK1 and SPEC2 cells. Treatment of both cells with 1 mM N-acetylcysteine reversed ascorbate-induced apoptosis and inhibition of cell proliferation. The combination of ascorbate and carboplatin produced significant synergistic effects in inhibiting cell proliferation and invasion, inducing cellular stress, causing DNA damage, and enhancing cleaved caspase 3 levels compared to each compound alone in both cells. CONCLUSIONS: Ascorbate has potent antitumor activity and acts synergistically with carboplatin through its pro-oxidant effects. Clinical trials of ascorbate combined with carboplatin as adjuvant treatment of uterine serous carcinoma are worth exploring.

Intermittent energy restriction inhibits tumor growth and enhances paclitaxel response in a transgenic mouse model of endometrial cancer.

Objective: Overweight/obesity is the strongest risk factor for endometrial cancer (EC), and weight management can reduce that risk and improve survival. We aimed to establish the differential abilities of intermittent energy restriction (IER) and low-fat diet (LFD), alone and in combination with paclitaxel, to reverse the procancer effects of high-fat diet (HFD)-induced obesity in a mouse model of EC. Methods: Lkb1 fl/fl p53 fl/fl mice were fed high-fat diet (HFD) or LFD to generate obese and lean phenotypes, respectively. Obese mice were maintained on HFD or switched to LFD (HFD-LFD) or IER (HFD-IER). Ten weeks after induction of endometrial tumor, mice in each group received paclitaxel or placebo for 4 weeks. Body and tumor weights; tumoral transcriptomic, metabolomic and oxylipin profiles; and serum metabolic hormones and chemocytokines were assessed. Results: HFD-IER and HFD-LFD, relative to HFD, reduced body weight; reversed obesity-induced alterations in serum insulin, leptin and inflammatory factors; and decreased tumor incidence and mass, often to levels emulating those associated with continuous LFD. Concurrent paclitaxel, versus placebo, enhanced tumor suppression in each group, with greatest benefit in HFD-IER. The diets produced distinct tumoral gene expression and metabolic profiles, with HFD-IER associated with a more favorable (antitumor) metabolic and inflammatory environment. Conclusion: In Lkb1 fl/fl p53 fl/fl mice, IER is generally more effective than LFD in promoting weight loss, inhibiting obesity-related endometrial tumor growth (particularly in combination with paclitaxel), and reversing detrimental obesity-related metabolic effects. These findings lay the foundation for further investigations of IER as a EC prevention strategy in women with overweight/obesity.

Oleic Acid Exhibits Anti-Proliferative and Anti-Invasive Activities via the PTEN/AKT/mTOR Pathway in Endometrial Cancer.

Reprogramming of fatty acid metabolism promotes cell growth and metastasis through a variety of processes that stimulate signaling molecules, energy storage, and membrane biosynthesis in endometrial cancer. Oleic acid is one of the most important monounsaturated fatty acids in the human body, which appears to have both pro- and anti-tumorigenic activities in various pre-clinical models. In this study, we evaluated the potential anti-tumor effects of oleic acid in endometrial cancer cells and the LKB1fl/flp53fl/fl mouse model of endometrial cancer. Oleic acid increased lipogenesis, inhibited cell proliferation, caused cell cycle G1 arrest, induced cellular stress and apoptosis, and suppressed invasion in endometrial cancer cells. Targeting of diacylglycerol acyltransferases 1 and 2 effectively increased the cytotoxicity of oleic acid. Moreover, oleic acid significantly increased the expression of wild-type PTEN, and knockdown of PTEN by shRNA partially reversed the anti-proliferative and anti-invasive effects of oleic acid. Inhibition of the AKT/mTOR pathway by ipatasertib effectively increased the anti-tumor activity of oleic acid in endometrial cancer cells. Oleic acid treatment (10 mg/kg, daily, oral) for four weeks significantly inhibited tumor growth by 52.1% in the LKB1fl/flp53fl/fl mice. Our findings demonstrated that oleic acid exhibited anti-tumorigenic activities, dependent on the PTEN/AKT/mTOR signaling pathway, in endometrial cancer.

Orlistat exerts anti-obesity and anti-tumorigenic effects in a transgenic mouse model of endometrial cancer.

Introduction: Among all cancers, endometrial cancer is most strongly associated with obesity, with more than 65% of endometrial cancers attributable to obesity and being overweight. Fatty acid synthase (FAS), a key lipogenic enzyme, is expressed in endometrial cancer tumors and is associated with a worse prognosis for this disease. Orlistat, an FAS inhibitor, is an FDA-approved weight loss medication that has demonstrated anti-tumor activity in a variety of preclinical cancer models. Methods: In this study, the Lkb1fl/flp53fl/fl mouse model of endometroid endometrial cancer was exposed to three diet interventions, including a high fat diet (obese), a low fat diet (lean) and switch from a high fat to a low fat diet, and then exposed to orlistat or placebo. Results: The mice fed a high-fat diet had significantly increased body weight and tumor weight compared to mice fed a low-fat diet. Switching from a high-fat diet to a low fat diet led to a reduction in mouse weight and suppressed tumor growth, as compared to both the high fat diet and low fat diet groups. Orlistat effectively decreased body weight in obese mice and inhibited tumor growth in obese, lean, and the high fat diet switch to low fat diet mouse groups through induction of apoptosis. Orlistat also showed anti-proliferative activity in nine of 11 primary cultures of human endometrial cancer. Discussion: Our findings provide strong evidence that dietary intervention and orlistat have anti-tumor activity in vivo and supports further investigation of orlistat in combination with dietary interventions for the prevention and treatment of endometrial cancer.

Inhibition of CDK1 by RO-3306 Exhibits Anti-Tumorigenic Effects in Ovarian Cancer Cells and a Transgenic Mouse Model of Ovarian Cancer.

Ovarian cancer is the deadliest gynecological malignancy of the reproductive organs in the United States. Cyclin-dependent kinase 1 (CDK1) is an important cell cycle regulatory protein that specifically controls the G2/M phase transition of the cell cycle. RO-3306 is a selective, ATP-competitive, and cell-permeable CDK1 inhibitor that shows potent anti-tumor activity in multiple pre-clinical models. In this study, we investigated the effect of CDK1 expression on the prognosis of patients with ovarian cancer and the anti-tumorigenic effect of RO-3306 in both ovarian cancer cell lines and a genetically engineered mouse model of high-grade serous ovarian cancer (KpB model). In 147 patients with epithelial ovarian cancer, the overexpression of CDK1 was significantly associated with poor prognosis compared with a low expression group. RO-3306 significantly inhibited cellular proliferation, induced apoptosis, caused cellular stress, and reduced cell migration. The treatment of KpB mice with RO-3306 for four weeks showed a significant decrease in tumor weight under obese and lean conditions without obvious side effects. Overall, our results demonstrate that the inhibition of CDK1 activity by RO-3306 effectively reduces cell proliferation and tumor growth, providing biological evidence for future clinical trials of CDK1 inhibitors in ovarian cancer.

Ipatasertib exhibits anti­tumorigenic effects and enhances sensitivity to paclitaxel in endometrial cancer in vitro and in vivo.

Endometrial cancer is the most common gynecologic cancer and one of the only cancers for which incidence and mortality is steadily increasing. Although curable with surgery in the early stages, endometrial cancer presents a significant clinical challenge in the metastatic and recurrent setting with few novel treatment strategies emerging in the past fifty years. Ipatasertib (IPAT) is an orally bioavailable pan­AKT inhibitor, which targets all three AKT isoforms and has demonstrated anti­tumor activity in pre­clinical models, with clinical trials emerging for many cancer types. In the present study, the MTT assay was employed to evaluate the therapeutic efficacy of IPAT or IPAT in combination with paclitaxel (PTX) in endometrial cancer cell lines and primary cultures of endometrial cancer. The effect of IPAT and PTX on the growth of endometrial tumors was evaluated in a transgenic mouse model of endometrial cancer. Apoptosis was assessed using cleaved caspase assays and cellular stress was assessed using ROS, JC1 and tetramethylrhodamine ethyl ester assays. The protein expression levels of markers of apoptosis and cellular stress, and DNA damage were evaluated using western blotting and immunohistochemistry. IPAT significantly inhibited cell proliferation, caused cell cycle G1 phase arrest, and induced cellular stress and mitochondrial apoptosis in a dose dependent manner in human endometrial cancer cell lines. Combined treatment with low doses of IPAT and PTX led to synergistic inhibition of cell proliferation and induction of cleaved caspase 3 activity in the human endometrial cancer cell lines and the primary cultures. Furthermore, IPAT effectively reduced tumor growth, accompanied by decreased protein expression levels of Ki67 and phosphorylation of S6 in the Lkb1fl/flp53fl/fl mouse model of endometrioid endometrial cancer. The combination of IPAT and PTX resulted in increased expression of phosphorylated­H2AX and KIF14, markers of DNA damage and microtubule dysfunction respectively, as compared with IPAT alone, PTX alone or placebo­treated mice. The results of the present study provide a biological rationale to evaluate IPAT and the combination of IPAT and PTX in future clinical trials for endometrial cancer.

A novel dopamine receptor D2 antagonist (ONC206) potentiates the effects of olaparib in endometrial cancer.

Poly ADP-ribose polymerase (PARP) inhibitors are effective therapies for cancer patients with homologous recombination (HR) deficient tumors. The imipridone ONC206 is an orally bioavailable dopamine receptor D2 antagonist and mitochondrial protease ClpP agonist that has anti-tumorigenic effects in endometrial cancer via induction of apoptosis, activation of the integrated stress response and modulation of PI3K/AKT signaling. Both PARP inhibitors and imipridones are being evaluated in endometrial cancer clinical trials but have yet to be explored in combination. In this manuscript, we evaluated the effects of the PARP inhibitor olaparib in combination with ONC206 in human endometrioid endometrial cancer cell lines and in a genetically engineered mouse model of endometrial cancer. Our results showed that simultaneous exposure of endometrial cancer cells to olaparib and ONC206 resulted in synergistic anti-proliferative effects and increased cellular stress and apoptosis in both cell lines, compared to either drug alone. The combination treatment also decreased expression of the anti-apoptotic protein Bcl-2 and reduced phosphorylation of AKT and S6, with greater effects compared to either drug alone. In the transgenic model of endometrial cancer, the combination of olaparib and ONC206 resulted in a more significant reduction in tumor weight in obese and lean mice compared to ONC206 alone or olaparib alone, together with a considerably decreased Ki-67 and enhanced H2AX expression in obese and lean mice. These results suggest that this novel dual therapy may be worthy of further exploration in clinical trials.

Ipatasertib, an oral AKT inhibitor, in combination with carboplatin exhibits anti-proliferative effects in uterine serous carcinoma.

PURPOSE: Uterine serous carcinoma (USC) exhibits worse survival rates compared to the endometrioid subtype, and there is currently no effective treatment options for recurrence of this disease after platinum-based chemotherapy. Activation of PIK3CA/AKT/mTOR signaling pathway is a common biological feature in USC. MATERIALS AND METHODS: Ipatasertib (IPAT) is an investigational, orally administered, ATP-competitive, highly selective inhibitor of pan AKT that has demonstrated anti-proliferative activity in a variety of tumor cells and tumor models. In this study, we used IPAT, carboplatin and their combination to investigate the anti-tumor activity in SPEC-2 and ARK-1 cells. RESULTS: Our results indicate that IPAT combined with carboplatin at low doses was more effective at reducing proliferation, inducing apoptosis and causing cellular stress than IPAT or carboplatin alone. In particular, inhibition of the PIK3CA/AKT/mTOR pathway and induction of DNA damage were involved in the synergistic inhibition by combination treatment of cell viability in USC cells treated with the combination. Furthermore, IPAT in combination with carboplatin significantly reduced cell adhesion and inhibited cell invasion. CONCLUSIONS: These findings suggest that the combination of IPAT and carboplatin has potential clinical implications for developing new USC treatment strategies.

Asparagus officinalis combined with paclitaxel exhibited synergistic anti-tumor activity in paclitaxel-sensitive and -resistant ovarian cancer cells.

PURPOSE: Although paclitaxel is a promising first-line chemotherapeutic drug for ovarian cancer, acquired resistance to paclitaxel is one of the leading causes of treatment failure, limiting its clinical application. Asparagus officinalis has been shown to have anti-tumorigenic effects on cell growth, apoptosis, cellular stress and invasion of various types of cancer cells and has also been shown to synergize with paclitaxel to inhibit cell proliferation in ovarian cancer. METHODS: Human ovarian cancer cell lines MES and its PTX-resistant counterpart MES-TP cell lines were used and were treated with Asparagus officinalis and paclitaxel alone as well as in combination. Cell proliferation, cellular stress, invasion and DMA damage were investigated and the synergistic effect of a combined therapy analyzed. RESULTS: In this study, we found that Asparagus officinalis combined with low-dose paclitaxel synergistically inhibited cell proliferation, induced cellular stress and apoptosis and reduced cell invasion in paclitaxel-sensitive and -resistant ovarian cancer cell lines. The combined treatment effects were dependent on DNA damage pathways and suppressing microtubule dynamics, and the AKT/mTOR pathway and microtubule-associated proteins regulated the inhibitory effect through different mechanisms in paclitaxel-sensitive and -resistant cells. CONCLUSION: These findings suggest that the combination of Asparagus officinalis and paclitaxel have potential clinical implications for development as a novel ovarian cancer treatment strategy.

Ipatasertib, an oral AKT inhibitor, inhibits cell proliferation and migration, and induces apoptosis in serous endometrial cancer.

Ipatasertib (IPAT) is an orally administered, selective protein kinase B (AKT) inhibitor with promising data in solid tumors in both pre-clinical studies and clinical trials. Given that the PI3K/AKT/mTOR pathway is frequently dysregulated in uterine serous carcinoma (USC), we aimed to explore the functional impact of IPAT on anti-tumorigenic activity in USC cell lines and primary cultures of USC. We found that IPAT significantly inhibited cell proliferation and colony formation in a dose-dependent manner in USC cells. Induction of cell cycle arrest and apoptosis was observed in IPAT-treated ARK1 and SPEC-2 cells. Treatment with IPAT resulted in reduced adhesion and invasion of both cell lines with a concomitant decrease in the expression of Snail, Slug, and N-Cadherin. Compared with single-drug treatment, the combination of IPAT and paclitaxel synergistically reduced cell proliferation and increased the activity of cleaved caspase 3 in both cell lines. Additionally, IPAT inhibited growth in four of five primary USC cultures, and three of five primary cultures also exhibited synergistic growth inhibition when paclitaxel and IPAT were combined. These results support that IPAT appears to be a promising targeted agent in the treatment of USC.

Anti-Tumor and Anti-Invasive Effects of ONC201 on Ovarian Cancer Cells and a Transgenic Mouse Model of Serous Ovarian Cancer.

ONC201 is a promising first-in-class small molecule that has been reported to have anti-neoplastic activity in various types of cancer through activation of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) as well as activation of mitochondrial caseinolytic protease P (ClpP). The present study was to explore the anti-tumor potential effect of ONC201 in ovarian cancer cell lines and in a transgenic mouse model of high grade serous ovarian cancer under obese (high fat diet) and lean (low fat diet) conditions. ONC201 significantly suppressed cell proliferation, induced arrest in G1 phase, and increased cellular stress and apoptosis, accompanied by dual inhibition of the AKT/mTOR/S6 and MAPK pathways in OC cells. ONC201 also resulted in inhibition of adhesion and invasion via epithelial-mesenchymal transition and reduction of VEGF expression. Pre-treatment with the anti-oxidant, N-acetylcysteine (NAC), reversed the ONC201-induced oxidative stress response, and prevented ONC201-reduced VEGF and cell invasion by regulating epithelial-mesenchymal transition protein expression. Knockdown of ClpP in ovarian cancer cells reduced ONC201 mediated the anti-tumor activity and cellular stress. Diet-induced obesity accelerated ovarian tumor growth in the KpB mouse model. ONC201 significantly suppressed tumor growth, and decreased serum VEGF production in obese and lean mice, leading to a decrease in tumoral expression of Ki-67, VEGF and phosphorylation of p42/44 and S6 and an increase in ClpP and DRD5, as assessed by immunohistochemistry. These results suggest that ONC201 may be a promising therapeutic agent to be explored in future clinical trials in high-grade serous ovarian cancer.

ONC206 has anti-tumorigenic effects in human ovarian cancer cells and in a transgenic mouse model of high-grade serous ovarian cancer.

ONC206, a dopamine receptor D2 (DRD2) antagonist and imipridone, is a chemically modified derivative of ONC201. Recently, ONC206 and other imipridones were identified as activators of the mitochondrial protease ClpP, inducing downstream pathways that allow them to selectively target cancer cells. Clinical trials showed that ONC201, the first in class imipridone, was well tolerated and exhibited tumor regression in some solid tumors. Our goal was to evaluate the effect of ONC206 on cell proliferation and tumor growth in ovarian cancer cell lines and in a transgenic mouse model of high grade serous ovarian cancer (KpB model). ONC206 was more potent than ONC201 in inhibiting cell proliferation, as evidenced by a 10-fold decrease in IC50 for the SKOV3 and OVCAR5 cell lines. This was accompanied by the results that ONC206 significantly inhibited cellular proliferation, induced cell cycle G1 arrest and apoptosis, caused cellular stress, and inhibited adhesion and invasion in vitro. Treatment of obese and non-obese KpB mice with ONC206 elevated Bip and ClpP expression and reduced KI67, BCL-XL and DRD2 expression in the ovarian tumors. Our findings demonstrate that ONC206 has anti-tumorigenic effects in ovarian cancer as previously demonstrated by ONC201 but appears to be as well tolerated and more potent. Thus, ONC206 deserves further evaluation in clinical trials.

Highly potent dopamine receptor D2 antagonist ONC206 demonstrates anti-tumorigenic activity in endometrial cancer.

Endometrial cancer (EC) is a highly obesity-driven cancer, with limited treatment options. ONC201 is an imipridone that selectively antagonizes the G protein-coupled receptors dopamine receptor D2 and D3 (DRD2/3) and activates human mitochondrial caseinolytic protease P (ClpP). It is a promising first-in-class small molecule that has been reported to have anti-neoplastic activity in various types of cancer through induction of the integrated stress response (ISR) as well as through stimulation of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and subsequent induction of apoptosis. ONC201 is being evaluated in Phase II clinical trials for solid tumors and hematological malignancies, including EC. ONC206 is an analog of ONC201 with nanomolar potency in Phase I clinical trials. This study evaluated the anti-tumor efficacy of ONC206 in EC cell lines and the Lkb1fl/flp53fl/fl genetically engineered mouse model of endometrioid EC. ONC206 revealed greater potency than ONC201 in the inhibition of proliferation in EC cell lines, with IC50 concentration ranges of 0.21-0.32 µM for ONC026 versus 2.14-3.53 µM for ONC201. ONC206 induced cellular stress, apoptosis and cell cycle G1 arrest, accompanied by inhibition of the AKT/mTOR/S6 pathways in EC cells. Diet-induced obesity accelerated tumor growth in Lkb1fl/flp53fl/fl mice. ONC206 inhibited EC tumor size and weight in both obese and lean mice after 4 weeks of treatment. Treatment with ONC206 led to a decrease in expression of Ki67, BCL-XL and phosphorylation of S6, as well as an increase in ClpP in endometrial tumors under both obese and lean conditions. Overall, the pre-clinical efficacy of ONC206 is promising and worthy of further exploration in clinical trials for endometrioid EC.

The Effects of NT-1044, a Novel AMPK Activator, on Endometrial Cancer Cell Proliferation, Apoptosis, Cell Stress and In Vivo Tumor Growth.

OBJECTIVES: Anti-diabetic biguanide drugs such as metformin may have anti-tumorigenic effects by behaving as AMPK activators and mTOR inhibitors. Metformin requires organic cation transporters (OCTs) for entry into cells, and NT-1044 is an AMPK activator designed to have greater affinity for two of these transporters, OCT1 and OCT3. We sought to compare the effects of NT-1044 on cell proliferation in human endometrial cancer (EC) cell lines and on tumor growth in an endometrioid EC mouse model. METHODS: Cell proliferation was assessed in two EC cell lines, ECC-1 and Ishikawa, by MTT assay after exposure to NT-1044 for 72 hours of treatment. Apoptosis was analyzed by Annexin V-FITC and cleaved caspase 3 assays. Cell cycle progression was evaluated by Cellometer. Reactive oxygen species (ROS) were measured using DCFH-DA and JC-1 assays. For the in vivo studies, we utilized the LKB1fl/flp53fl/fl mouse model of endometrioid endometrial cancer. The mice were treated with placebo or NT-1044 or metformin following tumor onset for 4 weeks. RESULTS: NT-1044 and metformin significantly inhibited cell proliferation in a dose-dependent manner in both EC cell lines after 72 hours of exposure (IC50 218 µM for Ishikawa; 87 µM for ECC-1 cells). Treatment with NT-1044 resulted in G1 cell cycle arrest, induced apoptosis and increased ROS production in both cell lines. NT-1044 increased phosphorylation of AMPK and decreased phosphorylation of S6, a key downstream target of the mTOR pathway. Expression of the cell cycle proteins CDK4, CDK6 and cyclin D1 decreased in a dose-dependent fashion while cellular stress protein expression was induced in both cell lines. As compared to placebo, NT-1044 and metformin inhibited endometrial tumor growth in obese and lean LKB1fl/flp53fl/fl mice. CONCLUSIONS: NT-1044 suppressed EC cell growth through G1 cell cycle arrest, induction of apoptosis and cellular stress, activation of AMPK and inhibition of the mTOR pathway. In addition, NT-1044 inhibited EC tumor growth in vivo under obese and lean conditions. More work is needed to determine if this novel biguanide will be beneficial in the treatment of women with EC, a disease strongly impacted by obesity and diabetes.

Asparagus officinalis Exhibits Anti-Tumorigenic and Anti-Metastatic Effects in Ovarian Cancer.

Ovarian cancer is one of the leading causes of female cancer death. Emerging evidence suggests that many dietary natural products have anti-tumorigenic activity, including that of asparagus officinalis. The current study aimed to assess the anti-tumorigenic and anti-metastatic effects of asparagus officinalis on serous ovarian cancer cell lines and a transgenic mouse model of high grade serous ovarian cancer. Asparagus officinalis decreased cellular viability, caused cell cycle G1 phase arrest and induced apoptosis in the OVCAR5 and SKOV3 cells. Induction of apoptosis and inhibition of cell proliferation was rescued by the pan-caspase inhibitor, Z-VAD-FMK, implying that its cytotoxic effects were mainly dependent on caspase pathways. Asparagus officinalis increased levels of ROS and decreased mitochondrial membrane potential with corresponding increases in PERK, Bip, Calnexin PDI and ATF4 in both cell lines. Treatment with asparagus officinalis also reduced ability of adhesion and invasion through epithelial-mesenchymal transition and reduction of VEGF expression. The combination of Asparagus officinalis with paclitaxel had synergistic anti-proliferative activity. Furthermore, Asparagus officinalis significantly inhibited tumor growth and reduced serum VEGF in a genetically engineered mouse model of ovarian cancer under obese and lean conditions, accompanied with a decrease in the expression of Ki67, VEGF and phosphorylated S6, and in an increase in phosphorylation of AMPK in the ovarian tumor tissues. Overall, our data provide a pre-clinical rationale for asparagus officinalis in the prevention and treatment of ovarian cancer as a novel natural product.

Targeting dopamine receptor D2 as a novel therapeutic strategy in endometrial cancer.

BACKGROUND: ONC201 is a dopamine receptor D2 (DRD2) antagonist that inhibits tumor growth in preclinical models through ClpP activation to induce integrated stress response pathway and mitochondrial events related to inhibition of cell growth, which is being explored in clinical trials for solid tumors and hematological malignancies. In this study, we investigated the anti-tumorigenic effect of ONC201 in endometrial cancer cell lines and a genetically engineered mouse model of endometrial cancer. METHODS: Cell proliferation was assessed by MTT and colony formation assays. Cell cycle and apoptosis were evaluated by Cellometer. Invasion capacity was tested using adhesion, transwell and wound healing assays. LKB1fl/flp53fl/fl mouse model of endometrial cancer were fed a control low fat diet versus a high fat diet to mimic diet-induced obesity. Following tumor onset, mice were treated with placebo or ONC201. Metabolomics and lipidomics were used to identify the obesity-dependent effects of ONC201 in the mouse endometrial tumors. DRD2 expression was analyzed by immunohistochemistry in human endometrioid and serous carcinoma specimens. DRD2 mRNA expression from the Cancer Genome Atlas (TCGA) database was compared between the four molecular subtypes of endometrial cancer. RESULTS: Increasing DRD2 expression in endometrial cancer was significantly associated with grade, serous histology and stage, as well as worse progression free survival and overall survival. Higher expression of DRD2 mRNA was found for the Copy Number High (CNH) subtype when compared to the other subtypes. ONC201 inhibited cell proliferation, induced cell cycle G1 arrest, caused cellular stress and apoptosis and reduced invasion in endometrial cancer cells. Diet-induced obesity promoted endometrial tumor growth while ONC201 exhibited anti-tumorigenic efficacy in the obese and lean LKB1fl/fl/p53fl/fl mice. Metabolomic analysis demonstrated that ONC201 reversed the obesity-driven upregulation of lipid biosynthesis and reduced protein biosynthesis in obese and lean mice. CONCLUSION: ONC201 has anti-tumorigenic effects in endometrial cancer cells and a transgenic mouse model of endometrial cancer, and DRD2 expression was documented in both human serous and endometrioid endometrial cancer. These studies support DRD2 antagonism via ONC201 as a promising therapeutic strategy for endometrial cancer that has already demonstrated pharmacodynamic activity and clinical benefit in both serous and endometrioid endometrial cancer patients.

ONC206, an Imipridone Derivative, Induces Cell Death Through Activation of the Integrated Stress Response in Serous Endometrial Cancer In Vitro.

ONC206 (Oncoceutics) is an imipiridone with nanomolar potency and analogue of ONC201, a selective dopamine receptor D2 (DRD2) antagonist currently being investigated in phase II clinical trials for serous endometrial cancer (SEC). This study investigated the anti-proliferative efficacy of ONC206 in SEC cell lines as well as its impact on cellular stress and adhesion/invasion. ONC206 inhibited cellular proliferation in a dose-dependent manner and was more potent than ONC201 in the ARK1 (IC50 = 0.33µM vs. IC50 = 1.59uM) and SPEC-2 (IC50 = 0.24uM vs. IC50 = 0.81uM) cell lines. Treatment with ONC206 resulted in induction of ROS production and reduction of mitochondrial membrane potential, accompanied by an increase in cleaved caspase-3 and caspase-9 activity (p < 0.01). ONC206 also significantly inhibited cellular adhesion and migration in both cell lines (p < 0.01). Pretreatment with the stress inhibitor N-acetylcysteine (NAC) significantly attenuated the efficacy of ONC206 on cell proliferation, ROS production and cellular invasion. ONC206 demonstrates nanomolar potency for the inhibition of proliferation in SEC cells. Specifically, ONC206 utilizes ISR activation as a significant pathway in the propagation of its anti-proliferative and anti-metastatic effects. Thus, ONC206 may be a promising agent in future SEC clinical trials as was its predecessor ONC201.

SPR064, a pro-drug of paclitaxel, has anti-tumorigenic effects in endometrial cancer cell lines and mouse models.

Paclitaxel is one of the most effective and widely used agents in treating a variety of cancers, including endometrial cancer. Because of its poor solubility in water, the current intravenous pharmaceutical paclitaxel is formulated in Cremophor EL and dehydrated in ethanol in equal volumes. Cremophor EL is capable of causing complement activation, which can trigger an immediate hypersensitivity reaction. SPR064 is a pro-drug of paclitaxel which has a much higher solubility as compared to the parent drug; hence, SPR064 can be conveniently formulated in non-cremapor based medium, reducing the risk of cremaphor-related hypersensitivity reactions. The pharmacokinetics and solubility of SPR064 were evaluated in rats. The anti-tumorigenic potential of SPR064 was compared to paclitaxel in endometrial cancer cell lines and a genetically engineered mouse model (Lkbfl/flp53fl/fl ) of endometrial cancer. Overall, SPR064 exhibited improved solubility and better exposure to drug in rats when compared to paclitaxel. SPR064 and paclitaxel inhibited cell proliferation, induced apoptosis, enhanced cellular stress and caused cell cycle G1 arrest in endometrial cancer cell lines, with similar potency. Both SPR064 and paclitaxel reduced tumor weight in the Lkbfl/flp53fl/fl mouse model under obese and lean conditions compared to their respective controls. Immunohistochemical staining demonstrated that SPR064 and paclitaxel significantly reduced the expression of Ki-67 and BCL-xL in the endometrial tumors of both obese and lean mice. In summary, SPR064 has anti-tumorigenic effects that are equivalent to paclitaxel in endometrial cancer cell lines and a genetically engineered mouse model of endometrial cancer. Thus, SPR064 may be a promising therapy for endometrial cancer without the significant risk of hypersensitivity reactions seen with paclitaxel.

SPR965, a Dual PI3K/mTOR Inhibitor, as a Targeted Therapy in Ovarian Cancer.

SPR965 is an inhibitor of PI3K and mTOR C1/C2 and has demonstrated anti-tumorigenic activity in a variety of solid tumors. We sought to determine the effects of SPR965 on cell proliferation and tumor growth in human serous ovarian cancer cell lines and a transgenic mouse model of high grade serous ovarian cancer (KpB model) and identify the underlying mechanisms by which SPR965 inhibits cell and tumor growth. SPR965 showed marked anti-proliferative activity by causing cell cycle arrest and inducing cellular stress in ovarian cancer cells. Treatment with SPR965 significantly inhibited tumor growth in KpB mice, accompanied by downregulation of Ki67 and VEGF and upregulation of Bip expression in ovarian tumors. SPR965 also inhibited adhesion and invasion through induction of the epithelial-mesenchymal transition process. As expected, downregulation of phosphorylation of AKT and S6 was observed in SPR965-treated ovarian cancer cells and tumors. Our results suggest that SPR965 has significant anti-tumorigenic effects in serous ovarian cancer in vitro and in vivo. Thus, SPR965 should be evaluated as a promising targeted agent in future clinical trials of ovarian cancer.