Anti-growth Effects Research Articles

Costunolide Induces Apoptosis via the Reactive Oxygen Species and Protein Kinase B Pathway in Oral Cancer Cells.

Oral cancer (OC) has been attracted research attention in recent years as result of its high morbidity and mortality. Costunolide (CTD) possesses potential anticancer and bioactive abilities that have been confirmed in several types of cancers. However, its effects on oral cancer remain unclear. This study investigated the potential anticancer ability and underlying mechanisms of CTD in OC in vivo and in vitro. Cell viability and anchorage-independent colony formation assays were performed to examine the antigrowth effects of CTD on OC cells; assessments for migration and invasion of OC cells were conducted by transwell; Cell cycle and apoptosis were investigated by flow cytometry and verified by immunoblotting. The results revealed that CTD suppressed the proliferation, migration and invasion of oral cancer cells effectively and induced cell cycle arrest and apoptosis; regarding the mechanism, CTD bound to AKT directly by binding assay and repressed AKT activities through kinase assay, which thereby downregulating the downstream of AKT. Furthermore, CTD remarkably promotes the generation of reactive oxygen species by flow cytometry assay, leading to cell apoptosis. Notably, CTD strongly suppresses cell-derived xenograft OC tumor growth in an in vivo mouse model. In conclusion, our results suggested that costunolide might prevent progression of OC and promise to be a novel AKT inhibitor.

The anti-cancer potential of crotoxin in estrogen receptor-positive breast cancer: Its effects and mechanism of action

Estrogen receptor-positive (ER+) breast cancer is the most diagnosed subtype of breast cancer. Currently, aromatase inhibitors (AIs) are used as first-line treatment option in this type of tumors, however they cause several side effects, which is why new therapeutic approaches are demanding. The South American rattlesnake Crotalus durissus terrificus produces a venom enriched in several bioactive substances, like phospholipases A2 (PLA2). One of those is crotoxin, a β-neurotoxin, that has already been reported for its anti-cancer properties in different cancers. Recently, its clinical interest has emerged and, in fact, a clinical trial in patients with advanced cancer is underway. Considering this, in this work, we studied the biological mechanisms behind the anti-cancer effects of crotoxin B (CTX) in an ER+ aromatase-overexpressing breast cancer cell line (MCF-7aro cells). Results revealed that CTX impairs MCF-7aro cells growth, through a cell cycle arrest at G2/M phase, inhibition of ERK1/2 pathway and by apoptosis through activation of caspase-8. In addition, it can be considered a safe natural compound as did not affect non-cancerous cells and only showed anti-growth effects in breast cancer cells. Therefore, this study represents an important landmark to better understand the effects and mechanisms of action of crotoxin in ER+ breast cancer.

Exploiting D2 receptor β-arrestin2-biased signalling to suppress tumour growth of pituitary adenomas.

Dopamine agonists targeting D2 receptor have been used for decades in treating pituitary adenomas. There has been little clear evidence implicating the canonical G protein signalling as the mechanism by which D2 receptor suppresses the growth of pituitary tumours. We hypothesize that β-arrestin2-dependent signalling is the molecular mechanism dictating D2 receptor inhibitory effects on pituitary tumour growth. The involvement of G protein and β-arrestin2 in bromocriptine-mediated growth suppression in rat MMQ and GH3 tumour cells was assessed. The anti-growth effect of a β-arrestin2-biased agonist, UNC9994, was tested in cultured cells, tumour-bearing nude mice and primary cultured human pituitary adenomas. The effect of G protein signalling on tumour growth was also analysed by using a G protein-biased agonist, MLS1547, and a Gβγ inhibitor, gallein, in vitro. β-arrestin2 signalling but not G protein pathways mediated the suppressive effect of bromocriptine on pituitary tumour growth. UNC9994 inhibited pituitary tumour cell growth in vitro and in vivo. The suppressive function of UNC9994 was obtained by inducing intracellular reactive oxygen species generation through downregulating mitochondrial complex I subunit NDUFA1. The effects of Gαi/o signalling and Gβγ signalling via D2 receptor on pituitary tumour growth were cell-type-dependent. Given the very low expression of Gαi/o proteins in pituitary tumours and the complexity of the responses of pituitary tumours to G protein signalling pathways, our study reveals D2 receptor β-arrestin2-biased ligand may be a more promising choice to treat pituitary tumours with improved therapeutic selectivity.

Rhein Suppresses Colorectal Cancer Cell Growth by Inhibiting the mTOR Pathway In Vitro and In Vivo.

Simple SummaryColorectal cancer (CRC) is the fourth most common cancer and the second most common cause of cancer-related deaths globally. Rhein is a natural anthraquinone extract from rhubarb, which exhibits potent anticancer activity in various cancers. In this study, we show that rhein significantly inhibited the growth, migration, and invasion of CRC cells by directly binding to mTOR and inhibiting the mTOR signaling pathway. Rhein promotes mTOR degradation through the ubiquitin–proteasome pathway. In addition, rhein significantly suppressed tumor growth in a xenograft mouse model without obvious toxicity. Our results indicate that rhein is a promising anticancer agent that may be useful for the prevention and treatment of CRC.Colorectal cancer (CRC) is one of the leading causes of mortality and morbidity in the world. Rhein has demonstrated therapeutic effects in various cancer models. However, its effects and underlying mechanisms of action in CRC remain poorly understood. We investigated the potential anticancer activity and underlying mechanisms of rhein in CRC in vitro and in vivo. Cell viability and anchorage-independent colony formation assays were performed to examine the antigrowth effects of rhein on CRC cells. Wound-healing and Transwell assays were conducted to assess cell migration and invasion capacity. Cell cycle and apoptosis were investigated by flow cytometry and verified by immunoblotting. A tissue microarray was used to detect mTOR expression in CRC patient tissues. Gene overexpression and knockdown were done to analyze the function of mTOR in CRC. The anticancer effect of rhein in vivo was assessed in a CRC xenograft mouse model. The results show that rhein significantly inhibited CRC cell growth by inducing S-phase cell cycle arrest and apoptosis. Rhein inhibited CRC cell migration and invasion through the epithelial–mesenchymal transition (EMT) process. mTOR was highly expressed in CRC cancer tissues and cells. Overexpression of mTOR promoted cell growth, migration, and invasion, whereas mTOR knockdown diminished these phenomena in CRC cells in vitro. In addition, rhein directly targeted mTOR and inhibited the mTOR signaling pathway in CRC cells. Rhein promoted mTOR degradation through the ubiquitin-proteasome pathway. Intraperitoneal administration of rhein inhibited HCT116 xenograft tumor growth through the mTOR pathway. In conclusion, rhein exerts anticancer activity in vitro and in vivo by targeting mTOR and inhibiting the mTOR signaling pathway in CRC. Our results indicate that rhein is a potent anticancer agent that may be useful for the prevention and treatment of CRC.

642 REDD1 (regulated in development and DNA damage 1) is essential for skin wound healing

The major adverse effects of topical glucocorticoids (GCs) are skin atrophy and impaired wound healing, especially pronounced in older patients. Previously we showed that knockout of REDD1, a negative regulator of mTOR/Akt signaling, protects skin from GCs-induced atrophy. Here we investigated whether REDD1 status affected wound healing delay induced by GCs using REDD1 KO and isogenic C57Blx129 12-15-month-old mice. Wound healing in untreated REDD1 KO mice was slightly delayed compared to WT animals. Glucocorticoid fluocinolone acetonide (FA) significantly delayed wound healing in WT and especially in REDD1 KO mice. As expected, FA inhibited keratinocyte proliferation near the wound edge in WT animals. In contrast, in REDD1 KO, FA increased the proliferation by ∼50-70%, resulting in epidermal hyperplasia above the level induced by wounding. The complex process of wound healing involves increased keratinocyte migration and proliferation at the wound edge. Thus, we accessed the effect of REDD1 on proliferation and motility using human HaCaT keratinocytes with CRISPR/Cas9-generated REDD1 KO. In a scratch assay, the wound closed faster in REDD1 KO than in WT/Cas9 cells. However, when proliferation was inhibited by Mitomycin C, WT and REDD1 KO keratinocytes showed similar migration activity. In correlation with in vivo results, REDD1 KO HaCaT cells became resistant to FA anti-growth effects. RNA-seq analysis of the WT and REDD1 KO HaCaT transcriptome revealed significant alteration of FA molecular signature and consistent upregulation of cell cycle regulators CDK1, CCNA2, CCNB1, CCNB2 and proliferation marker PCNA in REDD1 KO keratinocytes. Overall, REDD1 regulated keratinocyte growth but not motility, suggesting that abnormal, non-controlled keratinocyte proliferation during skin wound healing could be an undelaying mechanism of significant wound healing delay induced by GCs in REDD1 KO mice.

Enhanced cell death effects of MAP kinase inhibitors in propyl gallate-treated lung cancer cells are related to increased ROS levels and GSH depletion

Propyl gallate (PG) has an anti-growth effect in lung cancer cells. The present study investigated the effects of mitogen-activated protein kinase (MAPK; MEK, JNK, and p38) inhibitors on PG-treated Calu-6 and A549 lung cancer cells in relation to cell death as well as reactive oxygen species (ROS) and glutathione (GSH) levels. PG induced cell death in both Calu-6 and A549 lung cancer cells at 24 h, which was accompanied by loss of mitochondrial membrane potential (MMP; ΔΨm). All of the tested MAPK inhibitors increased cell death in both PG-treated lung cancer cell lines. In particular, MEK inhibitor strongly enhanced cell death and MMP (ΔΨm) loss in PG-treated Calu-6 cells and p38 inhibitor had the same effects in A549 cells as well. PG increased ROS levels and caused GSH depletion in both cell lines at 24 h. MAPK inhibitors increased O2•- levels and GSH depletion in PG-treated Calu-6 cells, and JNK and p38 inhibitors increased ROS levels and GSH depletion in PG-treated A549 cells. In conclusion, MAPK inhibitors increased cell death in PG-treated Calu-6 and A549 lung cancer cells. Enhanced cell death and GSH depletion in Calu-6 cells caused by the MEK inhibitor were related to increased O2•- levels, and the effects of the p38 inhibitor in A549 cells were correlated with increased general ROS levels.

Evaluation of the Effects of Nanomicellar Curcumin, Berberine, and Their Combination with 5-Fluorouracil on Breast Cancer Cells.

Breast cancer is one of the main challenging areas in cancer treatment. Natural compounds such as curcumin and berberine have been approved with anticancer effects and are more favorable to people. Here, we investigated the potential synergistic anticancer effects of these two compounds in combination with the standard cancer drug 5-FU on the growth of MCF-7 breast cancer cells. This study tested the effects of six different treatments on cancer cell growth: A) control; B) curcumin; C) berberine; D) 5-FU; E) curcumin + berberine; and F) curcumin + berberine + 5-FU. The IC50 concentration of each treatment on cancer cell growth was determined using the MTT assay. Invasiveness of cells grown in 3D culture was analyzed using the transwell chamber technique. Expression levels of genes involved in cancer cell growth and survival (WNT1, APC, AXIN1, CTNNB1, TCF, MTOR, AKT1, MAPK1, PTEN, BIRC5, CCNG1) were evaluated by real-time PCR. There was a reduction in cancer cell growth and invasion, and an increase in cellular decomposition across all treatment groups compared to the control with the strongest effects seen in the combined curcumin/berberine/5-FU group. The expression levels of all tested genes were altered in all treatment groups compared to the control, with that of WNT1, CTNNB1, TCF, MTOR, AKT1, BIRC5, and CCND1 showing the most robust changes in the combined curcumin/berberine/5-FU treatment. All treatment groups had anti-growth, anti-invasion, and pro-apoptotic effects on MCF-7 breast cancer cells in culture. In addition, all treatment groups showed changes in the expression of the genes involved in cancer cell growth and survival with the strongest effects found for the curcumin/berberine/5-FU combination. Therefore, curcumin and berberine may improve the anticancer effects of chemotherapy and these natural compounds should undergo further testing as potential adjuvants.

Anticancer effects of 6-shogaol via the AKT signaling pathway in oral squamous cell carcinoma.

Objective Oral squamous cell carcinoma (OSCC) is one of the common type of cancer that leads to death; and is becoming a global concern. Due to the lack of efficient chemotherapeutic agents for patients with oral cancer, the prognosis remains poor. 6-shogaol, a bioactive compound of ginger, has a broad spectrum of bioactivities and has been widely used to relieve many diseases. However, its effects on human oral cancer have not yet been fully evaluated. In our study, we investigated the anticancer effects of 6-shogaol on the proliferation, migration, invasion, apoptosis, and underlying mechanisms within human OSCC cell lines.Methodology We investigated the effect of 6-shogaol on the growth of OSCC cells by cell viability and soft agar colony formation assay. Migration and invasion assays were conducted to confirm the effect 6-shogaol on OSCC cell metastasis. Apoptosis was detected by flow cytometry and the underlying mechanism on the antigrowth effect of 6-shogaol in OSCC cells was assessed using western blotting.Results In our results, 6-shogaol not only suppressed proliferation and anchorage-independent cell growth in OSCC cells, but also induced apoptosis by regulating the apoptosis-associated factors such as p53, Bax, Bcl-2, and cleaved caspase-3. Migration and invasion of OSCC cells were inhibited following the regulation of E-cadherin and N-cadherin by 6-shogaol. Additionally, 6-shogaol treatment significantly inhibited the PI3K/AKT signaling pathway.Conclusion Therefore, our results may provide critical evidence that 6-shogaol can be a potential new therapeutic candidate for oral cancer.

20(S)-Ginsenoside Rh2 Suppresses Oral Cancer Cell Growth by Inhibiting the Src-Raf-ERK Signaling Pathway.

20(S)-Ginsenoside Rh2 (G-Rh2) has demonstrated therapeutic effects in many types of cancers. We aimed to investigate the potential anticancer activity and underlying mechanisms of G-Rh2 in oral cancer cells. The antigrowth effect of G-Rh2 in oral cancer cells was stimulated by cell proliferation, soft agar colony formation, and migration and invasion assay. The cell cycle and apoptosis were detected by flow cytometry. The underlying mechanism of G-Rh2 in oral cancer cells was explored by immunoblotting. G-Rh2 significantly inhibited oral cancer cell growth by inducing apoptosis and cell cycle G0/G1-phase arrest. G-Rh2 inhibited oral cancer cell migration and invasion through regulation of epithelial-mesenchymal transition (EMT)-related proteins. G-Rh2 inhibited the Src/Raf/ERK signaling pathway in YD10B and Ca9-22 cells. G-Rh2 exerted anticancer activity in vitro by inhibiting the Src/Raf/ERK signaling pathway in oral cancer. G-Rh2 is a potential therapeutic drug for oral cancer treatment.

6]-Gingerol Suppresses Oral Cancer Cell Growth by Inducing the Activation of AMPK and Suppressing the AKT/mTOR Signaling Pathway.

[6]-Gingerol, a compound extracted from ginger, has been studied for its therapeutic potential in various types of cancers. However, its effects on oral cancer remain largely unknown. Here, we aimed to investigate the potential anticancer activity and underlying mechanisms of [6]-gingerol in oral cancer cells. We analyzed the antigrowth effects of [6]-gingerol in oral cancer cell lines by cell proliferation, colony formation, migration, and invasion assays. We detected cell cycle and apoptosis with flow cytometry and further explored the mechanisms of action by immunoblotting. [6]-Gingerol significantly inhibited oral cancer cell growth by inducing apoptosis and cell cycle G2/M phase arrest. [6]-Gingerol also inhibited oral cancer cell migration and invasion by up-regulating E-cadherin and down-regulating N-cadherin and vimentin. Moreover, [6]-gingerol induced the activation of AMPK and suppressed the AKT/mTOR signaling pathway in YD10B and Ca9-22 cells. [6]-Gingerol exerts anticancer activity by activating AMPK and suppressing the AKT/mTOR signaling pathway in oral cancer cells. Our findings highlight the potential of [6]-gingerol as a therapeutic drug for oral cancer treatment.

Soloxolone methyl, as a 18βH-glycyrrhetinic acid derivate, may result in endoplasmic reticulum stress to induce apoptosis in breast cancer cells

Being one of the leading causes of cancer death among women, various chemotherapeutic agents isolated from natural compounds are used in breast cancer treatment and consequently studies to develop new drugs still continue. There are several studies on 18βH-glycyrrhetinic acid, a secondary metabolite which is found in Glycyrrhiza glabra (liquorice roots), as a potential anticancer agent. In this study, the cytotoxic and apoptotic effects of Soloxolone methyl compound, a semisynthetic derivative of 18βH-glycyrrhetinic acid were investigated on breast cancer cells (MCF-7, MDA-MBA-231). Soloxolone methyl is found to be cytotoxic on both MCF-7 and MDA-MBA-231 breast cancer cells by inducing apoptosis. Especially in MDA-MB-231 cells apoptosis is detected to be triggered by ER stress. The antigrowth effects of Soloxolone methyl were determined using MTT and ATP assays. To identify the mode of cell death (apoptosis/necrosis), fluorescent staining (Hoechst 33342 and Propidium iodide) and caspase-cleaved cytokeratin 18 (M30-antigen) analyses were used. In addition, apoptosis was investigated on gene and protein levels by PCR and Western Blotting. Soloxolone methyl decreased cell viability on cells in a dose and time-dependent manner and induced apoptosis markers. An increase on apoptotic proteins related to endoplasmic reticulum stress (IRE1-α, Bip, CHOP) was also determined in MDA-MB-231 cells. Moreover, an increase of apoptotic gene expressions was determined in both cells treated with Soloxolone methyl. Advance analyses should be performed to elucidate the potential of Soloxolone methyl as an anticancer agent in breast cancer treatment.

Magnolol Suppresses Pancreatic Cancer Development In Vivo and In Vitro via Negatively Regulating TGF-β/Smad Signaling.

Magnolol, a hydroxylated biphenyl extracted from Magnolia officinalis, has recently drawn attention due to its anticancer potential. The present study was aimed to explore the effects of Magnolol on restraining the proliferation, migration and invasion of pancreatic cancer in vivo and in vitro. Magnolol showed significant anti-growth effect in an orthotopic xenograft nude mouse model, and immunohistochemical staining of the xenografts revealed that Magnolol suppressed vimentin expression and facilitated E-cadherin expression. The cytoactive detection using CCK-8 assay showed Magnolol inhibited PANC-1 and AsPC-1 concentration-dependently. Scratch healing assay and the Transwell invasion assay proved the inhibiting effects of Magnolol on cellular migration and invasion at a non-cytotoxic concentration. Western blot and rt-PCR showed that Magnolol suppressed epithelial-mesenchymal-transition by increasing the expression level of E-cadherin and decreasing those of N-cadherin and vimentin. Magnolol suppressed the TGF-β/Smad pathway by negatively regulating phosphorylation of Smad2/3. Moreover, TGF-β1 impaired the antitumor effects of Magnolol in vivo. These results demonstrated that Magnolol can inhibit proliferation, migration and invasion in vivo and in vitro by suppressing the TGF-β signal pathway and EMT. Magnolol could be a hopeful therapeutic drug for pancreatic malignancy.

Perspectives on the current pharmacotherapeutic strategies for management of functional neuroendocrine tumor syndromes

ABSTRACT Introduction: In the past, controlling the hormone-excess-state was the main determinant of survival in Functional-Neuroendocrine-Neoplasm-syndromes (F-NENs). This was difficult because the pharmacological-armamentarium available was limited. Recently, new therapeutic strategies have increased but it also generated controversies/uncertainties. Areas covered: The authors briefly review: established/proposed F-NENs; the rationale for treatments; the recommended initial-pharmacotherapeutic-approach to controlling F-NENs hormone-excess-state; the secondary-approaches if the initial approach fails or resistance develops; and the approach to deal with the malignant nature of the NEN. Also discussed are controversies/uncertainties related to new treatments. Expert opinion: Unfortunately, except for patients with insulinomas (>90-95%), gastrinomas (<20-40%), a minority with the other F-panNENs and 0-<1% with Carcinoid-syndrome is curative-surgery possible. Except for insulinomas, gastrinomas, and ACTHomas, long-acting somatostatin-analogs are the initial-pharmacological-treatments for hormone-excess-state. For insulinomas prior to surgery/malignancy, diazoxide is the initial drug-treatment; for gastrinomas, oral PPIs; and for ACTHomas, steroidogenesis inhibitors. There are now several secondary pharmacotherapeutic treatments. Surgery and liver-directed therapies also have a role in selected patients. Particularly promising is the recent results with PRRT for the hormone-excess-state, independent of its anti-growth effect. The sequence to use various agents and the approach to syndrome diagnosis while taking various agents remains unclear/controversial in many cases.

Does currency misalignment matter for economic growth? – Evidence from Turkey

PurposeThe study mainly aims to examine the currency misalignment of Turkish lira and evaluate if it has an impact on economic growth of Turkey.Design/methodology/approachIt relies on Johansen cointegration technique for measuring currency misalignment relying on single-equation approach and the autoregressive distributed lag (ARDL) approach to evaluate how misalignment affects economic growth. The sample period covers from 1980 to 2016.FindingsThe study identifies that terms of trade, relative productivity differences, net foreign asset, investment and trade openness determine the equilibrium REER of Turkey, and the degree of currency misalignment is observed at a substantial level. The outcome of the ARDL approach suggests that higher currency misalignment reduces economic growth. Turning to the separate impacts of undervaluation and overvaluation, while the former falters economic growth, the later promotes it, a finding contrary to the conventional expectation. Therefore, the use of exchange rate as a policy variable is a critical concern to avoid misalignment for sustained economic growth.Practical implicationsThe anti-growth effect of undervaluation and misalignment is an indication of redistribution of income which could be verified by examining the aggregate consumption behavior of the economy in response to RER movements.Originality/valueThe impacts of currency undervaluation and overvaluation on economic growth of Turkey have been studied in a number of time-series studies. But there is no documented study on the role of currency misalignment on Turkish economic growth. This study is the first that examines how the economic growth of Turkey is influenced by currency misalignment together with the impact of undervaluation and overvaluation.

Anti-Survival and Pro-Apoptotic Effects of 6-Shogaol on SW872 Human Liposarcoma Cells via Control of the Intrinsic Caspase Pathway, STAT-3, AMPK, and ER Stress.

Notably, 6-Shogaol, a bioactive natural substance, has anticancer effects on many types of tumors. Up to date, the anticancer effect and mode of action of 6-Shogaol on liposarcoma are not known. In this study, we investigated whether 6-Shogaol inhibits the growth of SW872 and 93T449 cells, two different human liposarcoma cell lines. Of note, 6-Shogaol inhibited the growth of SW872 and 93T449 cells without affecting that of normal 3T3-L1 preadipocytes. Specifically, 6-Shogaol further induced the apoptosis of SW872 cells, as evidenced by nuclear DNA fragmentation, increased sub G1 population, activation of the intrinsic caspase pathway, and PARP cleavage. However, pretreatment with either z-VAD-fmk, a pan-caspase inhibitor, or N-acetylcysteine, an antioxidant, attenuated the 6-Shogaol’s growth-suppressive and apoptosis-inducing effects on SW872 cells. Moreover, 6-Shogaol activated AMPK while inhibited STAT-3 in SW872 cells, and siRNA-based genetic silencing of AMPK or STAT-3 considerably blocked the growth-suppressive and apoptotic response of 6-Shogaol to SW872 cells. Moreover, 6-Shogaol also upregulated the expression and phosphorylation of GRP-78, eIF-2α, ATF4, and CHOP, known ER stress markers, in SW872 cells, illustrating the induction of ER stress. These findings collectively demonstrate that 6-Shogaol has strong antigrowth and proapoptotic effects on SW872 cells through regulation of the intrinsic caspase pathway, oxidative stress, STAT-3, AMPK, and ER stress.

Antioxidant functions of DHHC3 suppress anti-cancer drug activities.

Ablation of protein acyltransferase DHHC3 selectively enhanced the anti-cancer cell activities of several chemotherapeutic agents, but not kinase inhibitors. To understand why this occurs, we used comparative mass spectrometry-based palmitoyl-proteomic analysis of breast and prostate cancer cell lines, ± DHHC3 ablation, to obtain the first comprehensive lists of candidate protein substrates palmitoylated by DHHC3. Putative substrates included 22-28 antioxidant/redox-regulatory proteins, thus predicting that DHHC3 should have antioxidant functions. Consistent with this, DHHC3 ablation elevated oxidative stress. Furthermore, DHHC3 ablation, together with chemotherapeutic drug treatment, (a) elevated oxidative stress, with a greater than additive effect, and (b) enhanced the anti-growth effects of the chemotherapeutic agents. These results suggest that DHHC3 ablation enhances chemotherapeutic drug potency by disabling the antioxidant protections that contribute to drug resistance. Affirming this concept, DHHC3 ablation synergized with another anti-cancer drug, PARP inhibitor PJ-34, to decrease cell proliferation and increase oxidative stress. Hence, DHHC3 targeting can be a useful strategy for selectively enhancing potency of oxidative stress-inducing anti-cancer drugs. Also, comprehensive identification of DHHC3 substrates provides insight into other DHHC3 functions, relevant to in vivo tumor growth modulation.

Abstract A42: Potassium channel activity unveils ovarian cancer vulnerability: From signaling to precision medicine

Abstract Decades of studies on ion channels have vastly demonstrated the critical functions of these proteins in many physiologic and pathologic conditions. Also, studies on ion channels have provided for an extraordinary pharmacopeia of useful compounds, often with selective actions and minimal side effects. Nevertheless, the function of ion channels in controlling cancer biology is still unknown and underexplored. Our research demonstrates that the Kir6.2/SUR2 potassium ion channel can be a prognostic factor in gynecologic cancers. Here we present data showing that the Kir6.2/SUR2 channel activity control biochemical pathways underlying proliferation and metabolism in gynecologic cancers, including endometrioid and high-grade serous ovarian cancer. Use of activators of the Kir6.2/SUR2 produced an arrest of the cell cycle, a significant mitochondrial dysfunction that is associated with alteration of the oxidative cellular state and DNA damage in cisplatin-resistant ovarian cancer. Also, our in vivo experiments show the antigrowth effects of pharmacologically targeting Kir6.2/SUR2 on ovarian cancer with FDA-approved molecules. This study offers the opportunity to consider the therapeutic benefits of repurposing drugs targeting the Kir6.2/SUR2 channel for a treatment of gynecologic cancers that is efficient and safe. Citation Format: Daniela Fukushiro Lopes, Alexandra Hegel, Vitaly Senyuk, Angela Russo, Margaret Liotta, Ronald Potkul, Craig Beeson, Joanna Brurgette, Saverio Gentile. Potassium channel activity unveils ovarian cancer vulnerability: From signaling to precision medicine [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research; 2019 Sep 13-16, 2019; Atlanta, GA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(13_Suppl):Abstract nr A42.

Newly Synthesized Palladium (II) Complex ASH10 Induces Apoptosis and Autophagy in Breast Cancer Cells

Background and Objective: Palladacycles have been reported to exert significant anticancer activities against different cancer cells. The current study conducted to evaluate the anti-tumor activity of a new palladacycle complex (ASH10) in estrogen receptor-positive (MCF7) and triple-negative (HCC1937) breast cancer cells. Materials and Methods: The effect of ASH10 on cell proliferation was tested by MTT assay. Scratch assay was used to test the anti-migration ability of ASH10. Apoptosis induced by ASH10 was measured by different methods including nuclear staining and detection of apoptosis markers by western blotting. Autophagy induced by ASH10 also measured by LC3II puncta staining and western blotting using the LC3II antibody. Results: The MTT results showed that the ASH10 compound has a strong anti-growth effect. Data showed that ASH10 induces its cytotoxic effect by inducing DNA damage followed by cell cycle arrest, intrinsic apoptosis and autophagy. Compared to untreated cells, ASH10 treated cells showed high levels of DNA damage markers p-H2AX, p-ATM and p53. Importantly, the cell cycle arrest marker p21 was similarly induced by ASH10 treatment. Furthermore, ASH10 induced significant levels of apoptosis as evidenced by nuclear fragmentation and an increase in the levels of PARP cleavage. Interestingly, ASH10 also activated the formation of autophagosomes and increased the autophagy marker LC3II. Inhibition of autophagy led to a decrease in ASH10 cytotoxicity suggesting that ASH10 induced autophagy was a cytotoxic mechanism. Conclusion: These results demonstrated that ASH10 is a potential effective compound in the treatment of both ER-negative and ER-positive breast cancer cells.

Pidotimod enhanced the anti-growth effect of cisplatin on lung cancer in mice via promoting anti-tumor immune response

Cisplatin-based chemotherapeutics represent a mainstay of lung cancer therapy, but resistance limits their curative potential. In the current study, we reported that Pidotimod, which is an immunostimulant and used for the prevention of acute respiratory infections, elevated cisplatin sensitivity, leading to the synergistic attenuation of tumor growth in mouse lewis lung cancer (LLC) model. With further exploration, we found that Pidotimod enhanced the anti-growth effect of cisplatin on LLC via promoting anti-tumor response, such as increased infiltration of dendrite cells (DCs) and CD8+ T cells as well as enhancement of IFN-γ and Granzyme B expression. In summary, Pidotimod affects the anti-tumor function of cisplatin via promoting anti-tumor immune response and these findings provide a novel approach for the development of therapeutic strategies for lung cancer.

Differential effects and mechanisms of local anesthetics on esophageal carcinoma cell migration, growth, survival and chemosensitivity

BackgroundRetrospective analysis and pre-clinical studies suggest that local anesthetics have anti-tumoral effects. However, the association between cancer recurrence and the use of local anesthesia is inconclusive and most reports are based on single local anesthetic results.MethodsThe biological effects (growth, migration and survival) of four common local anesthetics on esophageal carcinoma cells were compared. Biochemical assays on molecules involved in cell migration and proliferation were analyzed.ResultsRopivacaine and bupivacaine significantly inhibited esophageal carcinoma cell migration, at clinically relevant micromolar concentrations. Mepivacaine and lidocaine showed less potent cell migration inhibition than ropivacaine or bupivacaine. All four local anesthetics inhibited cell proliferation. Of note, the effective concentration of anti-proliferative activities requires higher doses. At millimolar concentrations of these local anesthetics, cell apoptosis was moderately affected. Drug combination analysis demonstrated that two of four local anesthetics augmented chemotherapeutic drugs in inhibiting migration. However, all four local anesthetics significantly augmented chemotherapeutic drugs in inhibiting growth and inducing apoptosis. The anti-growth and anti-survival effects of four local anesthetics were attributed to mitochondrial dysfunction and oxidative damage. The anti-migratory effect of local anesthetics is likely through decreasing Rac1 activity.ConclusionsOur work demonstrates the differential effects and proposes the mechanisms of local anesthetics on esophageal carcinoma cell migration, growth, survival and chemosensitivity.