Human Ovarian Carcinoma Cells Research Articles

Ru(II)-Arene Complexes of Curcumin and Bisdesmethoxycurcumin Metabolites.

Curcuminoids and their complexes continue to attract attention in medicinal chemistry, but little attention has been given to their metabolic derivatives. Here, the first examples of (arene)Ru(II) complexes with curcuminoid metabolites, tetrahydrocurcumin (THcurcH), and tetrahydrobisdesmethoxycurcumin (THbdcurcH) were prepared and characterized. The neutral complexes [Ru(arene)(THcurc)Cl] and [Ru(arene)(THbdcurc)Cl] (arene = cymene, benzene, or hexamethylbenzene) were characterized by NMR spectroscopy and ESI mass spectrometry, and the crystal structures of the three complexes were determined by X-ray diffraction analysis. Compared to curcuminoids, these metabolites lose their conjugated double bond system responsible for their planarity, showing unique closed conformation structures. Both closed and open conformations have been analyzed and rationalized by using density functional theory (DFT). The cytotoxicity of the complexes was evaluated in vitro against human ovarian carcinoma cells (A2780 and A2780cisR), human breast adenocarcinoma cells (MCF-7 and MCF-7CR), as well as against non-tumorigenic human embryonic kidney cells (HEK293) and human breast (MCF-10A) cells and compared to the free ligands, cisplatin, and RAPTA-C. There is a correlation between cellular uptake and the cytotoxicity of the compounds, suggesting that cellular uptake and binding to nuclear DNA may be the major pathway for cytotoxicity. However, the levels of complex binding to DNA do not strictly correlate with the cytotoxic potency, indicating that other mechanisms are also involved. In addition, treatment of MCF-7 cells with [Ru(cym)(THcurc)Cl] showed a significant decrease in p62 protein levels, which is generally assumed as a noncisplatin-like mechanism of action involving autophagy. Hence, a cisplatin- and a noncisplatin-like concerted mechanism of action, involving both apoptosis and autophagy, is possible.

Establishment of a human ovarian clear cell carcinoma cell line mutant in PIK3CB but not PIK3CA.

A human ovarian clear cell carcinoma cell line was established from a 46-year-old Japanese woman. That line, designated MTC-22, has proliferated continuously for over 6months in conventional RPMI 1640 medium supplemented with 10% foetal bovine serum and has been passaged over 50 times. MTC-22 doubling-time is ~ 18h, which is much shorter than most ovarian clear cell carcinoma lines reported to date. Morphologically, MTC-22 cells exhibit polygonal shapes and proliferate to form a monolayer in a jigsaw puzzle-like arrangement without contact inhibition. Ultrastructurally, cells exhibit numerous intracytoplasmic glycogen granules and well-developed mitochondria. G-band karyotype analysis indicated that cells have a complex karyotype close to tetraploid. We observed that the expression pattern of a series of ovarian carcinoma-related molecules in MTC-22 cells was identical to that seen in the patient's tumour tissue. Notably, MTC-22 cells, and the patient's carcinoma tissue, expressed low-sulphated keratan sulphate recognised by R-10G and 294-1B1 monoclonal antibodies, a hallmark of non-mucinous ovarian carcinoma, and particularly of clear cell ovarian carcinoma. Moreover, characteristic point mutations-one in ARID1A, which encodes the AT-rich interaction domain containing protein 1A, and the other in PIK3CB, which encodes the catalytic subunit of phosphoinositide 3-kinase-were seen in the patient's tumour tissue and retained in MTC-22 cells. Collectively, these findings indicate that MTC-22 cells could serve as a valuable tool for investigating the pathophysiology of ovarian clear cell carcinoma, particularly that harbouring PIK3CB mutations, and for developing and validating new diagnostic and therapeutic approaches to this life-threatening malignancy.

Structural Elucidation and Prognostic Relevance of 297-11A-Sulfated Glycans in Ovarian Carcinoma

Ovarian carcinoma is usually diagnosed at an advanced stage with peritoneal dissemination and/or lymph node metastasis, and the prognosis for such advanced carcinoma is very poor. Therefore, new biomarkers to predict patient prognosis are needed. Miyamoto et al. previously showed that keratan sulfate (KS) detected by the 5D4 monoclonal antibody was expressed in ovarian carcinoma. However, the detailed structure of such KS was not determined, and the biological significance of this finding remained to be clarified. We previously generated the 297-11A monoclonal antibody, which recognizes galactose (Gal)-6-O-sulfated N-acetyllactosamine (LacNAc) located at the nonreducing terminus. Because the 297-11A epitope overlaps with that of 5D4, here we chose to use the 297-11A antibody as a tool to analyze KS and related structures. We conducted immunohistochemical analysis of 98 ovarian carcinoma cases with 297-11A antibody combined with a series of glycosidases and performed mass spectrometry analysis of the human serous ovarian carcinoma cell line OVCAR-3 to deduce the glycan structure of 297-11A-sulfated glycans. We also performed western blot analysis to assess a potential association of 297-11A-sulfated glycans with the mucin core protein mucin 16 (MUC16; also known as cancer antigen 125 (CA125)). Finally, we examined the relationship between 297-11A expression and patient prognosis. Consequently, 297-11A-sulfated glycans were primarily expressed in serous and endometrioid carcinomas and poorly expressed in mucinous and clear cell carcinomas. We reveal that structurally, 297-11A-sulfated glycans expressed in ovarian carcinoma are O-glycans carrying partially sialylated, Gal-6-O-sulfated LacNAc and that these glycans are likely displayed on MUC16 mucin core proteins. Of clinical importance is that expression of 297-11A-sulfated glycans correlated with shorter progression-free survival in patients. Thus, 297-11A-sulfated glycans may serve as a predictor of ovarian carcinoma recurrence.

Bio-inspired deposition of gold nanoparticles onto the surface of kaolin for in vitro management of human ovarian cancer and modulation of the inflammatory response in adenomyosis-induced mice in vivo via the MAPK signaling pathway

A mild and eco-friendly protocol has been developed for the preparation of kaolin-decorated Au nanoparticles mediated by Ephedra root extract as a green reducing and stabilizing agents without any toxic substrates. Structural features of the prepared Au NPs/Kaolin were assessed through FE-SEM, TEM, and XRD techniques. TEM images show the good deposition of Au NPs over the surface of extract-modified kaolin without aggregation. Towards the medicinal application, its antioxidant efficacy was assessed by the DPPH method, and the corresponding IC50 value was obtained as 104 μg/mL. Cytotoxicity of the nanoformulated bio-composite was ascertained through MTT analysis against human ovarian carcinoma cells, i.e., PA-1 and SK-OV-3. The IC50 in those studies was 250 and 119 μg/mL against PA-1and SK-OV-3 cells, respectively. In the in vivo design, tamoxifen was used to induce the experimental adenomyosis model in mice. After treatment, the thymus, spleen, uterine, and body weights of all animals were measured. Then, inflammatory factor expression and myometrial infiltration were determined by qRT-PCR, ELISA, and histology examination in the uterus. Western blotting, qRT-PCR, and immune histochemical (IHC) staining were applied to analyze the MAPK/ERK signaling pathway protein expression. Au NPs/Kaolin bio-nanocomposite ameliorated the adenomyosis symptoms by raising the thymus and spleen index and decreasing the myometrial infiltration. The raised levels of TNF-α, IL-6, and IL-1β in adenomyosis model mice uterus and serum were also reduced after Au NPs/Kaolin bio-nanocomposite treatment. The adenomyosis amelioration of Au NPs/Kaolin bio-nanocomposite was gained by preventing the MAPK/ERK signaling pathway, including decreasing the expressions of protein and mRNA of p-p38/p38, p-JNK/JNK, and p-ERK/ERK.

Abstract 524: Using acquired resistance to explore the mechanism of action of the integrated stress response/GCN2 activator NXP800 - A new developmental agent for platinum-resistant ARID1A mutant ovarian cancer

Abstract Background: NXP800 is a potent, oral activator of the Integrated Stress response (ISR), inhibitor of heat shock factor 1 (HSF1) activation and tumor cell proliferation, which is in early clinical studies in ARID1A-mutated, platinum resistant, clear cell ovarian cancer (NCT05226507). We discovered NXP800 using multiparameter medicinal chemistry optimization of a hit identified from a cell-based phenotypic screen. Owing to the unbiased nature of phenotypic screening, target identification is crucial to understand the biological and therapeutic activity of hit compounds. Methods and Results:: By RNAseq profiling human cancer cells treated with NXP800 we identified changes in expression of genes regulated by HSF1 or ATF4 - effects accompanied by eIF2alpha (eIF2a) phosphorylation and resulting activation of the ISR. To further understand this response, we explored whether NXP800 resistance models could inform on its mechanism of action (MoA). We used ARID1A mutant SK-OV-3 human ovarian carcinoma cells that are 1) highly sensitive to NXP800, 2) model the target patient population and 3) MSI-high so likely to have an elevated mutation rate contributing to acquisition of resistance. We generated two independent NXP800-resistant SK-OV-3 cell lines in which NXP800-mediated ATF4 induction and concomitant inhibition of global translation were abolished. By whole exome sequencing, we identified a heterozygous L99P mutation in the alpha subunit of eIF2B (eIF2Ba), the nucleotide exchange factor for eIF2a. Expression of eIF2BaL99P, but not wild-type, in parental SK-OV-3 cells reduced sensitivity to NXP800 to the same level as cells with NXP800-induced resistance. Using fluorescence recovery after photobleaching to monitor the dynamic association of the eIF2B:eIF2a complex, we elucidated that the eIF2BaL99P mutation reduces NXP800-mediated inhibition of eIF2a-GFP recycling through eIF2B bodies. Phosphorylation of eIF2a is regulated by four stress-controlled kinases GCN2, HRI, PKR and PERK. Using systematic siRNA knockdown or small-molecule inhibitors, we showed that GCN2 alone is required for ISR activation by NXP800 and that ISR induction inhibited HSF1 activation. Furthermore, inactivation of GCN2 reduced the antiproliferative activity of NXP800 to the same extent observed in NXP800-resistant SK-OV-3 cells. In contrast, exposure of resistant or parental SK-OV-3 cells expressing eIF2BaL99P to GCN2 inhibitors did not cause further reduction in NXP800 sensitivity - confirming the importance of the eIF2BaL99P mutation in the resistance mechanism. Conclusions: We have used acquired resistance to understand the MoA of NXP800 as a potent activator of GCN2 and the ISR pathway. Further studies are underway to determine the exact proximal molecular target of NXP800 and the mechanism of GCN2/ISR activation. Citation Format: Marissa V. Powers, Rachel Hodgson, Swee Y. Sharp, Toby Roe, K. Elizabeth Allen, Susan Campbell, Robert te Poele, Matthew Cheeseman, Keith Jones, Paul A. Clarke, Paul Workman. Using acquired resistance to explore the mechanism of action of the integrated stress response/GCN2 activator NXP800 - A new developmental agent for platinum-resistant ARID1A mutant ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 524.

Lycorine and homolycorine derivatives for chemo-sensitizing resistant human ovarian adenocarcinoma cells

BackgroundMultidrug resistance is the major obstacle to cancer chemotherapy. Modulation of P-glycoprotein and drug combination approaches have been considered important strategies to overcome drug resistance. PurposeAiming at generating a small library of Amaryllidaceae-type alkaloids to overcome drug resistance, two major alkaloids, isolated from Pancratium maritimum, lycorine (1), and 2α-10bα-dihydroxy-9-O-demethylhomolycorine (2), were derivatized, giving rise to nineteen derivatives (3 – 21). MethodsThe main chemical transformation of lycorine resulted from the cleavage of ring E of the diacetylated lycorine derivative (3) to obtain compounds that have carbamate and amine functions (5 - 16), while acylation of compound 2 provided derivatives 17 – 21. Compounds 1 - 21 were evaluated for their effects on cytotoxicity, and drug resistance reversal, using resistant human ovarian carcinoma cells (HOC/ADR), overexpressing P-glycoprotein (P-gp/ABCB1), as model. ResultsExcluding lycorine (1) (IC50 values of 1.2- 2.5 µM), the compounds were not cytotoxic or showed moderate/weak cytotoxicity. Chemo-sensitization assays were performed by studying the in vitro interaction between the compounds and the anticancer drug doxorubicin. Most of the compounds have shown synergistic interactions with doxorubicin. Compounds 5, 6, 9 – 14, bearing both carbamate and aromatic amine moieties, were found to have the highest sensitization rate, reducing the dose of doxorubicin 5–35 times, highlighting their potential to reverse drug resistance in combination chemotherapy. Selected compounds (4 – 6, 9 – 14, and 21), able of re-sensitizing resistant cancer cells, were further evaluated as P-gp inhibitors. Compound 11, which has a para‑methoxy-N-methylbenzylamine moiety, was the strongest inhibitor. In the ATPase assay, compounds 9–11 and 13 behaved as verapamil, suggesting competitive inhibition of P-gp. At the same time, none of these compounds affected P-gp expression at the mRNA or protein level. ConclusionsThis study provided evidence of the potential of Amaryllidaceae alkaloids as lead candidates for the development of MDR reversal agents.

A PILOT IN VITRO STUDY ON THE EFFECT OF BLUE HONEYSUCKLE EXTRACT ON HUMAN NON-CANCEROUS AND CANCEROUS OVARIAN CELLS

Honeysuckle (Lonicera caerulea L.) is utilized in Chinese, Japanese, and Russian folk medicines for centuries. The berries referred to as blue honeysuckle are recently gaining popularity in central and southern Europe due to remarkable therapeutic potential and widespread use as an ingredient in dietary supplements. The primary objective of this investigation was to examine the impact of blue honeysuckle extract on human ovarian cells – both non-cancerous HGL5 (immortalized human ovarian granulosa cell line) and cancerous OVCAR-3 (human ovarian carcinoma cell line). Cell viability, secretion of steroid hormones (17ß-estradiol and progesterone), human transforming growth factor-β2 (TGFβ-2) and its receptor (TGFBR2), and the level of apoptosis-inducing factor (AIF) were examined in ovarian granulosa cells HGL5, and the same parameters (excepting the steroid hormones) were assessed in ovarian epithelial cancer cells OVCAR-3. Blue honeysuckle ethanolic extract was applied to cells for 24 hours. AlamarBlueTM assay was used to assess cell viability, whereas secretion of steroid hormones was evaluated by ELISA. ELISA was also used to assess the levels of TGF-β2, its receptor TGFBR2 and AIF in HGL5 and OVCAR-3 cell lysates. Based on a range of doses ranging from 5 – 100 μg/mL, the extract from blue honeysuckle had no adverse effects on the viability of human ovarian cells. Futuremore, it did not affect their secretory activity – be it the release of steroid hormones or that of growth factor TGF-β2 and its receptor TGFBR2, nor did induce apoptosis (as revealed by the AIF). The present pilot study for the first time reports the effect of blue honeysuckle extract on ovarian cell models using both non-cancerous cells HGL5 and cancerous OVCAR-3 cells. These findings provide initial insights into the safety and potential utility of blue honeysuckle extract, warranting further investigation into its therapeutic applications. In further research, it is possible to examine a longer exposure time to see if it affects the cells.

Investigation of the cytotoxicity induced by cannabinoids on human ovarian carcinoma cells

AbstractCannabinoids have been shown to induce anti‐tumor activity in a variety of carcinoma cells such as breast, prostate, and brain. The aim of the present study is to investigate the anti‐tumor activity of cannabinoids, CBD (cannbidiol), and CBG (cannabigerol) in ovarian carcinoma cells sensitive and resistant to chemotherapeutic drugs. Sensitive A2780 cells and resistant A2780/CP70 carcinoma cells and non‐carcinoma cells were exposed to varying concentrations of CBD, CBG, carboplatin or CB1 and CB2 receptor antagonists, AM251 and AM630, respectively, alone or in combination, at different exposure times and cytotoxicity was measured by MTT assay. The mechanism of action of CBD and CB in inducing cytotoxicity was investigated involving a variety of apoptotic and cell cycle assays. Treatment with CBD and CBG selectively, dose and time dependently reduced cell viability and induced apoptosis. The effect of CBD was stronger than CBG in all cell lines tested. Both CBD and CBG induced stronger cytotoxicity than afforded by carboplatin in resistant cells. The cytotoxicity induced by CBD was not CB1 or CB2 receptor dependent in both carcinoma cells, however, CBG‐induced cytotoxicity may involve CB1 receptor activity in cisplatin‐resistant carcinoma cells. A synergistic effect was observed when cannabinoids at sublethal doses were combined with carboplatin in both carcinoma cells. The apoptotic event may involve loss of mitochondrial membrane potential, Annexin V, caspase 3/7, ROS activities, and cell cycle arrest. Further studies are required to investigate whether these results are translatable in the clinic. Combination therapies with conventional cancer treatments using cannabinoids are suggested.

Abstract IA014: From targeted phenotypic screen to NXP800: A clinical stage activator of the integrated stress response for the treatment of ARID1A-mutated ovarian carcinoma

Abstract IA014: From targeted phenotypic screen to NXP800: A clinical stage activator of the integrated stress response for the treatment of ARID1A-mutated ovarian carcinoma

Rhamnetin, a nutraceutical flavonoid arrests cell cycle progression of human ovarian cancer (SKOV3) cells by inhibiting the histone deacetylase 2 protein

Overexpression of HDAC 2 promotes cell proliferation in ovarian cancer. HDAC 2 is involved in chromatin remodeling, transcriptional repression, and the formation of condensed chromatin structures. Targeting HDAC 2 presents a promising therapeutic approach for correcting cancer-associated epigenetic abnormalities. Consequently, HDAC 2 inhibitors have evolved as an attractive class of anti-cancer agents. This work intended to investigate the anti-cancer abilities and underlying molecular mechanisms of Rhamnetin in human epithelial ovarian carcinoma cells (SKOV3), which remain largely unexplored. We employed various in vitro methods, including MTT, apoptosis study, cell cycle analysis, fluorescence microscopy imaging, and in vitro enzymatic HDAC 2 protein inhibition, to examine the chemotherapeutic sensitivity of Rhamnetin in SKOV3 cells. Additionally, we conducted in silico studies using molecular docking, MD simulation, MM-GBSA, DFT, and pharmacokinetic analysis to investigate the binding interaction mechanism within Rhamnetin and HDAC 2, alongside the compound’s prospective as a lead candidate. The in vitro assay confirmed the cytotoxic effects of Rhamnetin on SKOV3 cells, through its inhibition of HDAC 2 activity. Rhamnetin, a nutraceutical flavonoid, halted at the G1 phase of the cell cycle and triggered apoptosis in SKOV3 cells. Furthermore, computational studies provided additional evidence of its stable binding to the HDAC 2 protein’s binding site cavity. Based on our findings, we conclude that Rhamnetin effectively promotes apoptosis and mitigates the proliferation of SKOV3 cells through HDAC 2 inhibition. These results highlight Rhamnetin as a potential lead compound, opening a new therapeutic strategy for human epithelial ovarian cancer. Communicated by Ramaswamy H. Sarma

DNA Double-Strand Break Repair Inhibitors: YU238259, A12B4C3 and DDRI-18 Overcome the Cisplatin Resistance in Human Ovarian Cancer Cells, but Not under Hypoxia Conditions.

Cisplatin (CDDP) is the cornerstone of standard treatment for ovarian cancer. However, the resistance of ovarian cancer cells to CDDP leads to an inevitable recurrence. One of the strategies to overcome resistance to CDDP is the combined treatment of ovarian cancer with CDDP and etoposide (VP-16), although this strategy is not always effective. This article presents a new approach to sensitize CDDP-resistant human ovarian carcinoma cells to combined treatment with CDDP and VP-16. To replicate the tumor conditions of cancers, we performed analysis under hypoxia conditions. Since CDDP and VP-16 induce DNA double-strand breaks (DSB), we introduce DSB repair inhibitors to the treatment scheme. We used novel HRR and NHEJ inhibitors: YU238259 inhibits the HRR pathway, and DDRI-18 and A12B4C3 act as NHEJ inhibitors. All inhibitors enhanced the therapeutic effect of the CDDP/VP-16 treatment scheme and allowed a decrease in the effective dose of CDDP/VP16. Inhibition of HRR or NHEJ decreased survival and increased DNA damage level, increased the amount of γ-H2AX foci, and caused an increase in apoptotic fraction after treatment with CDDP/VP16. Furthermore, delayed repair of DSBs was detected in HRR- or NHEJ-inhibited cells. This favorable outcome was altered under hypoxia, during which alternation at the transcriptome level of the transcriptome in cells cultured under hypoxia compared to aerobic conditions. These changes suggest that it is likely that other than classical DSB repair systems are activated in cancer cells during hypoxia. Our study suggests that the introduction of DSB inhibitors may improve the effectiveness of commonly used ovarian cancer treatment, and HRR, as well as NHEJ, is an attractive therapeutic target for overcoming the resistance to CDDP resistance of ovarian cancer cells. However, a hypoxia-mediated decrease in response to our scheme of treatment was observed.

Knockdown of LIMD2 inhibits the progression of ovarian carcinoma through ERK1/2 pathway.

The incidence rate of ovarian carcinoma (OC) is the third of the female reproductive system malignant tumors, while its mortality rate ranks first among causes of female reproductive system tumor related death in the world. In the present research, we investigated the specific role of LIMD2 through LIMD2 knockdown in OC cells. The results of online analysis and expression detection proved that LIMD2 was up-regulated in human OC tissues and cells. Knockdown of LIMD2 inhibited the proliferation, migration and invasion in OC cells. LIMD2 knockdown promoted the apoptosis, as well as the expression of Cleaved-Caspase3 and Bax. Importantly, knockdown of LIMD2 promotes cell autophagy. LC3-II/I ratio and Beclin1 expression increased in LIMD2 knockdown cells, while P62 expression declined in LIMD2 knockdown cells. Additionally, the phosphorylation of ERK1/2 was inhibited by the knockdown of LIMD2 in SKOV3 and OVCAR3 cells. Knockdown of LIMD2 inhibits cell proliferation, migration, invasion and autophagy, and promotes the apoptosis through the ERK1/2 signaling pathway, suggesting that LIMD2-siRNA may be an effective molecule to prevent OC progression.

Novel ternary Pd(II) complexes as potent anticancer drugs for ovarian carcinoma treatment

A novel straightforward method has been introduced to synthesize two new water soluble Pd complexes, [Pd(phd)(AA)]NO3, (phd = 1,10-phenanthroline-5,6-dione; 1, AA = L-isoleucine and 2, AA = L-leucine) using water as a green solvent. Complexes 1 and 2 have been characterized by elemental analysis, FT-IR, 1H NMR spectroscopy and mass spectrometry. A theoretical study of these complexes was conducted using ADME, DFT, and molecular docking. ADME data revealed these complexes as potentially anti-cancer drugs. Fluorescence, UV–Vis, and CD spectroscopy were applied to study the mechanism of DNA interaction. As a result of the fluorescence data, both complexes statically quenched DNA. Based on thermodynamic parameters, Pd(II) complexes and DNA interact via an electrostatic approach and groove binding. CD spectra indicated that both complexes exhibit a slight blue shift with a decrease in intensity across all bands. The experimental data were in agreement with DFT calculations and docking studies. In sum, the mode of binding with DNA intracellular structure is via groove binding and electrostatic interactions. Cytotoxic screening of these compounds carried out against the human ovarian carcinoma cell line A2780SP and cisplatin-resistant variant A2780CP revealed that both complexes showed significantly higher anticancer activity against A2780CP cancer cell line compared to cisplatin. Moreover, all theoretical and experimental data show that complex 2 is more active than complex 1.

The investigation of the effects of calcitriol on human ovarian carcinoma cells

Objective: Ovarian cancer is the fifth leading cause of cancer death in women, the leading cause of death from gynecologic malignancies, and the second most commonly diagnosed gynecologic malignancy, however the underlying pathophysiology is not clearly understood. Calcitriol, the active form of vitamin D serves its activity through binding to vitamin D receptor (VDR). Calcitriol regulates multiple signaling pathways such as proliferation, apoptosis, differentiation, inflammation, invasion, angiogenesis and metastasis. It has been found to have a broad effect on several cancer types such as colon, breast and prostate cancer. Therefore, the aim of the study was to investigate the effects of calcitriol on the human ovarian cancer cells.
 Material and methods: The human MDAH-2774 ovarian carcinoma cells were exposed to different dose ranges of calcitriol for 24 and 48 hours. Cultured cells were evaluated in terms of MTT assay and quantitative- Real time-PCR.
 Results: As evidenced by MTT assay, calcitriol treatment resulted in the reduction of cell viability in human MDAH-2774 cells. The gene expressions of VDR and p53 were increased with the calcitriol treatment compared to control. Additionally the gene expression of proapoptotic marker Bax was increased and the anti-apoptotic marker Bcl-2 decreased with the presence of the calcitriol.
 Conclusion: In conclusion calcitriol treatment decreased cell proliferation and induced apoptosis in ovarian cancer cells, therefore we can suggest that alone calcitriol or in combination with chemotherapy drugs may be useful for treatment of ovarian cancer.

Design and synthesis of indole-benzimidazole hybrid molecules and evaluation of their in-vitro cytotoxic activities

ABSTRACT. Cancer is one of the most deadly diseases worldwide, challenging the world for effective treatment of the diseases, to tackle this problem a vast amount of therapeutic candidates are being investigated. Indole-benzimidazole structures have recently gained considerable attention, because compounds containing these structure exhibit a very good anticancer property. Two series of novel indole-benzimidazole hybrids molecules viz., 2-(5-substituted-1H-indol-3-yl)-5-substituted-1H-benzo[d]imidazole 5(a-f) and 2-(5-substituted-1-(3-methylbut-2-enyl)-1H-indol-3-yl)-5-substituted-1H-benzo[d]imidazole 6(a-f) were synthesized and characterized by spectroscopic techniques. The twelve target molecules have been investigated for their in-vitro cytotoxic activity against human ovarian carcinoma cells (SKOV-3), human prostate cancer cells (PC-3), human cervical cancer cells (HeLa) and human acute monocytic leukemia cells (THP-1) using MTT assay. Compound; 2-(5-bromo-1H-indol-3-yl)-5-methyl-1H-benzo[d]imidazole (5e) was interesting with IC50 (μM) values of 23.69 (SKOV-3), 73.05 (PC-3), 64.66 (HeLa) and 39.08 (THP-1), respectively.
 
 KEY WORDS: Indole, Benzimidazole, Hybrid molecules, Anticancer activity
 
 Bull. Chem. Soc. Ethiop. 2023, 37(5), 1209-1220. 
 DOI: https://dx.doi.org/10.4314/bcse.v37i5.13

Characterization of global research trends and prospects on platinum-resistant ovarian cancer: a bibliometric analysis.

In the last decades, growing attention has been focused on identifying effective therapeutic strategies in the orphan clinical setting of women with platinum-resistant ovarian cancer (PROC), generating thousands of original articles. However, the literature involving bibliometric analysis of PROC has not been published yet. This study hopes to gain a better understanding of the hot spots and trends in PROC by conducting a bibliometric analysis, as well as identify potential new research directions. We searched the Web of Science Core Collection (WOSCC) for PROC-related articles published between 1990 and 2022. CiteSpace 6.1.R2 and VOS viewer 1.6.18.0 were primarily utilized to evaluate the contribution and co-occurrence relationships of various countries and regions, institutes, and journals and to identify research hotspots and promising future trends in this research field. A total of 3,462 Web of Science publications were retrieved that were published in 671 academic journals by 1135 authors from 844 organizations in 75 countries and regions. The United States was the leading contributor in this field, and the University of Texas MD Anderson Cancer Center was the most productive institution. Gynecologic Oncology was the most productive journal, while the Journal of Clinical Oncology was the most cited and influential. Co-citation cluster labels revealed the characteristics of seven major clusters, including synthetic lethality, salvage treatment, human ovarian-carcinoma cell line, PARP inhibitor resistance, antitumor complexes, folate receptor, and targeting platinum-resistant disease. Keywords and references burst detection indicated that biomarkers, genetic and phenotypic changes, immunotherapy, and targeted therapy were the most recent and most significant aspects of PROC research. This study conducted a comprehensive review of PROC research using bibliometric and visual techniques. Understanding the immunological landscape of PROC and identifying the population that can benefit from immunotherapy, especially in combination with other therapeutic options (such as chemotherapy and targeted therapy), will continue to be the focal point of research.

Tris(aminomethyl)phosphines and Their Copper(I) (Pseudo)halide Complexes with Aromatic Diimines-A Critical Retrospection.

Metal complexes feature a wide range of available geometries, diversified lability, controllable hydrolytic stability, and easily available rich redox activity. These characteristics, combined with the specific properties of coordinated organic molecules, result in many different mechanisms of biological action, making each of the myriads of the classes of metal coordination compounds unique. This focused review presents combined and systematized results of the studies of a group of copper(I) (pseudo)halide complexes with aromatic diimines and tris(aminomethyl)phosphines of a general formula [CuX(NN)PR3], where X = I- or NCS-, NN = 2,2'-bipyridyl, 1,10-phenanthroline, 2,9-dimethyl-1,10-phenanthroline or 2,2'-biquinoline, and PR3 = air-stable tris(aminomethyl)phosphines. The structural and electronic properties of the phosphine ligands and luminescent complexes are discussed. The complexes with 2,9-dimethyl-1,10-phenanthroline, apart from being air- and water-stable, exhibit a very high in vitro antimicrobial activity against the Staphylococcus aureus and Candida albicans. Moreover, some of these complexes also show a strong in vitro antitumor activity against human ovarian carcinoma cell lines: MDAH 2774 and SCOV 3, CT26 (mouse colon carcinoma), and A549 (human lung adenocarcinoma) cell lines. The tested complexes are moderately able to induce DNA lesions through free radical processes, however the trends do not reflect observed differences in biological activity.

Ruthenium(II)–Arene Complexes with Glycosylated NHC-Carbene Co-Ligands: Synthesis, Hydrolytic Behavior, and Binding to Biological Molecules

Ruthenium(II) complexes with a three-legged piano-stool structure based on an arene ring, an N-heterocyclic carbene (NHC)-carbene ligand with a peracetylated glucose moiety and two chlorides or one bidentate ligand, were prepared and characterized by spectroscopy and crystallography. In one case, the sugar substituent is replaced by an ethyl. The chirality of the sugar results in the formation of two diastereomers that interconvert through rotations around the Ccarbene–Ru and Carene–Ru bonds. In water, the complexes undergo a series of equilibrium hydrolysis steps involving the Ru–Cl bonds. The Ru–arene bond and the sugar acetyls are also partially hydrolyzed, and the selectivity of the process is governed by the nature of the arene and the pH of the solution. The reactivity of the compounds was studied against model nucleophiles and biological macromolecules. In the former case, mass experiments demonstrated a variety of binding modes with a trend reflecting the stability in aqueous environment. In the latter case, protein crystallography was used to characterize the preferential binding sites of one of the complexes. The X-ray structure of the adduct formed upon reaction of one representative complex with hen egg white lysozyme contains a Ru center, which retains the carbene ligand, close to the side chain of Asp119. In the adduct with bovine pancreatic ribonuclease, there are two protein molecules in the asymmetric unit. In one molecule, two Ru centers are located close to the side chains of His105 and of His119, which is the protein active site. In the second molecule, only one Ru center was found in the proximity of the side chain of His105. The Ru complexes also interact with calf-thymus DNA, although without displacing the intercalating probe EB. Finally, the complexes are essentially inactive against the human ovarian carcinoma A2780 cells, the cisplatin-resistant A2780cis cells, and the human embryonic kidney HEK293T cells.

Abstract LB234: Activation of the integrated stress response by the developmental HSF1 pathway inhibitor NXP800

Abstract HSF1 is a stress-inducible transcription factor that regulates the eukaryotic heat shock response (HSR). HSF1 activation induces the expression of multiple proteins needed for cellular recovery from stress. HSF1 also plays a key role in tumorigenesis and regulates the expression of a cancer-specific gene signature which is unique to malignant cells and distinct from that activated during the HSR. We discovered NXP800, the first-in-class orally active HSF1 pathway inhibitor which is now undergoing Phase 1 clinical trial, based on a phenotypic pathway screen. Here we employed various techniques to investigate the mechanism of action of NXP800. Using RNAseq in a panel of human carcinoma cell lines, we identified overlapping gene expression changes in response to NXP800. These included genes regulated by HSF1 and interestingly also genes associated with activation of the integrated stress response (ISR). In contrast, we found no evidence for activation of the unfolded protein response. Consistent with the observed NXP800-induced phosphorylation of eIF2α which is a critical regulator of the ISR, NXP800 increased the protein expression of downstream ISR markers ATF4, CHOP and CHAC1, both in human tumor cells in vitro and in human tumor xenograft models in vivo. Induction of the ISR is controlled by four stress-activated protein kinases (PKs) that phosphorylate eIF2α. To further explore these kinases in the mechanism of action of NXP800 we used genetic knockdown by siRNA and inhibition by small-molecule tool compounds. Silencing each of the ISR-regulatory PKs revealed that GCN2 was required for ISR activation by NXP800. This was confirmed using two GCN2 inhibitors from different chemical series. Global phospho-proteome analysis showed that altered protein phosphorylation following NXP800 exposure was reversed upon co-treatment with a GCN2 inhibitor. We also demonstrated that activation of the ISR caused inhibition of HSF1 activation when stimulated with an HSF1 activator, thus confirming the link between ISR induction and inhibition of HSF1 activation. Activation of GCN2 and the ISR can occur in response to a variety of stimuli including amino acid deprivation. However, we did not detect a difference in the uptake of amino acids following exposure to NXP800, indicating that NXP800 does not directly impair amino acid uptake. Using an siRNA approach to determine if activation of the ISR components was contributing to growth inhibition following NXP800 exposure, we found that blocking the induction of ATF4 reduced the response of NXP800-sensitive SK-OV-3 human ovarian carcinoma cells to NXP800 treatment. In summary, NXP800 acts on cancer cells to induce activation of the ISR pathway via GCN2, which then leads to inhibition of HSF1 activation. Further studies are underway to determine the precise molecular target of NXP800 and the mechanism of HSF1 pathway inhibition. Citation Format: Marissa V. Powers, Swee Y. Sharp, Eirini-Maria Lampraki, Toby Roe, Loredana Pellegrino, Maria Taskinen, Robert te Poele, Florence Raynaud, Suzanne Eccles, Matthew Cheeseman, Keith Jones, Paul A. Clarke, Paul Workman. Activation of the integrated stress response by the developmental HSF1 pathway inhibitor NXP800 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr LB234.

Abstract 6020: The role of TP53 mutation status in the response to DNA methyltransferase inhibitor treatment

Abstract The purpose of this study was to understand the effect of p53 mutation status in ovarian cancer cells on the expression of repetitive elements (REs) following epigenetic treatment. High-grade serous ovarian carcinoma is the most aggressive subtype of ovarian cancer and the 5 year survival rate has remained unchanged for over two decades. Over 90% of high-grade serous ovarian carcinoma (OC) patients have a mutation in the TP53 gene, which encodes the p53 protein. P53 is a transcription factor primarily involved in maintaining genome integrity, but it can also regulate the expression of REs in the genome. REs account for more than half of the genome and these repetitive genomic elements are epigenetically silenced in healthy cells to prevent genome instability. The expression of some REs, such as long interspersed nuclear elements and endogenous retroviruses, are upregulated in human OC patients and cell lines. The mechanism by which p53 regulates expression of REs is not well-understood; the literature documents some instances of p53 activating RE transcription and others of p53 repressing RE transcription, depending on the target elements. We have previously shown that RE expression can be induced by treating OC cells with low doses of DNA methyltransferase inhibitors (DNMTis). Recently, we showed that OC cell lines with mutant p53 have higher baseline expression of REs compared to wild type (WT) cell lines. Treatment of TP53 mutant OC cell lines with DNMTis had a muted effect on RE expression compared to treatment of WT OC cell lines. To explore the relationship between TP53 mutation status and RE expression after DNMTi treatment, OC cell lines with different p53 mutation statuses were treated with 500 nM of the DNMTi 5-azacytidine. We then analyzed the expression of several REs via RT-qPCR and western blot. We hypothesized that TP53 mutant cell lines would have lower DNMTi upregulation of REs than TP53 WT cell lines. While at the RNA level RE expression was variable, at the protein level, we found that DNMTi treatment increased protein levels of several REs in TP53 WT and mutant, but not null, OC cell lines. Future work will examine the feasibility of utilizing these RE proteins as immunotherapy targets in OC. Citation Format: Khadra K. Omar, Erin E. Grundy, Olivia Cox, Melissa Hadley, Katherine B. Chiappinelli. The role of TP53 mutation status in the response to DNA methyltransferase inhibitor treatment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6020.