Combining the farnesyltransferase inhibitor lonafarnib with paclitaxel results in enhanced growth inhibitory effects on human ovarian cancer models in vitro and in vivo

Antineoplastics for treating Alzheimer's disease and dementia: Evidence from preclinical and observational studies

As the world population ages, there will be an increasing need for effective therapies for aging-associated neurodegenerative disorders, which remain untreatable. Dementia due to Alzheimer's disease (AD) is one of the leading neurological diseases in the aging population. Current therapeutic approaches to treat this disorder are solely symptomatic, making the need for new molecular entities acting on the causes of the disease extremely urgent. One of the potential solutions is to use compounds that are already in the market. The structures have known pharmacokinetics, pharmacodynamics, toxicity profiles, and patient data available in several countries. Several drugs have been used successfully to treat diseases different from their original purposes, such as autoimmunity and peripheral inflammation. Herein, we divulge the repurposing of drugs in the area of neurodegenerative diseases, focusing on the therapeutic potential of antineoplastics to treat dementia due to AD and dementia. We briefly touch upon the shared pathological mechanism between AD and cancer and drug repurposing strategies, with a focus on artificial intelligence. Next, we bring out the current status of research on the development of drugs, provide supporting evidence from retrospective, clinical, and preclinical studies on antineoplastic use, and bring in new areas, such as repurposing drugs for the prion-like spreading of pathologies in treating AD.

Phenothiazine- and Carbazole-Cyanochalcones as Dual Inhibitors of Tubulin Polymerization and Human Farnesyltransferase

In the search for innovative approaches to cancer chemotherapy, a chemical library of 49 cyanochalcones, 1a-r, 2a-o, and 3a-p, was designed as dual inhibitors of human farnesyltransferase (FTIs) and tubulin polymerization (MTIs) (FTIs/MTIs), two important biological targets in oncology. This approach is innovative since the same molecule would be able to interfere with two different mitotic events of the cancer cells and prevent these cells from developing an emergency route and becoming resistant to anticancer agents. Compounds were synthesized by the Claisen-Schmidt condensation of aldehydes with N-3-oxo-propanenitriles under classical magnetic stirring and under sonication. Newly synthesized compounds were screened for their potential to inhibit human farnesyltransferase, tubulin polymerization, and cancer cell growth in vitro. This study allowed for the identification of 22 FTIs and 8 dual FTIs/MTIs inhibitors. The most effective molecule was carbazole-cyanochalcone 3a, bearing a 4-dimethylaminophenyl group (IC₅₀ (h-FTase) = 0.12 µM; IC₅₀ (tubulin) = 0.24 µM) with better antitubulin activity than the known inhibitors that were previously reported, phenstatin and (-)-desoxypodophyllotoxin. The docking of the dual inhibitors was realized in both the active site of FTase and in the colchicine binding site of tubulin. Such compounds with a dual inhibitory profile are excellent clinical candidates for the treatment of human cancers and offer new research perspectives in the search for new anti-cancer drugs.

Targeted therapy for mucinous ovarian carcinoma: evidence from clinical trials

Mucinous ovarian carcinoma is a rare subtype of epithelial ovarian cancer. Despite being a chemoresistant tumour type, surgical resection and chemotherapy are still the current standard for management. This narrative review aims to explore the current evidence for targeted therapies in mucinous ovarian carcinoma. A review of the literature was performed to identify clinical trials and case reports of targeted therapy in patients with mucinous ovarian carcinoma. The databases and registers (PubMed, MEDLINE, Embase, Europe PMC, Cochrane Central Register of Clinical Trials, clinicaltrials.gov) were searched for articles published between January 2009 to June 2021 using keywords specific for mucinous ovarian carcinoma and targeted therapy. Records were screened and assessed for eligibility based on inclusion and exclusion criteria. From 684 records, 21 studies met the criteria to be included in the review. A total of 11 different targeted therapies were identified, each demonstrating varying degrees of clinical evidence supporting further investigation in patients with mucinous ovarian carcinoma. Targeted therapies identified in this review that warrant further investigations are bevacizumab, trastuzumab, nintedanib, AZD1775, sunitinib, cediranib and pazopanib. Many of the therapeutic agents may be investigated further in combination with other targeted therapies or chemotherapy. More clinical trials focusing on targeted therapy specifically in patients with mucinous ovarian cancer are required to inform clinical use. Multinational efforts are likely to be required to successfully conduct trials in this rare tumor type.

The FNTB promoter polymorphism rs11623866 as a potential predictive biomarker for lonafarnib treatment of ovarian cancer patients

AIM

Despite promising preclinical findings regarding clinical utility of farnesyltransferase inhibitors (FTI), such as lonafarnib, success of clinical trials is limited. A multicentre AGO-OVAR-15 phase II trial reported an unfavourable effect of lonafarnib on the outcome of patients with advanced ovarian cancer. This study was performed as a genetic subgroup analysis of the AGO-OVAR-15 trial, and investigated the utility of the promoter polymorphism rs11623866 of the farnesyltransferase ß-subunit gene (FNTB) in predicting the clinical effectiveness of lonafarnib.

METHODS

The influence of rs11623866 (c.-609G > C) on FNTB promoter activity was investigated by electrophoretic-mobility-shift assay, luciferase-reporter assay and RT-qPCR. A total of 57 out of 105 patients from the AGO-OVAR-15 trial, treated with carboplatin and paclitaxel ± lonafarnib, was genotyped for rs11623866 by restriction fragment length polymorphism analysis. Genotype-dependent survival analysis was performed by Kaplan-Meier analysis.

RESULTS

The presence of the G allele was associated with increased FNTB promoter activity compared with the C allele. An unfavourable effect of lonafarnib was limited to patients carrying a GG genotype (HRPFS 6.2, 95%CI = 2.01, 19.41, P = 0.002; HROS 9.6, 95%CI = 1.89, 48.54, P = 0.006). Median progression free survival (PFS) for patients with the GG genotype in the lonafarnib treated arm was 10 months, whereas median PFS without FTI-treatment was 40 months. Median overall survival (OS) in the lonafarnib-treated group was 19 months, whereas median OS was not reached in the untreated group.

CONCLUSIONS

Discrepancies between preclinical success and clinical failure may be due to the patients' genetic variability of FNTB. Therefore, our results may encourage retrospective evaluation of FNTB polymorphisms in previous FTI studies, especially those reporting positive FTI response.

Farnesyltransferase inhibitors: CAAX mimetics based on different biaryl scaffolds

Mimetics of the C-terminal CAAX tetrapeptide of Ras protein were designed as farnesyltransferase (FTase) inhibitors (FTIs) by replacing AA with o-aryl or o-heteroaryl substituted p-hydroxy- or p-aminobenzoic acid, while maintaining the replacement of C with 1,4-benzodioxan-2-ylmethyl or 2-amino-4-thiazolylacetyl residue as in previous CAAX mimetics. Both FTase inhibition and antiproliferative effect were showed by two thiazole derivatives, namely those with 1-naphthyl (10 and 10a) or 3-furanyl (15 and 15a) in the central spacer, and by the benzodioxane derivative with 2-thienyl (6 and 6a) in the same position. Accumulation of unprenylated RAS was demonstrated in cells incubated with 15a. Consistently with FTIs literature, such results delineate the biaryl scaffold not only as a spacer but also as a sensible area of these mimetic molecules, where modifications at the branching aromatic ring are not indifferent and should be matter of further investigation.

Evaluating cell lines as tumour models by comparison of genomic profiles

Cancer cell lines are frequently used as in vitro tumour models. Recent molecular profiles of hundreds of cell lines from The Cancer Cell Line Encyclopedia and thousands of tumour samples from the Cancer Genome Atlas now allow a systematic genomic comparison of cell lines and tumours. Here we analyse a panel of 47 ovarian cancer cell lines and identify those that have the highest genetic similarity to ovarian tumours. Our comparison of copy-number changes, mutations and mRNA expression profiles reveals pronounced differences in molecular profiles between commonly used ovarian cancer cell lines and high-grade serous ovarian cancer tumour samples. We identify several rarely used cell lines that more closely resemble cognate tumour profiles than commonly used cell lines, and we propose these lines as the most suitable models of ovarian cancer. Our results indicate that the gap between cell lines and tumours can be bridged by genomically informed choices of cell line models for all tumour types.

Cell lines are widely used in cancer research to study tumour biology. Here Domcke et al. compare genomic data from ovarian cancer cell lines with those from clinical ovarian tumour samples and identify cell lines that most closely resemble the genomic features of high-grade serous ovarian cancer.

Lonafarnib for cancer and progeria

INTRODUCTION

Lonafarnib is a non-peptidomimetic inhibitor of farnesyl transferase, an enzyme responsible for the post-translational lipid modification of a wide variety of cellular proteins that are involved in the pathogenic pathways of various diseases including cancer and progeria. Although extensive clinical research indicates limited activity of lonafarnib in solid tumors, there is recent interest in combinations of farnesyl transferase inhibitors with imatinib or bortezomib in hematological malignancies and to investigate the role of lonafarnib in progeria.

AREAS COVERED

This review examines the in vitro and in vivo pharmacology of lonafarnib and the available clinical data for lonafarnib monotherapy and combination therapy in the treatment of solid and hematological malignancies as well as progeria, using studies identified from the PubMed database supplemented by computerized search of relevant abstracts from major cancer and hematology conferences.

EXPERT OPINION

There is no evidence to support the use of lonafarnib in solid tumors. There is ongoing interest to explore lonafarnib for progeria and to investigate other farnesyl transferase inhibitors for chronic and acute leukemias.

Continuous and intermittent dosing of lonafarnib potentiates the therapeutic efficacy of docetaxel on preclinical human prostate cancer models

Lonafarnib is a potent, selective farnesyltransferase inhibitor (FTI) undergoing clinical studies for the treatment of solid tumors and hematological malignancies. Preclinically, a number of FTIs, including lonafarnib, interact with taxanes to inhibit cancer cell growth in an additive/synergistic manner. These observations provided rationale for investigating the effects of combining lonafarnib and docetaxel on preclinical prostate cancer models. To date, docetaxel is the only chemotherapeutic agent in clinical use for hormone-refractory prostate cancer. In vitro experiments with 22Rv1, LNCaP, DU-145, PC3 and PC3-M prostate cancer cell lines showed significantly enhanced inhibition of cell proliferation and apoptosis when lonafarnib was added to docetaxel. In human tumor xenograft models, continuous coadministration of lonafarnib with docetaxel caused marked tumor regressions (24-47%) in tumors from all of the cell types as well as parental CWR22 xenografts. Intermittent dosing of lonafarnib (5 days on then 5 days off) coadministered with docetaxel produced similar regressions in hormone-refractory 22Rv1 tumors. 22Rv1 tumors progressing on docetaxel treatment also responded to treatment with intermittent lonafarnib (5 days on then 5 days off). Moreover, animals did not exhibit any signs of toxicity during coadministration of lonafarnib and docetaxel. In conclusion, coadministration of continuous and intermittent lonafarnib enhanced the antitumor activity of docetaxel in a panel of prostate cancer models. An intermittent dosing schedule of lonafarnib coadministered with docetaxel may allow enhanced efficacy to that of continuous dosing by improving the tolerability of higher doses of lonafarnib.

Resistance to cisplatin does not affect sensitivity of human ovarian cancer cell lines to mifepristone cytotoxicity

BACKGROUND

The prototypical antiprogestin mifepristone exhibits potent growth inhibition activity towards ovarian cancer cells in vitro and in vivo. The aim of this research was to establish whether mifepristone is capable of inhibiting cell proliferation and inducing apoptotic cell death regardless of the degree of sensitivity ovarian cancer cells exhibit to cisplatin.

METHODS

OV2008, OV2008/C13, A2780, A2780/CP70, Caov-3, and SK-OV-3 cell lines exhibiting a range of sensitivities to cisplatin were used. Growth inhibition, cell viability, and sub-diploid DNA content in response to treatment with escalating doses of either mifepristone or cisplatin were assessed by microcapillary cytometry. Apoptotic cell death was evaluated by measuring genomic DNA fragmentation and cleavage of caspase-3 and poly (ADP ribose) polymerase (PARP).

RESULTS

The sensitivities to cisplatin manifested by the cell lines were OV2008 > A2780 > Caov-3 > SK-OV-3 > OV2008/C13 > A2780/CP70. Mifepristone inhibited the growth of all six cell lines in a dose-related manner with IC50s ranging from ~6-12 muM and without significant correlation with the relative sensitivities the cells displayed for cisplatin. Moreover, at the highest concentration studied, mifepristone triggered apoptotic death in all six cell lines as evidenced by the increase in sub-diploid fragmented DNA content and cleavage of caspase-3 and of its downstream substrate PARP.

CONCLUSION

Mifepristone is cytotoxic towards ovarian cancer cells independent of the sensitivity exhibited by the cells to cisplatin, displaying cytostatic effects at lower concentrations and lethal effects at higher concentrations. Mifepristone monotherapy emerges as a valuable therapeutic alternative for platinum-resistant ovarian cancers.