The Wnt non-canonical signaling modulates cabazitaxel sensitivity in prostate cancer cells

Combinatorial Effects of Free and Nanoencapsulated Forms of Cabazitaxel and RAS-Selective Lethal 3 in Breast Cancer Cells

Background: Combination therapies for cancer have gained considerable attention due to their potential for enhancing therapeutic efficacy and decreasing drug resistance. Introducing nanodrug delivery systems in this context may further improve the therapy due to targeted delivery, improved drug stability, sustained drug release, and prevention of rapid clearance from circulation. This study evaluates the combinatorial effects of two cytotoxic drugs, cabazitaxel (CBZ) and RSL3 (RAS-selective lethal 3), in free form as well as encapsulated within poly(2-ethyl butyl cyanoacrylate) (PEBCA) nanoparticles (NPs) in breast cancer cell lines. Methods: Cell proliferation was assessed using IncuCyte technology, and synergistic drug effects were determined with SynergyFinder Plus. Cell viability was measured with the MTT assay. Additionally, we investigated whether the combinatorial effects were reflected in alterations of metabolic activity or reactive oxygen species (ROS) production using Seahorse technology and the CM-H2DCFDA assay, respectively. Results: The data presented reveal, for the first time, that CBZ and RSL3 exhibit synergistically or additively combinatorial effects on various breast cancer cell lines. The pattern of cytotoxic effects was consistent, whether the drugs were in free form or encapsulated in NPs. Moreover, the combinatorial effects were not observed to be associated with early changes in metabolic activity or ROS production. Conclusion: This study highlights the potential of CBZ and RSL3 in combinatorial nanomedicine as they may act synergistically. Further studies are warranted to better understand the mechanisms behind these combinatorial effects.

Novel insights into taxane pharmacology: An update on drug resistance mechanisms, immunomodulation and drug delivery strategies

Taxanes are effective in several solid tumors. Paclitaxel, the main clinically available taxane, was approved in the early nineties, for the treatment of ovarian cancer and later on, together with the analogs docetaxel and cabazitaxel, for other malignancies. By interfering with microtubule function and impairing the separation of sister cells at mitosis, taxanes act as antimitotic agents, thereby counteracting the high proliferation rate of cancer cells. The action of taxanes goes beyond their antimitotic function because their main cellular targets, the microtubules, participate in multiple processes such as intracellular transport and cell shape maintenance. The clinical efficacy of taxanes is limited by the development of multiple resistance mechanisms. Among these, extracellular vesicles have emerged as new players. In addition, taxane metronomic schedules shows an impact on the tumor microenvironment reflected by antiangiogenic and immunomodulatory effects, an aspect of growing interest considering their inclusion in treatment regimens with immunotherapeutics. Preclinical studies have paved the bases for synergistic combinations of taxanes both with conventional and targeted agents. A variety of drug delivery strategies have provided novel opportunities to increase the drug activity. The ability of taxanes to orchestrate different cellular effects amenable to modulation suggests novel options to improve cures in lethal malignancies.

Association between the apoptotic effect of Cabazitaxel and its pro-oxidant efficacy on the redox adaptation mechanisms in prostate cancer cells with different resistance phenotypes

Redox adaptation causes poor prognosis by adapting cancer cells to excessive oxidative stress. Previously, we introduced an oxidative stress-resistant metastatic prostate cancer (mPC) model (LNCaP-HPR) that redox adaptation reduced the effect of Cabazitaxel (Cab), the last taxane-derivative for metastatic castration-resistant PC (mCRPC). Whereas, we investigated for the first time whether there is an association between the altered apoptotic effect and pro-oxidant efficacy of Cab on the redox adaptation in PC cells with different phenotypes, including LNCaP mPC, LNCaP-HPR, C4-2 mCRPC, and RWPE-1 cells. Cab was shown pro-oxidant efficacy proportionally with the apoptotic effect, more prominent in the less aggressive LNCaP cells, by increasing the endogenous ROS, mitochondrial damage, and inhibiting nuclear ROS scavengers, p-Nrf2 and HIF-1α. However, the pro-oxidant and apoptotic effect was lower in the LNCaP-HPR and C4-2 cells, indicating that the drug sensitivity of the cells adapted to survive with more ROS was reduced via altered regulation of redox adaptation. Additionally, unlike LNCaP, Cab caused an increase in the p-NF-κB activation, suggesting that the p-NF-κB might accompany maintaining survival with the increased ROS in the aggressive PC cells. Moreover, the cytotoxic and apoptotic effects of Cab were less on RWPE-1 cells compared to LNCaP but were closer to those on the more aggressive LNCaP-HPR and C4-2 cells, except for the changing pro-oxidant effect of Cab. Consequently, this study indicates the variable pro-oxidant effects of Cab on redox-sensitive proteins, which could be a target for improving Cab's apoptotic effect more in aggressive PC cells.

Highlighting function of Wnt signalling in urological cancers: Molecular interactions, therapeutic strategies, and (nano)strategies

Cancer is a complex, multistep process characterized by abnormal cell growth and metastasis as well as the capacity of the tumor cells in therapy resistance development. The urological system is particularly susceptible to a group of malignancies known as urological cancers, where an accumulation of genetic alterations drives carcinogenesis. In various human cancers, Wnt singalling is dysregulated; following nuclear transfer of β-catenin, it promotes tumor progression and affects genes expression. Elevated levels of Wnt have been documented in urological cancers, where its overexpression enhances growth and metastasis. Additionally, increased Wnt singalling contributes to chemoresistance in urological cancers, leading to reduced sensitivity to chemotherapy agents like cisplatin, doxorubicin, and paclitaxel. Wnt upregulation can change radiotherapy response of urological cancers. The regulation of Wnt involves various molecular pathways, including Akt, miRNAs, lncRNAs, and circRNAs, all of which play roles in carcinogenesis. Targeting and silencing Wnt or its associated pathways can mitigate tumorigenesis in urological cancers. Anti-cancer compounds such as curcumin and thymoquinone have shown efficacy in suppressing tumorigenesis through the downregulation of Wnt singalling. Notably, nanoparticles have proven effective in treating urological cancers, with several studies in prostate cancer (PCa) using nanoparticles to downregulate Wnt and suppress tumor growth. Future research should focus on developing small molecules that inhibit Wnt singalling to further suppress tumorigenesis and advance the treatment of urological cancers. Moreover, Wnt can be used as reliable biomarker for the diagnosis and prognosis of urological cancers.

Role of Wnt/β-catenin pathway in cancer drug resistance: Insights into molecular aspects of major solid tumors

Adaptive resistance to conventional and targeted therapies remains one of the major obstacles in the effective management of cancer. Aberrant activation of key signaling mechanisms plays a pivotal role in modulating resistance to drugs. An evolutionarily conserved Wnt/β-catenin pathway is one of the signaling cascades which regulate resistance to drugs. Elevated Wnt signaling confers resistance to anticancer therapies, either through direct activation of its target genes or via indirect mechanisms and crosstalk over other signaling pathways. Involvement of the Wnt/β-catenin pathway in cancer hallmarks like inhibition of apoptosis, promotion of invasion and metastasis and cancer stem cell maintenance makes this pathway a potential target to exploit for addressing drug resistance. Accumulating evidences suggest a critical role of Wnt/β-catenin pathway in imparting resistance across multiple cancers including PDAC, NSCLC, TNBC, etc. Here we present a comprehensive assessment of how Wnt/β-catenin pathway mediates cancer drug resistance in majority of the solid tumors. We take a deep dive into the Wnt/β-catenin signaling-mediated modulation of cellular and downstream molecular mechanisms and their impact on cancer resistance.

Wnt Signaling and Therapeutic Resistance in Castration-Resistant Prostate Cancer

Purpose of Review

Castration-resistant prostate cancer (CRPC) is a lethal form of prostate cancer (PCa) due to the development of resistance to androgen deprivation therapy and anti-androgens. Here, we review the emerging role of Wnt signaling in therapeutic resistance of CRPC.

Recent Findings

Convincing evidence have accumulated that Wnt signaling is aberrantly activated through genomic alterations and autocrine and paracrine augmentations. Wnt signaling plays a critical role in a subset of CRPC and in resistance to anti-androgen therapies. Wnt signaling navigates CRPC through PCa heterogeneity, neuroendocrine differentiation, DNA repair, PCa stem cell maintenance, epithelial-mesenchymal-transition and metastasis, and immune evasion.

Summary

Components of Wnt signaling can be harnessed for inhibiting PCa growth and metastasis and for developing novel therapeutic strategies to manage metastatic CRPC. There are many Wnt pathway-based potential drugs in different stages of pre-clinical development and clinical trials but so far, no Wnt signaling-specific drug has been approved by FDA for clinical use in CRPC.

ROR2 increases the chemoresistance of melanoma by regulating p53 and Bcl2-family proteins via ERK hyperactivation

Background

ROR2 is a tyrosine-kinase receptor whose expression is dysregulated in many human diseases. In cancer, ROR2 stimulates proliferation, survival, migration, and metastasis, and is associated with more aggressive tumor stages. The purpose of this work is to study the role of ROR2 in the chemoresistance of melanoma.

Methods

Gain- and loss-of-function experiments were used to study the biological function of ROR2 in melanoma. Cell death induced by chemotherapeutic drugs and BH-3 mimetics was evaluated using crystal violet cytotoxicity assays and annexin V/propidium iodide staining. Western blots were used to evaluate the expression of proteins implicated in cell death. The differences observed between cells with manipulation of ROR2 levels and control cells were evaluated using both Student’s t-test and ANOVA.

Results

We describe that ROR2 contributes to tumor progression by enhancing the resistance of melanoma cells to both chemotherapeutic drugs and BH-3 mimetics. We demonstrate that ROR2 reduced cell death upon treatment with cisplatin, dacarbazine, lomustine, camptothecin, paclitaxel, ABT-737, TW-37, and venetoclax. This effect was mediated by the inhibition of apoptosis. In addition, we investigated the molecular mechanisms implicated in this role of ROR2. We identified the MDM2/p53 pathway as a novel target of ROR2 since ROR2 positively regulates MDM2 levels, thus leading to p53 downregulation. We also showed that ROR2 also upregulates Mcl-1 and Bcl2-xL while it negatively regulates Bax and Bid expression. The effect of ROR2 on the expression of these proteins is mediated by the hyperactivation of ERK.

Conclusions

These results demonstrate that ROR2 contributes to melanoma progression by inhibiting apoptosis and increasing chemoresistance. These results not only position ROR2 as a marker of chemoresistance but also support its use as a novel therapeutic target in cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s11658-022-00327-7.