Lovastatin enhances chemosensitivity of paclitaxel-resistant prostate cancer cells through inhibition of CYP2C8

An update understanding of stemness and chemoresistance of prostate cancer

INTRODUCTION

Globally, prostate cancer (CaP) is a leading cause of death and disability among men and a substantial public health burden. Despite advancements in cancer treatment, chemoresistance remains a significant issue in cancer therapy, accounting for the majority of patient relapses and poor survival. Cancer stem cells (CSCs) are considered the main cause of cancer recurrence, chemoresistance, and poor survival of patients. These CSCs acquire stemness and chemoresistance by certain mechanisms such as enhanced DNA repair processes, increased expression of drug efflux pumps, resistance to apoptosis, and altered cell cycle and tumor microenvironment (TME).

AREA COVERED

We cover the latest developments in this field and give an overview of future research directions.

EXPERT OPINION

CSCs show dysregulation of several signaling pathways, mostly related to conferring chemoresistance phenotype, such as high drug efflux, apoptotic resistance, quiescent cell cycle, tumor microenvironment, and DNA repair. There are several research articles published on this topic. However, still, this field warrants further investigations to identify the therapeutic molecule that can either chemosensitize CSCs or kill them effectively. This can only be possible when we know the complete mechanisms to comprehend the fundamental causes of cancer stemness and therapy resistance.

In vitro models to evaluate multidrug resistance in cancer cells: Biochemical and morphological techniques and pharmacological strategies

The overexpression of ATP-binding cassette (ABC) transporters contributes to the failure of chemotherapies and symbolizes a great challenge in oncology, associated with the adaptation of tumor cells to anticancer drugs such that these transporters become less effective, a mechanism known as multidrug resistance (MDR). The aim of this review is to present the most widely used methodologies for induction and comprehension of in vitro models for detection of multidrug-resistant (MDR) modulators or inhibitors, including biochemical and morphological techniques for chemosensitivity studies. The overexpression of MDR proteins, predominantly, the subfamily glycoprotein-1 (P-gp or ABCB1) multidrug resistance, multidrug resistance-associated protein 1 (MRP1 or ABCCC1), multidrug resistance-associated protein 2 (MRP2 or ABCC2) and cancer resistance protein (ABCG2), in chemotherapy-exposed cancer lines have been established/investigated by several techniques. Amongst these techniques, the most used are (i) colorimetric/fluorescent indirect bioassays, (ii) rhodamine and efflux analysis, (iii) release of 3,30-diethyloxacarbocyanine iodide by fluorescence microscopy and flow cytometry to measure P-gp function and other ABC transporters, (iv) exclusion of calcein-acetoxymethylester, (v) ATPase assays to distinguish types of interaction with ABC transporters, (vi) morphology to detail phenotypic characteristics in transformed cells, (vii) molecular testing of resistance-related proteins (RT-qPCR) and (viii) 2D and 3D models, (ix) organoids, and (x) microfluidic technology. Then, in vitro models for detecting chemotherapy MDR cells to assess innovative therapies to modulate or inhibit tumor cell growth and overcome clinical resistance. It is noteworthy that different therapies including anti-miRNAs, antibody-drug conjugates (to natural products), and epigenetic modifications were also considered as promising alternatives, since currently no anti-MDR therapies are able to improve patient quality of life. Therefore, there is also urgency for new clinical markers of resistance to more reliably reflect in vivo effectiveness of novel antitumor drugs.

Interleukin expression patterns and immune cell infiltration in prostate adenocarcinoma: Implications for recurrence risk

OBJECTIVE

This study aims to comprehensively investigate the expression profiles of interleukins in prostate adenocarcinoma (PRAD) and their relationship with immune cell infiltration, tumor progression, and patient prognosis. By establishing an interleukin-related risk score, we seek to enhance the understanding of the tumor immune microenvironment and facilitate the development of tailored immunotherapeutic strategies for PRAD patients.

INTRODUCTION

Interleukins can nurture a tumor promoting environment and simultaneously regulate immune cell infiltration. However, the potential roles of interleukins in the prostate adenocarcinoma immune landscape remain abstruse.

METHODS

We comprehensively investigated the interleukin expression patterns and tumor immune landscape of prostate adenocarcinoma patients. And explored the interleukin expression patterns with immune infiltration landscape. The interleukin score was established using LASSO cox regression analysis. Multivariate Cox regression analysis was employed to assess the prognostic value of the interleukin score.

RESULTS

We identified two distinct interleukin clusters, characterized by different immune cell infiltration, tumor promoting signaling pathways activation and prognosis. The interleukin score was established to estimate the prognosis of individual prostate adenocarcinoma (PRAD) patient. Further analysis demonstrated that the interleukin score was an independent prognostic factor of PRAD. Finally, we investigated the predictive value of interleukin score in the programmed cell death protein (PD-1) blockade therapy of patients with prostate adenocarcinoma. At the same time, the differences in related genes among different prostate cell lines were also identified.

CONCLUSIONS

This study demonstrated the correlation between interleukin and tumor immune landscape in prostate adenocarcinoma. The comprehensive evaluation of interleukin expression patterns in individual prostate patients contribute to our understanding of the immune landscape and helps clinicians selecting proper immunotherapy strategies for prostate patients.

Tetramethylpyrazine attenuates the cancer stem cell like-properties and doxorubicin resistance by targeting HMGCR in breast cancer

BACKGROUND

Tetramethylpyrazine (TMP), a key bioactive constituent derived from Ligusticum wallichii Franchat, has demonstrated efficacy in mitigating multidrug resistance (MDR) in human breast cancer (BC) cells. However, the precise mechanisms underlying its action remain poorly understood.

PURPOSE

Cancer stem cells (CSCs) are widely recognized as the primary contributors to MDR. This investigation seeks to elucidate the role and mechanisms through which TMP counteracts MDR by attenuating CSC-like characteristics.

METHODS

Various assays, including flow cytometry, sphere formation, and Western blotting, were employed to evaluate TMP's effects on breast cancer stem cell (BCSC)-like phenotypes in vitro. In vivo, extreme limiting dilution assays and immunohistochemistry (IHC) were executed to assess the impacts of TMP on BCSC frequency and the levels of stemness markers. Mechanistically, RNA sequencing was performed to uncover the key biological processes involved in TMP's effects on BCSCs. Further experiments, encompassing micro scale thermophoresis (MST), drug affinity responsive target stability (DARTS), cellular thermal shift assay (CETSA) and amino acid mutation analyses, were utilized to identify the essential targets and corresponding binding sites of TMP. Finally, the effects of TMP on BCSC-like phenotypes were confirmed using cells with mutated amino acid residues, which allowed us to investigate the specificity of TMP's binding sites. To further evaluate the impact of TMP on drug resistance, doxorubicin-resistant MCF7 (MCF-7ADR) cells, along with corresponding cell lines harboring mutated amino acid residues, were employed.

RESULTS

TMP was found to inhibit BCSC-like properties both in vitro and in vivo, evidenced by a reduction in the CD44+/CD24- population, sphere formation capability, and expression of stemness markers. Mechanistic studies revealed that TMP targets 3‑hydroxy-3-methylglutaryl-CoA reductase (HMGCR), a rate-limiting enzyme in cholesterol biosynthesis. TMP binds to Asp-767 of HMGCR, thereby inhibiting its activity and reducing cholesterol synthesis. The influence of TMP on BCSC-like phenotypes was nullified by overexpression of wild-type HMGCR, while mutations in the binding site of HMGCR had no effect on TMP's inhibition of BCSC-like properties. Additionally, TMP mitigated MDR by targeting HMGCR.

CONCLUSION

These findings suggest that TMP alleviates MDR by reducing BCSC-like traits through targeting HMGCR and disruption of cholesterol biosynthesis in BC. This provides new insights into the mechanisms through which TMP alleviates MDR and offers new lead compound for exploring HMCGR antagonists.

lncRNAs as prognostic markers and therapeutic targets in cuproptosis-mediated cancer

Long non-coding RNAs (lncRNAs) have emerged as crucial regulators in various cellular processes, including cancer progression and stress response. Recent studies have demonstrated that copper accumulation induces a unique form of cell death known as cuproptosis, with lncRNAs playing a key role in regulating cuproptosis-associated pathways. These lncRNAs may trigger cell-specific responses to copper stress, presenting new opportunities as prognostic markers and therapeutic targets. This paper delves into the role of lncRNAs in cuproptosis-mediated cancer, underscoring their potential as biomarkers and targets for innovative therapeutic strategies. A thorough review of scientific literature was conducted, utilizing databases such as PubMed, Google Scholar, and ScienceDirect, with search terms like 'lncRNAs,' 'cuproptosis,' and 'cancer.' Studies were selected based on their relevance to lncRNA regulation of cuproptosis pathways and their implications for cancer prognosis and treatment. The review highlights the significant contribution of lncRNAs in regulating cuproptosis-related genes and pathways, impacting copper metabolism, mitochondrial stress responses, and apoptotic signaling. Specific lncRNAs are potential prognostic markers in breast, lung, liver, ovarian, pancreatic, and gastric cancers. The objective of this article is to explore the role of lncRNAs as potential prognostic markers and therapeutic targets in cancers mediated by cuproptosis.

Obesity-Associated Colorectal Cancer

Colorectal cancer (CRC) affects approximately 2 million people worldwide. Obesity is the major risk factor for CRC. In addition, obesity contributes to a chronic inflammatory stage that enhances tumor progression through the secretion of proinflammatory cytokines. In addition to an increased inflammatory response, obesity-associated cancer presents accrued molecular factors related to cancer characteristics, such as genome instability, sustained cell proliferation, telomere dysfunctions, angiogenesis, and microbial alteration, among others. Despite the evidence accumulated over the last few years, the treatments for obesity-associated CRC do not differ from the CRC treatments in normal-weight individuals. In this review, we summarize the current knowledge on obesity-associated cancer, including its epidemiology, risk factors, molecular factors, and current treatments. Finally, we enumerate possible new therapeutic targets that may improve the conditions of obese CRC patients. Obesity is key for the development of CRC, and treatments resulting in the reversal of obesity should be considered as a strategy for improving antineoplastic CRC therapies.

Synergistic effects of epoxyazadiradione (EAD) and paclitaxel against triple-negative breast cancer cells

BACKGROUND

Triple-negative breast cancer (TNBC) is the most aggressive and chemo-resistant form of breast cancer subtype, and chemotherapy is a vital treatment option for that. Paclitaxel is an effective chemo drug for TNBC. However, in clinical settings, paclitaxel has adverse side effects. The synergistic combination is the most promising method for overcoming undesirable toxicity and achieving a beneficial therapeutic outcome. Previous reports, including our study, showed certain anticancer potential of epoxyazadiradione (EAD), the neem limonoid, in different types of cancer cells, including TNBC.

OBJECTIVE

This study was designed to investigate the possible synergistic effects of EAD and paclitaxel against TNBC cells.

METHODS

We examined the effects of EAD and paclitaxel alone and in combination in MDA-MB 231 cells, and the percentage cytotoxicity was used to calculate synergism. Characteristic apoptotic changes were observed by visualizing cellular morphology, nuclear fragmentation and membrane integrity. We further estimated anti-migratory potential of experimental compounds by wound healing assay. The reduction in inflammation during combinatorial treatment was evaluated by observing NF-κB translocation.

RESULTS

The combined treatment with EAD (5 μM) and paclitaxel (5 nM), which were used at doses lower than their individual IC50 concentrations, showed a synergistic effect in MDA-MB-231 cells. This combination effectively induced apoptosis and antimigration and reduced the inflammatory reactions induced by the higher dose of paclitaxel.

CONCLUSION

To conclude, EAD could be the drug of choice for combined treatment with paclitaxel in a chemotherapy regimen.

Zinc Oxide Nanoparticles and Cancer Chemotherapy: Helpful Tools for Enhancing Chemo-sensitivity and Reducing Side Effects?

Cancer chemotherapy is still a serious challenge. Chemo-resistance and destructive side effects of chemotherapy drugs are the most critical limitations of chemotherapy. Chemo-resistance is the leading cause of chemotherapy failure. Chemo-resistance, which refers to the resistance of cancer cells to the anticancer effects of chemotherapy drugs, is caused by various reasons. Among the most important of these reasons is the increase in the efflux of chemotherapy drugs due to the rise in the expression and activity of ABC transporters, the weakening of apoptosis, and the strengthening of stemness. In the last decade, a significant number of studies focused on the application of nanotechnology in cancer treatment. Considering the anti-cancer properties of zinc, zinc oxide nanoparticles have received much attention in recent years. Some studies have indicated that zinc oxide nanoparticles can target the critical mechanisms of cancer chemo-resistance and enhance the effectiveness of chemotherapy drugs. These studies have shown that zinc oxide nanoparticles can reduce the activity of ABC transporters, increase DNA damage and apoptosis, and attenuate stemness in cancer cells, leading to enhanced chemo-sensitivity. Some other studies have also shown that zinc oxide nanoparticles in low doses can be helpful in minimizing the harmful side effects of chemotherapy drugs. In this article, after a brief overview of the mechanisms of chemo-resistance and anticancer effects of zinc, we will review all these studies in detail.

Pathological and pharmacological functions of the metabolites of polyunsaturated fatty acids mediated by cyclooxygenases, lipoxygenases, and cytochrome P450s in cancers

Oxylipins have garnered increasing attention because they were consistently shown to play pathological and/or pharmacological roles in the development of multiple cancers. Oxylipins are the metabolites of polyunsaturated fatty acids via both enzymatic and nonenzymatic pathways. The enzymes mediating the metabolism of PUFAs include but not limited to lipoxygenases (LOXs), cyclooxygenases (COXs), and cytochrome P450s (CYPs) pathways, as well as the down-stream enzymes. Here, we systematically summarized the pleiotropic effects of oxylipins in different cancers through pathological and pharmacological aspects, with specific reference to the enzyme-mediated oxylipins. We discussed the specific roles of oxylipins on cancer onset, growth, invasion, and metastasis, as well as the expression changes in the associated metabolic enzymes and the associated underlying mechanisms. In addition, we also discussed the clinical application and potential of oxylipins and related metabolic enzymes as the targets for cancer prevention and treatment. We found the specific function of most oxylipins in cancers, especially the underlying mechanisms and clinic applications, deserves and needs further investigation. We believe that research on oxylipins will provide not only more therapeutic targets for various cancers but also dietary guidance for both cancer patients and healthy humans.

Lipid metabolism, amino acid metabolism, and prostate cancer: a crucial metabolic journey

Prostate cancer (PCa) is one of the most common malignancies in males worldwide, and its development and progression involve the regulation of multiple metabolic pathways. Alterations in lipid metabolism affect the proliferation and metastatic capabilities of PCa cells. Cancer cells increase lipid synthesis and regulate fatty acid oxidation to meet their growth and energy demands. Similarly, changes occur in amino acid metabolism in PCa. Cancer cells exhibit an increased demand for specific amino acids, and they regulate amino acid transport and metabolic pathways to fulfill their proliferation and survival requirements. These changes are closely associated with disease progression and treatment response in PCa cells. Therefore, a comprehensive investigation of the metabolic characteristics of PCa is expected to offer novel insights and approaches for the early diagnosis and treatment of this disease.

Optimization of L-glutaminase production by Monascus ruber URM 8542 isolated from ice cream industrial effluent

L-glutaminase is a hydrolytic enzyme with wide biotechnological applications. Mostly, these enzymes are employed in the feed industry for flavor enhancement and acrylamide mitigation. Also, L-glutaminase may have antiviral and antineoplastic effects making it a good choice for pharmaceutical applications. In this study, the strain Monascus ruber URM 8542 was identified through classical and molecular taxonomy using partial sequencing of β-tubulin and calmodulin genes. Subsequently, the optimal culture conditions were evaluated by submerged fermentation (L-glutamine 10 g.L- 1) for L-glutaminase excretion. The isolate was identified as M. ruber URM 8542 which showed significant extracellular enzyme production with a yield of 11.4 times in relation to the specific activity of intracellular L-glutaminase. Regarding the optimization experiments, several factors such as L-glutamine concentration, temperature, and pH were compared using a full factorial design (23). The concentrations greater than 1% proved to be significantly better for glutaminase production (R2 = 0.9077). Additionally, the L-glutaminase was optimally active at pH 7.0 and 30 ºC. The L-glutaminase was remarkably stable across an alkaline pH range (7.0-8.0) and had a thermal stability ranging from 30 ºC to 60 ºC for 1 h. Taken together, these findings suggest that the L-glutaminase produced by M. ruber is a promising candidate for pharmacological application, although further studies need to be performed. To the best of our knowledge, this is the first report of L-glutaminase production by Monascus ruber.

A Cross-Talk about Radioresistance in Lung Cancer-How to Improve Radiosensitivity According to Chinese Medicine and Medicaments That Commonly Occur in Pharmacies

Lung cancer is one of the most common cancers in the population and is characterized by non-specific symptoms that delay the diagnosis and reduce the effectiveness of oncological treatment. Due to the difficult placement of the tumor, one of the main methods of lung cancer treatment is radiotherapy, which damages the DNA of cancer cells, inducing their apoptosis. However, resistance to ionizing radiation may develop during radiotherapy cycles, leading to an increase in the number of DNA points of control that protect cells from apoptosis. Cancer stem cells are essential for radioresistance, and due to their ability to undergo epithelial-mesenchymal transition, they modify the phenotype, bypassing the genotoxic effect of radiotherapy. It is therefore necessary to search for new methods that could improve the cytotoxic effect of cells through new mechanisms of action. Chinese medicine, with several thousand years of tradition, offers a wide range of possibilities in the search for compounds that could be used in conventional medicine. This review introduces the potential candidates that may present a radiosensitizing effect on lung cancer cells, breaking their radioresistance. Additionally, it includes candidates taken from conventional medicine-drugs commonly available in pharmacies, which may also be significant candidates.

Rottlerin renders a selective and highly potent CYP2C8 inhibition to impede EET formation for implication in cancer therapy

CYP2C8 is a crucial CYP isoform responsible for the metabolism of xenobiotics and endogenous molecules. CYP2C8 converts arachidonic acid to epoxyeicosatrienoic acids (EETs) that cause cancer progression. Rottlerin possess significant anticancer actions. However, information on its CYP inhibitory action is lacking in the literature and therefore, we aimed to explore the same using in silico, in vitro, and in vivo approaches. Rottlerin showed highly potent and selective CYP2C8 inhibition (IC₅₀ < 0.1 μM) compared to negligible inhibition (IC₅₀ > 10 μM) for seven other experimental CYPs in human liver microsomes (HLM) (in vitro) using USFDA recommended index reactions. Mechanistic studies reveal that rottlerin could reversibly (mixed-type) block CYP2C8. Molecular docking (in silico) results indicate a strong interaction could occur between rottlerin and the active site of human CYP2C8. Rottlerin boosted the plasma exposure of repaglinide and paclitaxel (CYP2C8 substrates) by delaying their metabolism using the rat model (in vivo). Multiple-dose treatment of rottlerin with CYP2C8 substrates lowered the CYP2C8 protein expression and up-regulated & down-regulated the mRNA for CYP2C12 and CYP2C11 (rat homologs), respectively, in rat liver tissue. Rottlerin substantially hindered the EET formation in HLM. Overall results of rottlerin on CYP2C8 inhibition and EET formation insinuate further exploration for targeted cancer therapy.

Cytochrome P450-mediated herb-drug interaction (HDI) of Polygonum multiflorum Thunb. based on pharmacokinetic studies and in vitro inhibition assays

BACKGROUND

Polygonum multiflorum Thunb. (PM) is well known both in China and other countries of the world for its tonic properties, however, it has lost its former glory due to liver toxicity incidents in recent years.

PURPOSE

The purpose of this study is to determine whether the occurrence of herb-drug interaction (HDI) caused by PM is associated with cytochrome P450 (CYP450) based on pharmacokinetic studies and in vitro inhibition assays. The objective was to provide a reference for the rational and safe use of drugs in clinical practice.

METHODS

In this study, raw PM (R), together with its two processed products which included PM by Chinese Pharmacopoeia (M) and PM by "nine cycles of steaming and sunning (NCSS)" ("9"), were prepared as the main research objects. A method based on fluorescence technology was used to evaluate the inhibition levels of raw and processed PMs, as well as corresponding characteristic compounds on seven recombinant human cytochrome P450s (rhCYP450s). The pharmacokinetics of sulindac (a representative of commonly used nonsteroidal anti-inflammatory drugs) and psoralen (a major compound of Psoralea in combination with PM) in rat plasma were studied when combined with raw and different processed products of PM.

RESULTS

The inhibitory level order of the three extracts on major different subtypes of CYP450 (CYP1A2, CYP2B6, CYP2C8, CYP2C19, CYP2D6, and CYP3A4) was: R > M > "9". However, the inhibition level of R and "9" is higher than that of M on CYP2C9. Further studies showed that trans-THSG and emodin could selectively inhibit CYP3A4 and CYP1A2, respectively. Epicatechin gallate mainly inhibited CYP3A4 and CYP1A2, followed by CYP2C8 and CYP2C9. Genistein mainly inhibited CYP3A4, followed by CYP2C9 and CYP2C8. CYP3A4 and CYP2C9 were also inhibited by daidzein. The inhibitory effects of all the PM extracts were associated with their characteristic compounds. The results of HDI showed that R increased sulindac exposure to rat blood, and R and M increased psoralen exposure to rat blood, which were consistent with corresponding metabolic enzymes. Overall, the in vitro and in vivo results indicated that PM, especially R, would be at high risk to cause toxicity and drug interactions via CYP450 inhibition.

CONCLUSION

This study not only elucidates the scientific connotation of "efficiency enhancement and toxicity reduction" of PM by NCSS from the perspective of metabolic inhibition but also contributes to HDI prediction and appropriate clinical medication of PM.

Paclitaxel and docetaxel resistance in prostate cancer: Molecular mechanisms and possible therapeutic strategies

Prostate cancer is among most malignant tumors around the world and this urological tumor can be developed as result of genomic mutations and their accumulation during progression towards advanced stage. Due to lack of specific symptoms in early stages of prostate cancer, most cancer patients are diagnosed in advanced stages that tumor cells display low response to chemotherapy. Furthermore, genomic mutations in prostate cancer enhance the aggressiveness of tumor cells. Docetaxel and paclitaxel are suggested as well-known compounds for chemotherapy of prostate tumor and they possess a similar function in cancer therapy that is based on inhibiting depolymerization of microtubules, impairing balance of microtubules and subsequent delay in cell cycle progression. The aim of current review is to highlight mechanisms of paclitaxel and docetaxel resistance in prostate cancer. When oncogenic factors such as CD133 display upregulation and PTEN as tumor-suppressor shows decrease in expression, malignancy of prostate tumor cells enhances and they can induce drug resistance. Furthermore, phytochemicals as anti-tumor compounds have been utilized in suppressing chemoresistance in prostate cancer. Naringenin and lovastatin are among the anti-tumor compounds that have been used for impairing progression of prostate tumor and enhancing drug sensitivity. Moreover, nanostructures such as polymeric micelles and nanobubbles have been utilized in delivery of anti-tumor compounds and decreasing risk of chemoresistance development. These subjects are highlighted in current review to provide new insight for reversing drug resistance in prostate cancer.

The Role of procollagen type 1 amino-terminal propertied (P1NP) Cytochrome P450 (CYPs) and Osteoprotegerin (OPG) as Potential Bone function markers in Prostate Cancer Bone Metastasis

Background: Procollagen type I amino-terminal propeptide (PINP) is often present during osteoblast development and could be a biomarker of early bone development. Osteoprotegerin (OPG) may protect tumor cells from apoptosis. Cytochrome P450 enzymes help tumor development and treatment (CYPs). Cytochrome P450 activates and deactivates anticancer drugs and procarcinogens.

Objective: The study examined the amounts of a diagnostic marker of bone formation, the amino terminal propeptide of type I procollagen (PINP), Osteoprotegerin (OPG), and P450, in prostate cancer patients at different stages and its ability to detect osteoblastic metastases.

Methods: ELISA was used to measure PINP, OPG, and P450 levels in 30 prostate cancer patients. (n = 32) and healthy men’s serum (n = 36).

Results: Prostate cancer patients had higher blood levels of PINP, OPG, and P450 than healthy persons (301.3±134.9, 980±467.2, and 84.2±28.4 pg/mL, respectively). Compared to I+II prostate cancer patients, III+IV patients showed higher serum PINP, OPG, and P450 levels (P 0.001). OPG, P450, and PINP had statistically significant Area under the ROC curve (0.9467, P= 0.0001, 0.91, P= 0.0001, and 0.6977, P= 0.4035) in prostate cancer patients.

Conclusions: Metastatic prostate cancer patients had greater PINP, OPG, and P450 levels, according to our findings. PINP, OPG, and P450 levels may affect prostate cancer progression. These findings imply that serum PINP, OPG, and P450 levels may predict and diagnose prostate cancer.

A comprehensive gene expression profile analysis of prostate cancer cells resistant to paclitaxel and the potent target to reverse resistance

Background: Paclitaxel resistance is the major clinical obstacle in the chemotherapy of prostate cancer (PCa), but the resistant mechanism is less investigated.Purpose: To establish two paclitaxel-resistant PCa cells, provide a comprehensive gene expression profile analysis of resistant cells and the potential target to reverse resistance.Methods: Two Paclitaxel-resistant PCa cells (PC3/PR, LNcap/PR) were established by gradually increasing drug concentration. MTT and transwell assays were performed to detect drug sensitivity, cell proliferation and migration abilities. RNA-Sequencing (RNA-seq) and bioinformatic analyses were performed to identify abnormally expressed genes (AEGs) in resistant cells, and annotate the biological functions of AEGs. The role of the candidate AEG, TLR-4, on the resistant phenotypes was further investigated.Results: The resistance index of resistant cells was 2-3, and they showed a slower proliferation and increased migration ability. 4741 AEGs were screened out (Log2fold change absolute: log2FC(abs)  > 1) in the resistant cells, and they were enriched in 2'-5'-oligoadenylate synthetase activity and chemical carcinogenesis. A number of AEGs, CCND2, IGFBP3, FOS, SHH, ZEB2, and members of FGF, FGFR and WNT families were also identified to be involved in cancer- and resistant phenotype-related processes. Finally, TLR-4 was validated significantly increased in resistant cells, and knockdown of TLR-4 increased drug-sensitivity, inhibited the proliferation and migration abilities.Conclusions: The study provided a comprehensive gene expression profile of paclitaxel-resistant PCa cells, and TLR-4 could be a potential target to reverse paclitaxel resistance.