Genetic polymorphisms and response to 5-fluorouracil, doxorubicin and cyclophosphamide chemotherapy in breast cancer patients

Pharmacogenomics influence on MDR1-associated cancer resistance and innovative drug delivery approaches: advancing precision oncology

Currently, there is a growing concern surrounding the treatment of cancer, a formidable disease. Pharmacogenomics and personalized medicine have emerged as significant areas of interest in cancer management. The efficacy of many cancer drugs is hindered by resistance mechanisms, particularly P-glycoprotein (P-gp) efflux, leading to reduced therapeutic outcomes. Efforts have intensified to inhibit P-gp efflux, thereby enhancing the effectiveness of resistant drugs. P-gp, a member of the ATP-binding cassette (ABC) superfamily, specifically the multidrug resistance (MDR)/transporter associated with antigen processing (TAP) sub-family B, member 1, utilizes energy derived from ATP hydrolysis to drive efflux. This review focuses on genetic polymorphisms associated with P-gp efflux and explores various novel pharmaceutical strategies to address this challenge. These strategies encompass SEDDS/SNEDDS, liposomes, immunoliposomes, solid lipid nanoparticles, lipid core nanocapsules, microemulsions, dendrimers, hydrogels, polymer-drug conjugates, and polymeric nanoparticles. The article aims to elucidate the interplay between pharmacogenomics, P-gp-mediated drug resistance in cancer, and formulation strategies to improve cancer therapy by tailoring formulations to genetically susceptible patients.

Are the Common Genetic 3'UTR Variants in ADME Genes Playing a Role in Tolerance of Breast Cancer Chemotherapy?

We studied the associations between 3'UTR genetic variants in ADME genes, clinical factors, and the risk of breast cancer chemotherapy toxicity. Those variants and factors were tested in relation to seven symptoms belonging to myelotoxicity (anemia, leukopenia, neutropenia), gastrointestinal side effects (vomiting, nausea), nephrotoxicity, and hepatotoxicity, occurring in overall, early, or recurrent settings. The cumulative risk of overall symptoms of anemia was connected with AKR1C3 rs3209896 AG, ERCC1 rs3212986 GT, and >6 cycles of chemotherapy; leukopenia was determined by ABCC1 rs129081 allele G and DPYD rs291593 allele T; neutropenia risk was correlated with accumulation of genetic variants of DPYD rs291583 allele G, ABCB1 rs17064 AT, and positive HER2 status. Risk of nephrotoxicity was determined by homozygote DPYD rs291593, homozygote AKR1C3 rs3209896, postmenopausal age, and negative ER status. Increased risk of hepatotoxicity was connected with NR1/2 rs3732359 allele G, postmenopausal age, and with present metastases. The risk of nausea and vomiting was linked to several genetic factors and premenopausal age. We concluded that chemotherapy tolerance emerges from the simultaneous interaction of many genetic and clinical factors.

Euterpe oleracea extract (açaí) exhibits cardioprotective effects after chemotherapy treatment in a breast cancer model

BACKGROUND

Açaí, a Brazilian native fruit, has already been demonstrated to play a role in the progress of breast cancer and cardiotoxicity promoted by chemotherapy agents. Thus, the present study aimed to evaluate the combined use of açaí and the FAC-D chemotherapy protocol in a breast cancer model in vivo.

METHODS

Mammary carcinogenesis was induced in thirty female Wistar rats by subcutaneous injection of 25 mg/kg 7,12-dimethylbenzanthracene (DMBA) in the mammary gland. After sixty days, the rats were randomized into two groups: treated with 200 mg/kg of either açaí extract or vehicle, via gastric tube for 45 consecutive days. The FAC-D protocol was initiated after 90 days of induction by intraperitoneal injection for 3 cycles with a 7-day break each. After treatment, blood was collected for haematological and biochemical analyses, and tumours were collected for macroscopic and histological analyses. In the same way, heart, liver, and kidney samples were also collected for macroscopic and histological analyses.

RESULTS

Breast cancer was found as a cystic mass with a fibrotic pattern in the mammary gland. The histological analysis showed an invasive carcinoma area in both groups; however, in the saline group, there was a higher presence of inflammatory clusters. No difference was observed regarding body weight, glycaemia, aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatinine, and urea in either group. However, açaí treatment decreased creatine kinase (CK), creatine kinase MB (CKMB), troponin I and C-reactive protein levels and increased the number of neutrophils and monocytes. Heart histopathology showed normal myocardium in the açaí treatment, while the saline group presented higher toxicity effects with loss of architecture of cardiac tissue. Furthermore, the açaí treatment presented greater collagen distribution, increased hydroxyproline concentration and lower H2AX immunostaining in the heart samples.

CONCLUSION

Açaí decreased the number of inflammatory cells in the tumor environment and exhibited protection against chemotherapy drug cardiotoxicity with an increased immune response in animals. Thus, açaí can be considered a promising low-cost therapeutic treatment that can be used in association with chemotherapy agents to avoid heart damage.

Characteristics and response to next-generation sequencing-guided therapy in locally advanced or metastatic esophageal cancer

Esophageal cancer (EC) is a main cause of cancer-related deaths. However, genomic alterations and the clinical value of next-generation sequencing (NGS) in advanced or metastatic EC for precision therapy remain largely unclear. Herein, we performed comprehensive analyses on a cohort of 47 individuals with advanced or metastatic EC who underwent NGS between May 2017 and February 2020. Eventually, 227 mutated genes were identified in the cohort. TP53, NQO1, DPYD, GSTM1, XRCC1 and ERCC1 were the most mutated genes and associated with immune cell infiltration, autophagy and hypoxia. Patients who received NGS-guided treatments exhibited better objective remission rate (ORR) (72.22%), disease control rate (DCR) (88.89%), overall survival (OS) (P = .0019) and progression-free survival (PFS) (P = .0077) than those not receiving NGS-guided therapies. The multivariate analyses further demonstrated that the NGS-guided therapy was an independently prognostic factor (OS: hazard radio [HR] 0.31, 95% coincidence interval [CI] 0.1-0.97, P = .04). In conclusion, we depicted a comprehensive mutational landscape of 47 patients with locally advanced or metastatic EC and illustrated the utility of NGS testing to guide clinical management in improving ORR, DCR, OS and PFS.

The Roles of microRNAs in Cancer Multidrug Resistance

Simple Summary

The resistance of neoplastic cells to multiple drugs is a serious problem in cancer chemotherapy. The molecular causes of multidrug resistance in cancer are largely known, but less is known about the mechanisms by which cells deliver phenotypic changes that resist the attack of anticancer drugs. The findings of RNA interference based on microRNAs represented a breakthrough in biology and pointed to the possibility of sensitive and targeted regulation of gene expression at the post-transcriptional level. Such regulation is also involved in the development of multidrug resistance in cancer. The aim of the current paper is to summarize the available knowledge on the role of microRNAs in resistance to multiple cancer drugs.

Abstract

Cancer chemotherapy may induce a multidrug resistance (MDR) phenotype. The development of MDR is based on various molecular causes, of which the following are very common: induction of ABC transporter expression; induction/activation of drug-metabolizing enzymes; alteration of the expression/function of apoptosis-related proteins; changes in cell cycle checkpoints; elevated DNA repair mechanisms. Although these mechanisms of MDR are well described, information on their molecular interaction in overall multidrug resistance is still lacking. MicroRNA (miRNA) expression and subsequent RNA interference are candidates that could be important players in the interplay of MDR mechanisms. The regulation of post-transcriptional processes in the proteosynthetic pathway is considered to be a major function of miRNAs. Due to their complementarity, they are able to bind to target mRNAs, which prevents the mRNAs from interacting effectively with the ribosome, and subsequent degradation of the mRNAs can occur. The aim of this paper is to provide an overview of the possible role of miRNAs in the molecular mechanisms that lead to MDR. The possibility of considering miRNAs as either specific effectors or interesting targets for cancer therapy is also analyzed.

Single nucleotide polymorphisms as the efficient prognostic markers in breast cancer

BACKGROUND

Breast cancer (BC) is known as the most common malignancy in women. Environmental and genetic factors are associated with BC progression. Genetic polymorphisms have been reported as important risk factors of BC prognosis and drug response. Main body: Therefore, in the present review, we have summarized all single nucleotide polymorphisms (SNPs) which have been significantly associated with drug response in BC patients around the world. We have also categorized the reported SNPs based on their related genes functions to clarify the molecular biology of drug responses in BC.

CONCLUSION

The majority of SNPs were reported in detoxifying enzymes, which introduced such genes as the main genetic risk factors during BC drug responses. This review paves the way for introducing a prognostic panel of SNPs for the BC patients in the world.

5-Fluorouracil (5-FU) resistance and the new strategy to enhance the sensitivity against cancer: Implication of DNA repair inhibition

5-Fluorouracil (5-FU) has been an important anti-cancer drug to date. With an increase in the knowledge of its mechanism of action, various treatment modalities have been developed over the past few decades to increase its anti-cancer activity. But drug resistance has greatly affected the clinical use of 5-FU. Overcoming this chemoresistance is a challenge due to the presence of cancer stem cells like cells, cancer recurrence, metastasis, and angiogenesis. In this review, we have systematically discussed the mechanism of 5-FU resistance and advent strategies to increase the sensitivity of 5-FU therapy including resistance reversal. Special emphasis has been given to the cancer stem cells (CSCs) mediated 5-FU chemoresistance and its reversal process by different approaches including the DNA repair inhibition process.

Frequency and Association Of GSTM1 and GSTT1 Gene Polymorphisms with Survival in Breast Cancer Patients

Objective:

Glutathione S-transferase M1 and T1 (GSTM1 and GSTT1) are the key detoxification enzymes of xenobiotics, including chemotherapeutic drugs. The deletion polymorphisms of GSTM1 and GSTT1 genes are associated with reduced enzyme activity that influenced clinical outcomes of chemotherapeutic agents in breast cancer. However, there is limited information among Thai patients. This research aims to explore the frequency and role of GSTM1 and GSTT1 polymorphisms on survival among Thai patients with breast cancer.

Methods:

The retrospective cohort study was performed. Demographic data and clinicopathology characteristics were collected from hospital base registry data and medical records. A multiplex qualitative real-time PCR method was used to detect the presence or absence of the GSTM1 and GSTT1 gene in the genomic DNA samples of the participants.

Results:

The frequencies of the GSTM1 and GSTT1 null genotypes in 198 breast cancer patients were 65.70% and 33.30%, respectively. The overall survival at 1, 3 and 5 years were 95.00%, 83.00%, 71.00% respectively. The log rank test and Cox proportional hazards revealed a significant different in the 5-years overall survival according to lymph node metastasis and tumor stage (P = 0.014 and P < 0.001). No associations between overall survival and GSTM1 or GSTT1 genotype were found in single or combined genotypes analyses (P = 0.76 and P= 0.15).

Conclusion:

The results of our study provided the epidemiological information for prognostic of survival in breast cancer patients treated with chemotherapy.

In vitro Transport Ability of ABCC2 (G1249A) Polymorphic Variant Towards Anticancer Drugs

Objective

Multidrug resistance-associated protein 2 (MRP2), encoded by ABCC2 gene, is involved in the efflux of certain anticancer drugs. Here we observed whether the ABCC2 (G1249A) polymorphism impacts the transport abilities of MRP2-dependent paclitaxel, docetaxel, and doxorubicin in recombinant LLC-PK1 cell lines.

Methods

LLC-PK1 cell lines transfected with ABCC2_1249G wild-type and ABCC2_1249A variant alleles were used to evaluate the sensitivity, intracellular accumulation, and transmembrane transport of paclitaxel, docetaxel, and doxorubicin.

Results

The recombinant ABCC2_1249A variant cell line showed higher IC₅₀ values for paclitaxel and doxorubicin than ABCC2_1249G wild-type cell system (p<0.01). Intracellular accumulations of paclitaxel and doxorubicin in cells transfected with ABCC2_1249A variant allele were significantly decreased compared to cells transfected with ABCC2_1249G wild-type allele (p<0.01). The efflux ratios of paclitaxel and doxorubicin across ABCC2_1249A cell line were significantly increased compared with ABCC2_1249G cell system (p<0.01). However, ABCC2 (G1249A) polymorphism had no effect on the transport activity of MRP2-mediated docetaxel.

Conclusion

Our results indicate that ABCC2 (G1249A) polymorphism affects the transport activities of MRP2-dependent paclitaxel and doxorubicin, resulting in greater efflux of these anticancer drugs.

Breast Cancer Risk-Associated SNPs in the mTOR Promoter Form De Novo KLF5- and ZEB1-Binding Sites that Influence the Cellular Response to Paclitaxel

ZEB1 (a positive enhancer) and KLF5 (a negative silencer) affect transcription factors and play inherently conserved roles in tumorigenesis and multidrug resistance. In humans, the rs2295080T-allele at the mTOR promoter locus has been associated with human cancer risk; however, the 63 bp spacing of another SNP rs2295079 has not been identified. Here, we discovered, for the first time, that rs2295079 (-78C/G) and rs2295080 (-141G/T) formed linkage haplotypes, with Ht1 (-78C/-141G) and Ht2 (-78G/-141T) being dominant, which were associated with distinct susceptibility to breast cancer, response to paclitaxel, and clinical outcomes in breast cancer. At the cellular level, compared with Ht1, Ht2 exhibits a much stronger effect on promoting mTOR expression, leading to enhanced tumor cell growth and strengthened resistance to PTX treatment. Mechanistically, the -141T allele of Ht2 creates a novel ZEB1-binding site; meanwhile, the -78C allele of Ht1 exists as an emerging KLF5-binding site, which synergistically induces promote/inhibit mTOR expression, cell proliferation, and excretion of cytotoxic drugs through the ZEB1/KLF5-mTOR-CCND1/ABCB1 cascade, thereby affecting the response to paclitaxel treatment in vivo and in vitro. Our results suggest the existence of a ZEB1/KLF5-mTOR-CCND1/ABCB1 axis in human cells that could be involved in paclitaxel response pathways and functionally regulate interindividualized breast cancer susceptibility and prognosis. IMPLICATIONS: This study highlights the function of haplotypes of mTOR -78C/-141G and -78G/-141T, in affecting breast cancer susceptibility and paclitaxel response regulated by ZEB1/KLF5-mTOR-CCND1/ABCB1 axis.

Single-nucleotide polymorphisms and mRNA expression of CYP1B1 influence treatment response in triple negative breast cancer patients undergoing chemotherapy

Triple negative breast cancer (TNBC) is typically associated with poor and interindividual variability in treatment response. Cytochrome P450 family 1 subfamily B1 (CYP1B1) is a metabolizing enzyme, involved in the biotransformation of xenobiotics and anticancer drugs. We hypothesized that, single-nucleotide polymorphisms (SNPs), CYP1B1 142 C>G, 4326 C>G and 4360 A>G, and CYP1B1 mRNA expression might be potential biomarkers for prediction of treatment response in TNBC patients. CYP1B1 SNPs genotyping (76 TNBC patients) was performed using allele-specific polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism methods and mRNA expression of CYP1B1 (41 formalin-fixed paraffin embeddedblocks) was quantified using quantitative reverse transcription PCR. Homozygous variant genotype (GG) and variant allele (G) of CYP1B1 4326C>G polymorphism showed significantly higher risk for development of resistance to chemotherapy with adjusted odds ratio (OR): 6.802 and 3.010, respectively. Whereas, CYP1B1 142 CG heterozygous genotype showed significant association with goodtreatment response with adjusted OR: 0.199. CYP1B1 142C-4326G haplotype was associated with higher risk for chemoresistance with OR: 2.579. Expression analysis revealed that the relative expression of CYP1B1 was downregulated (0.592) in cancerous tissue compared with normal adjacent tissues. When analysed for association with chemotherapy response, CYP1B1 expression was found to be significantly upregulated (3.256) in cancerous tissues of patients who did not respond as opposed to those of patients who showed response to chemotherapy. Our findings suggest that SNPs together with mRNA expression of CYP1B1 may be useful biomarkers to predict chemotherapy response in TNBC patients.

Contribution of excision repair cross-complementing group 1 genotypes to triple negative breast cancer risk

Compared with other subgroups of breast cancer, triple negative breast cancer (TNBC) is considered to be the one with the greatest invasiveness and metastatic mobility, and the highest recurrence rate. Considering the lack of predictive markers for TNBC, we aimed to examine the contribution of excision repair cross complementing-group 1 (ERCC1) genotypes to TNBC. The rs11615 and rs3212986 of ERCC1 were investigated and evaluated for their associations with susceptibility to breast cancer, especially TNBC, in Taiwan. In this study, 1,232 breast cancer patients (104 were TNBC) and 1,232 healthy controls were recruited and their genotypes at ERCC1 rs11615 and rs3212986 were revealed by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analysis. Our results indicated that genotypes of ERCC1 rs11615 (Ptrend = 2.2*10E-9), but not rs3212986 (Ptrend = 0.6181), were associated with breast cancer risk. In the allelic frequency distribution analysis, breast cancer patients carried the T allele of ERCC1 rs11615 a higher rate than the control subjects, further supporting the idea that ERCC1 rs11615 TT genotype is positively associated with breast cancer susceptibility. More importantly, the frequency of the ERCC1 rs11615 TT genotype was even higher among TNBC patients than among other subtypes of breast cancer patients (P = 0.0001, odds ratio = 1.73, 95% confidence interval = 1.15-2.63). The genotypes of ERCC1 rs11615 were not associated with Ki67 status. Our findings firstly show that the T allele of ERCC1 rs11615 can serve as a predictive biomarker for breast cancer and TNBC. We believe that ERCC1 could serve as a target for personalized treatment of breast cancer, especially for TNBC.

Knockdown delta-5-desaturase in breast cancer cells that overexpress COX-2 results in inhibition of growth, migration and invasion via a dihomo-γ-linolenic acid peroxidation dependent mechanism

BACKGROUND

Cyclooxygenase-2 (COX-2), the inducible COX form, is a bi-functional membrane-bound enzyme that typically metabolizes arachidonic acid (downstream ω-6 fatty acid) to form 2-series of prostaglandins known to be involved in cancer development. Overexpression of COX-2 has been found in a majority of breast carcinomas, and has also been associated with increased severity and the development of the metastasis. Our lab recently demonstrated that COX-2 can also metabolize dihomo-γ-linolenic acid (DGLA, a precursor of ω-6 arachidonic acid) to produce an anti-cancer byproduct, 8-hydroxyoctanoic acid (8-HOA) that can inhibit growth and migration of colon and pancreatic cancer cells. We thus tested whether our strategy of knocking down delta-5-desaturase (D5D, the key enzyme that converts DGLA to arachidonic acid) in breast cancer cells overexpressing COX-2 can also be used to promote 8-HOA formation, thereby suppressing cancer growth, migration, and invasion.

METHODS

SiRNA and shRNA transfection were used to knock down D5D expression in MDA-MB 231 and 4 T1 cells (human and mouse breast cancer cell lines expressing high COX-2, respectively). Colony formation assay, FITC Annexin V/PI double staining, wound healing and transwell assay were used to assess the effect of our strategy on inhibition of cancer growth, migration, and invasion. GC/MS was used to measure endogenous 8-HOA, and western blotting was performed to evaluate the altered key protein expressions upon the treatments.

RESULTS

We demonstrated that D5D knockdown licenses DGLA to inhibit growth of breast cancer cells via promoting formation of 8-HOA that can inhibit histone deacetylase and activate cell apoptotic proteins, such as procaspase 9 and PARP. Our strategy can also significantly inhibit cancer migration and invasion, associated with altered expression of MMP-2/- 9, E-cadherin, vimentin and snail. In addition, D5D knockdown and DGLA supplementation greatly enhanced the efficacy of 5-fluorouracil on breast cancer growth and migration.

CONCLUSIONS

Consistent to our previous studies on colon and pancreatic cancer, here we demonstrate again that the high level of COX-2 in breast cancer cells can be capitalized on inhibiting cancer growth and migration. The outcome of this translational research could guide us to develop new anti-cancer strategy and/or to improve current chemotherapy for breast cancer treatment.

Pharmacogenetics of toxicity of 5-fluorouracil, doxorubicin and cyclophosphamide chemotherapy in breast cancer patients

The differences in patients' response to the same medication, toxicity included, are one of the major problems in breast cancer treatment. Chemotherapy toxicity makes a significant clinical problem due to decreased quality of life, prolongation of treatment and reinforcement of negative emotions associated with therapy. In this study we evaluated the genetic and clinical risk factors of FAC chemotherapy-related toxicities in the group of 324 breast cancer patients. Selected genes and their polymorphisms were involved in FAC drugs transport (ABCB1, ABCC2, ABCG2,SLC22A16), metabolism (ALDH3A1, CBR1, CYP1B1, CYP2C19, DPYD, GSTM1, GSTP1, GSTT1, MTHFR,TYMS), DNA damage recognition, repair and cell cycle control (ATM, ERCC1, ERCC2, TP53, XRCC1). The multifactorial risk models that combine genetic risk modifiers and clinical characteristics were constructed for 12 toxic symptoms. The majority of toxicities was dependent on the modifications in components of more than one pathway of FAC drugs, while the impact level of clinical factors was comparable to the genetic ones. For the carriers of multiple high risk factors the chance of developing given symptom was significantly elevated which proved the factor-dosage effect. We found the strongest associations between concurrent presence of clinical factors - overall and recurrent anemia, nephrotoxicity and early nausea and genetic polymorphisms in genes responsible for DNA repair, drugs metabolism and transport pathways. These results indicate the possibility of selection of the patients with expected high tolerance to FAC treatment and consequently with high chance of chemotherapy completion without the dose reduction, treatment delays and decline in the quality of life.

Effect of dihydropyrimidine dehydrogenase single nucleotide polymorphisms on prognosis of breast cancer patients with chemotherapy

Defining biomarkers that predict therapeutic effects and adverse events is a crucial mandate to guide patient selection for personalized cancer treatments. DPD (dihydropyrimidine dehydrogenase, encoded by DPYD gene) is the initial and rate-limiting enzyme of metabolic pathway of fluoropyrimidines, and fluoropyrimidines are common used drug therapies for breast cancer. Previous studies on DPYD polymorphism were mainly focused on its association with fluoropyrimidines toxicity. In our present study, 5 DPYD single nucleotide polymorphisms status was detected from tumor tissues of 331 invasive breast cancer patients using standard techniques. We for the first time investigated the prognostic significance of DPYD polymorphisms in breast cancer. We demonstrated non-luminal breast cancer patients carrying DPYD c.1627A>G AG/GG treated with fluoropyrimidine-based regimen presented a shorter overall survival and progression-free survival than carriers treated with non-fluoropyrimidine regimen. However, non-luminal DPYD c.1627A>G AG/GG carriers treated with TE (taxane and anthracycline)-based regimen showed a better prognosis compared with carriers treated with non-TE regimen. Our results suggested TE-based chemotherapy was a suitable regimen for non-luminal patients with DPYD c.1627A>G AG/GG genotype and fluoropyrimidine-based regimen should not be recommended for those patients. Our findings provided a novel strategy, which will guide clinicians to choose more precise chemotherapy treatment for breast cancer patients.

ABCB1 gene polymorphisms and response to chemotherapy in breast cancer patients: A meta-analysis

The ABCB1 gene encodes the P-glycoprotein, an efflux pump for some antineoplastic agents which acts as a resistance mechanism to chemotherapy. Three SNPs (C3435T, C1236T and G2677T/A), are the most widely studied in ABCB1. The inconsistent conclusions about the association of these polymorphisms and the response to chemotherapy in breast cancer (BC) patients prompted us to conduct a meta-analysis. A total of nine (770 patients), five (566 patients) and three studies (367 patients) relating the ABCB1 C3435T, C1236T and G2677T/A polymorphisms respectively, were included. The main analysis revealed a lack of association between ABCB1 polymorphisms and response to chemotherapy in every genetic model: C3435T (dominant OR: 0.888; 95%CI: 0.558-1.413), C1236T (dominant OR: 1.968; 95%CI: 0.609-6.362) and G2677T/A (GG vs GT + GA + TT + TA + AA OR: 0.854; 95%CI: 0.418-1.744). Stratification by ethnicity, cancer type and response criteria did not change the pattern of results. The available evidence indicates that three polymorphisms within ABCB1; C3435T, C1236T and G2677T/A, cannot be considered a reliable predictor of response to chemotherapy in BC patients.