Drug-induced apoptosis and p53, BCL-2 and BAX expression in breast cancer tissues in vivo and in fibroblast cells in vitro

Nanomedicine-induced programmed cell death in cancer therapy: mechanisms and perspectives

The balance of programmed cell death (PCD) mechanisms, including apoptosis, autophagy, necroptosis and others, is pivotal in cancer progression and treatment. Dysregulation of these pathways results in uncontrolled cell growth and resistance to conventional therapies. Nanomedicine offers a promising solution in oncology through targeted drug delivery enabling precise targeting of cancer cells while preserving healthy tissues. This approach reduces the side effects of traditional chemotherapy and enhances treatment efficacy by engaging PCD pathways. We details each PCD pathway, their mechanisms, and innovative nanomedicine strategies to activate these pathways, thereby enhancing therapeutic specificity and minimizing harm to healthy tissues. The precision of nanotechnology in targeting PCD pathways promises significant improvements in cancer treatment outcomes. This synergy between nanotechnology and targeted PCD activation could lead to more effective and less toxic cancer therapies, heralding a new era in cancer treatment.

Estimation of Calcium Titanate or Erbium Oxide Nanoparticles Induced Cytotoxicity and Genotoxicity in Normal HSF Cells

Extensive uses of calcium titanate nanoparticles (CaTiO₃-NPs) and erbium oxide nanoparticles (Er₂O₃-NPs) increase their release into the environment and human exposure, particularly through skin contact. However, there are almost no studies available on the effect of these nanoparticles on skin integrity. Therefore, this study was undertaken to estimate CaTiO₃-NP- or Er₂O₃-NP-induced cytotoxicity and genotoxicity in normal human skin fibroblast (HSF) cells. Cell viability was measured using sulforhodamine B (SRB) assay, while the level of DNA damage was detected using the alkaline comet assay. The intracellular levels of reactive oxygen species (ROS) as well as the expression level of p53, Bax, and Bcl2 genes were detected. Although the viability of HSF cells was non-markedly changed after 24 h, prolonged treatment with CaTiO3-NPs or Er2O3-NPs for 72 h induced concentration-dependent death of HSF cells. Treatment of normal HSF cells with IC50/72 h of CaTiO3-NPs or Er2O3-NPs did not cause marked changes in the intracellular level of ROS, DNA damage parameters, and expression levels of apoptosis genes compared to their values in the untreated HSF cells. We thus concluded that CaTiO3-NPs or Er2O3-NPs cause time- and concentration-dependent cytotoxicity toward normal HSF cells. However, safe and non-genotoxic effects were demonstrated by the apparent non-significant changes in intracellular ROS level, DNA integrity, and apoptotic genes' expression after exposure of normal HSF cells to nanoparticles. Thus, it is recommended that further studies be conducted to further understand the toxic and biological effects of CaTiO₃-NPs and Er2O3-NPs.

Induction of oxidative DNA damage, cell cycle arrest and p53 mediated apoptosis by calcium titanate nanoparticles in MCF-7 breast cancer cells

Background

The distinctive properties and high activity of calcium titanate nanoparticles (CaTiO₃-NPs) increase their use in many products. However, the cytotoxic and genotoxic effects of CaTiO₃-NPs in human cancer cell lines have not been well studied. Therefore, this study was conducted to explore CaTiO₃-NPs induced cytotoxicity, genomic instability and apoptosis in human breast cancer (MCF-7) cells.

Methods

Sulforhodamine B (SRB) and the alkaline comet assays were done to study cell viability and DNA damage induction, respectively. Apoptosis induction and cell cycle distribution were analyzed using flow cytometry. The level of intracellular reactive oxygen species (ROS) was studied, and the expression levels of p53, Bax and Bcl2 genes were also measured.

Results

The results of the Sulforhodamine B (SRB) cytotoxicity assay showed that viability of MCF-7 cells was not affected by CaTiO₃-NPs treatment for 24 h, however, exposure to CaTiO₃-NPs for 72 h caused concentrations dependent death of MCF-7 cells. Treatment with CaTiO₃-NPs for 72 h caused marked increases in intracellular ROS level and induced DNA damage. Treatment of MCF-7 cells with CaTiO₃-NPs also caused MCF-7 cell cycle arrest at the G0 and S phases and s triggered apoptosis of MCF-7 cells by causing simultaneous increases in the expression levels of apoptotic p53 and Bax genes and a decrease in the expression level of anti-apoptotic Bcl2 gene.

Conclusion

Collectively, it was concluded that CaTiO₃-NPs cause time- and concentration-dependent cytotoxic effects in human MCF-7 cells through induction of ROS generation, genomic instability and apoptosis. Thus it is recommended that further in vitro and in vivo studies are therefore recommended to understand the cytotoxic and biological effects of CaTiO₃-NPs.

Induction of ROS mediated genomic instability, apoptosis and G0/G1 cell cycle arrest by erbium oxide nanoparticles in human hepatic Hep-G2 cancer cells

The remarkable physical and chemical characteristics of noble metal nanoparticles, such as high surface-to-volume ratio, broad optical properties, ease of assembly, surfactant and functional chemistry, have increased scientific interest in using erbium oxide nanoparticles (Er₂O₃-NPs) and other noble metal nanostructures in cancer treatment. However, the therapeutic effect of Er₂O₃-NPs on hepatic cancer cells has not been studied. Therefore, the current study was conducted to estimate the therapeutic potential of Er₂O₃-NPs on human hepatocellular carcinoma (Hep-G2) cells. Exposure to Er₂O₃-NPs for 72 h inhibited growth and caused death of Hep-G2 cells in a concentration dependent manner. High DNA damage and extra-production of intracellular reactive oxygen species (ROS) were induced by Er₂O₃-NPs in Hep-G2 cells. As determined by flow cytometry, Er₂O₃-NPs arrested Hep-G2 cell cycle at the G0/G1 phase and markedly increased the number of Hep-G2 cells in the apoptotic and necrotic phases. Moreover, Er₂O₃-NPs caused simultaneous marked increases in expression levels of apoptotic (p53 and Bax) genes and decreased level of anti-apoptotic Bcl2 gene expression level in Hep-G2 cells. Thus it is concluded that Er₂O₃-NPs inhibit proliferation and trigger apoptosis of Hep-G2 cells through the extra ROS generation causing high DNA damage induction and alterations of apoptotic genes. Thus it is recommended that further in vitro and in vivo studies be carried out to study the possibility of using Er2O3-NPs in the treatment of cancer.

Effect of Ducrosia flabellifolia and Savignya parviflora Extracts on Inhibition of Human Colon and Prostate Cancer Cell Lines

The goal of this study was to investigate whether Ducrosia flabellifolia and Savignya parviflora methanol extract the have effect on colon and prostate cancer cell lines. Analysis of total content of phenolics and flavonoids of each plant extract was carried out. Cytotoxic effect, cell cycle analysis, induction of apoptosis and gene expression of Bcl-2 and Bax genes were studied. Obtained results indicated that, the plant extracts exhibit growth inhibition of used cancer cell lines and induced apoptosis as well as arresting of cell cycle. At the molecular level, changes in gene expression were detected via qPCR and confirmed by western blotting. The exhibited anticancer potentialities of plant extracts against utilized cancer cell lines are due to its containing bioactive compounds. Further detailed isolation, fractionation and characterization of bioactive compounds are needed.

Further lead optimization on Bax activators: Design, synthesis and pharmacological evaluation of 2-fluoro-fluorene derivatives for the treatment of breast cancer

To further pursue potent Bax activators with better safety profiles for the treatment of breast cancer, structural optimization was conducted based on lead compound CYD-4-61 through several strategies, including scaffold hopping on the 2-nitro-fluorene ring, replacement of the nitro group with bioisosteres to avoid potential toxicity, and further optimization on the upper pyridine by exploring diverse alkylamine linkers as a tail or replacing the pyridine with bioisosteric heterocycles. F-containing compound 22d (GL0388) exhibited a good balance between the activity and toxicity, displaying submicromolar activities against a variety of cancer cell lines with 5.8-10.7-fold selectivity of decreased activity to MCF-10A human mammary epithelial cell line. Compound 22d dose-dependently blocked colony formation of breast cancer cells and prevented the migration and invasion of MDA-MB-231 cells. Mechanism of action studies indicate that 22d activated Bax, rendering its insertion into mitochondrial membrane, thereby leading to cytochrome c release from the mitochondria into the cytoplasm, subsequently inducing release of apoptotic biomarkers. Further in vivo efficacy studies of 22d in human breast cancer xenografts arisen from MDA-MB-231 cells demonstrated that this drug candidate significantly suppressed tumor growth, indicating the therapeutic promise of this class of compounds for the treatment of breast cancer as well as the potential for developing F-radiolabeled imaging ligands as anticancer chemical probes.

Estimation of mandarin peel oil-induced cytotoxicity and genotoxicity in human normal fibroblast and cancerous prostate cell lines

The low price and high contents of bioactive compounds in citrus peel increase interest in using it in various applications. Mandarin (Citrus reticluata) peel belongs to Rutaceae family and is rich with antioxidants. However, limited studies are available on toxicity of Mandarin peel oil (MPO) on human Prostate Cancer (PC3) cells. Therefore, the present study was conducted to study the cytotoxicity and genotoxicity of MPO on Human normal Fibroblast (HFB4) and PC3 cell lines. The half maximal inhibitory (IC50) and safe concentration of MPO was detected using MTT assay. Comet and DNA fragmentation assays were performed to assess apoptotic DNA damage. Also, the ROS level was evaluated and the mRNA expression level of apoptotic and antiapoptotic genes were measured using RT-PCR. Results of the cytotoxic test showed that MPO induced preferential inhibition of PC3 cells proliferation in a concentration-dependent manner with IC50 10.97 µg/ml. The time-dependent induction of DNA breaks demonstrated in PC3 cells treated with MPO safe concentration-stimulated ROS generation and apoptotic DNA damage through increased expression of tumor suppressor p53 and Bax genes and decreased expression of Bcl2 and MDM2 genes. In contrast, non-significant changes were observed in the DNA integrity, ROS levels and expressions of the tested genes in the normal HFB4 cells treated with MPO. Thus, we concluded that MPO induced preferential cytotoxic and genotoxic effects toward cancerous PC3 with no noticeable toxic effects in normal HFB4 cells and therefore further in vivo studies are recommended to test its possible use as anticancer drugs.

Lung resistance-related protein (LRP) predicts favorable therapeutic outcome in Acute Myeloid Leukemia

There is conflicting evidence that MDR1, MRP2 and LRP expression is responsible for chemotherapy resistance. We conducted this study to explore their role in AML therapy outcomes. Bone marrow and peripheral blood samples of 90 AML patients, receiving chemotherapy, were analyzed by real time PCR. Gene expression was calculated by the 2-ΔΔCt method. The patients who had a persistent remission were labelled 'Good Responder' (GRes) whereas, those with relapse or drug resistance were labelled 'Poor Responders' (PRes). Higher LRP expression in bone marrow, but not in peripheral blood, was positively associated with persistent remission (p = 0.001), GRes (p = 0.002), 1-year overall as well as disease-free survival (p = 0.02 and p = 0.007, respectively). Marrow and blood MDR1 and MRP2 expression did not differ significantly between the above groups. Logistic regression analysis showed that only a diagnosis of acute promyelocytic leukemia (APL; M3) or high marrow LRP expression significantly predicted a favorable therapeutic outcome. This is the first report showing that high bone marrow LRP expression predicts significant favorable therapeutic outcome. Peripheral blood LRP expression as well as marrow and blood MDR1 and MRP2 expression have no predictive value in AML patients treated with standard dose cytarabine and daunorubicin 3+7 regimen.

Gene expression of hENT1, dCK, CDA, dCMPD and topoisomerase IIα as an indicator of chemotherapy response in AML treated with cytarabine and daunorubicin

Purpose

Acute myeloid leukemia patients are commonly treated with cytarabine (Ara-C) and anthracyclines but the sustained remission rate is not very promising. We explored the role of drug-metabolizing enzymes and transporters in the therapeutic response.

Patients and methods

Bone marrow and peripheral blood samples of 90 newly diagnosed acute myeloid leukemia patients treated with standard 3+7 regimen were analyzed through real-time PCR for expression of human equilibrative nucleoside transporter 1, deoxycytidine kinase, cytidine deaminase (CDA), deoxycytidine monophosphate deaminase (dCMPD) and topoisomerase IIα (Topo-IIa). The expression of these markers was studied in relationship with good (persistent remission) and poor therapeutic response (relapse/resistance).

Results

High Topo-IIa expression in peripheral blood was associated with good response (P=0.006). Relapse was higher among low expressors of Topo-IIa in peripheral blood (OR: 26.25). Bone marrow Topo-IIa expression followed a similar trend but did not reach statistical significance. In contrast, patients with high bone marrow dCMPD expression had poor response (OR: 3; P=0.043). One-year disease-free survival (DFS) was better among those with high bone marrow Topo-IIa (P=0.04) or CDA (P=0.03) expression. High bone marrow Topo-IIa expression also had better DFS at 6 months (P=0.04) and at 12 months (P=0.04).

Conclusion

High expression of Topo-IIa in peripheral blood is a favorable indicator of persistent remission, good therapeutic response and DFS. High dCMPD and low CDA expression in bone marrow is associated with poor therapeutic outcome.

Bax, Bcl-2, and Bax/Bcl-2 as prognostic markers in acute myeloid leukemia: are we ready for Bcl-2-directed therapy?

Purpose

Many anticancer drugs induce apoptosis in malignant cells, and resistance to apoptosis could lead to suboptimal or no therapeutic benefit. Two cytoplasmic proteins, B-cell lymphoma protein 2 (Bcl-2)-associated X (Bax) and Bcl-2, act as a promoter and an inhibitor of apoptosis, respectively. Both Bax and Bcl-2 as well as their ratio have been regarded as prognostic markers in various cancers. However, conflicting results have been reported. A clear understanding of apoptosis has also become crucial due to reports about anti-Bcl-2 chemotherapy. We explored the relationship of Bax and Bcl-2 gene expression and their ratio with the therapeutic response in acute myeloid leukemia (AML) patients.

Patients and methods

Bone marrow and/or blood samples from 90 AML patients treated with cytarabine and daunorubicin were included. Expression of Bax and Bcl-2 was determined through real-time polymerase chain reaction by using ΔΔCt method of relative expression.

Results

Bax and Bcl-2 expression among marrow and blood samples correlated with each other (r_s=0.5, p<0.01). Although bone marrow expression of Bax and Bcl-2 tended to remain higher among responders (median 1.01 and 0.29, respectively) as compared to non-responders (median 0.66 and 0.24, respectively), the difference failed to reach statistical significance (U=784.5 and 733; p=0.68 and 0.28, respectively). Conversely, Bax/Bcl-2 ratio was higher among poor responders (median 3.07 vs 1.78), though again failed to reach statistical significance (U=698.5, p=0.07).

Conclusion

Expression of Bax and Bcl-2 does not differ significantly among AML patients treated with cytarabine and daunorubicin in terms of remission, relapse, resistance, overall survival, and disease-free survival, thus questioning the utility of emerging anti-Bcl-2 therapy.

Somatostatin receptor expression on von Hippel-Lindau-associated hemangioblastomas offers novel therapeutic target

Von Hippel-Lindau (VHL)-associated hemangioblastomas (VHL-HB) arise in the central nervous system (CNS), and are a leading cause of morbidity and mortality in VHL disease. Currently, surgical resection is the most effective way to manage symptomatic VHL-HBs. Surgically unresectable VHL-HBs or those in frail patients are challenging problems. Therapies targeting oncologic and vascular endothelial growth factor (VEGF) pathways have failed to demonstrate tumor control. Our experience and previous reports on VHL-HB avidity to somatostatin analogues suggested somatostatin receptor (SSTR) expression in VHL-HBs, offering an alternative therapeutic strategy. We explored this possibility by demonstrating consistent histologic expression of SSTR1, 2a, 4, and 5 in VHL-HBs. We found that somatostatin analogue octreotide induces apoptosis in VHL-HB stromal cells in a dose-dependent fashion by BAX – caspase-3 pathway unrelated to canonical VHL pathway. When administered to a patient with unresectable symptomatic suprasellar hemangioblastoma, octreotide resulted in tumor volume reduction, symptom stabilization, and tumor cytopenia on repeat ⁶⁸Ga-DOTA-TATE positron emission tomography (PET) within 6 months, suggesting tumor infarction. We conclude that VHL-HBs harbor multiple SSTR subtypes that offer actionable chemo-therapeutic strategy for management of symptomatic, unresectable tumors by somatostatin analogue therapy.

Evaluation of in vitro anticancer activity of Ocimum basilicum, Alhagi maurorum, Calendula officinalis and their parasite Cuscuta campestris

The present investigation was carried out to study the relationship between presence of cytotoxic compounds in Ocimum basilicum, Alhagi maurorum, Calendula officinalis and their parasite Cuscuta campestris. The cytotoxic activity of the pure compounds was performed by MTT assay against breast cancer cell lines (MCF-7 and MDA-MB-231) and normal breast cell line (MCF 10A). The induction of apoptosis was measured by the expression levels of p53, bcl-2, bax and caspase-3 genes using quantitative Real Time PCR. Three active fractions were detected by nuclear magnetic resonance as lutein, lupeol and eugenol, respectively, in C. officinalis, A. maurorum and O. basilicum. These compounds and their epoxidized forms were also detected in their parasite C. campestris. The cytotoxic activity of lutein epoxide, lupeol epoxide and eugenol epoxide was significantly more than lutein, lupeol and eugenol. The mRNA expression level of p53, caspase-3 and bax genes were increased in both cancer cells treated with all pure compounds. However, bcl-2 gene expression decreased in treated breast cancer cells. In conclusion, all the data indicated that the epoxide forms of lupeol, lutein and eugenol are potential drug candidates for inducing apoptosis in human breast cancer cells.

SFRP2 and slug contribute to cellular resistance to apoptosis in hypertrophic scars

Hypertrophic scars (HS) are skin disorders which occur after wounding and thermal injury. Our previous studies have suggested that secreted frizzled-related protein 2 (SFRP2) is involved in HS formation and that the suppression of SFRP2 promotes apoptosis of hypertrophic scar fibroblasts (HSFBs). However, the mechanisms have not been clarified. Previous studies revealed that Slug expression inhibits cell apoptosis, in vitro and in vivo, and SFRP2 regulates the expression of Slug in cervical cancer cells. In the present study, we quantified differential expression levels of expression of SFRP2 and Slug in HS and normal skin tissues by immunohistochemistry, both of which have important anti-apoptosis roles. Furthermore, a short hairpin RNA approach was adopted to investigate the potential function of SFRP2 and Slug in HSFB apoptosis. Cell apoptosis was detected using fluorescence-activated cell sorting and Caspase-3 activity was assayed by spectrophotometry. This study demonstrates that SFRP2 expression, as well as Slug, is dramatically up-regulated in HS relative to normal skin tissues, and the Slug expression is positively correlated with SFRP2. Slug expression was down-regulated in SFRP2-deficient cells, and the down-regulation of Slug expression increased sensitivity to apoptosis which was induced through a caspase-3-dependent pathway. The infected cells with reduced levels of Slug were tested for the expression of apoptosis-related genes (Bcl-2, Bax and PUMA) which were previously identified as Slug targets. Bcl-2 expression was down-regulated in Slug-deficient cells. In conclusion, SFRP2 appears to interact with Slug to affect the apoptosis of hypertrophic scar fibroblasts.

Clinical Significance of p53 and bcl-2 Protein Coexpression Phenotypes in Molecular Breast Cancer Subtypes of Pre-menopausal and Post-menopausal African-American Women

With the current classification of breast carcinoma into molecular subtypes with distinct prognosis and response to therapy, we sort to assess the clinical significance of p53 and bcl-2 coexpression phenotypes in invasive breast tumors and correlate this to the different molecular breast cancer subtypes in African-American women. We performed a retrospective analysis of data on p53 and bcl-2 expression. Results were correlated to molecular breast cancer subtypes, and clinicopathologic variables of prognostic significance. Our study sample included all African-American women diagnosed with breast cancer from 1998 to 2005. Twenty-seven (27.6%) per cent of cases in our study sample over-expressed p53, whereas 69.3 per cent over-expressed bcl-2 protein. A significant inverse correlation was observed between expression of p53 and bcl-2. Combined analysis of p53 and bcl-2 showed that 53.2 per cent of the tumors displayed p53(-)bcl-2(+) phenotype which was significantly associated with the luminal A subtype, whereas 11.6 per cent displayed the p53(+)bcl-2(-) phenotype which was significantly associated with the basal cell-like and Her-2/neu. Neither p53 expression nor bcl-2 expression individually or in combination were of independent prognostic significance. p53(+)bcl-2(-) phenotype is significantly correlated with the basal cell-like subtype and may be associated with the biologic aggressiveness of this cohort of molecular breast cancer.

Transcriptional down-regulation of Bcl-2 by vinorelbine: identification of a novel binding site of p53 on Bcl-2 promoter

The Bcl-2 family contains a panel of proteins which are conserved regulators of apoptosis in mammalian cells, like the anti-apoptotic protein Bcl-2. According to its significant role in altering susceptibility to apoptosis, the deciphering of the mechanism of Bcl-2 expression modulation may be crucial for identifying therapeutics strategies for cancer. Treatment with microtubule-targeting agents, including taxanes and Vinca alkaloids, generally leads to a decrease in Bcl-2 intracellular amounts. Whereas the interest for these chemotherapeutics is accompanied by advances in the fundamental understanding of their anticancer properties, the molecular mechanism underlying changes in Bcl2 expression remains poorly understood. We report here that p53 contributes to vinorelbine-induced Bcl-2 down-regulation. Indeed, the decrease in Bcl-2 protein levels observed during vinorelbine-induced apoptosis was correlated to the decrease in mRNA levels, as a result of the inhibition of Bcl-2 transcription and promoter activity. In this context, we evaluated p53 contribution in the Bcl-2 transcriptional down-regulation. We identified, by chromatin immunoprecipitation, a novel p53 binding site in the Bcl-2 promoter, within a region upstream P(1) promoter. We showed that vinorelbine treatment increased this interaction in A549 cells. This work strengthens the links between p53 and Bcl-2 at a transcriptional level, upon microtubule-targeting agent treatment. Our study also provides answers that will be useful to assess microtubule-targeting agents' mechanism of action and that may help to better understand and increase their effectiveness.

Gene expression profiling revealed novel mechanism of action of Taxotere and Furtulon in prostate cancer cells

Background

Both Taxotere and Capecitabine have shown anti-cancer activity against various cancers including prostate cancer. In combination, Taxotere plus Capecitabine has demonstrated higher anti-cancer activity in advanced breast cancers. However, the molecular mechanisms of action of Taxotere and Capecitabine have not been fully elucidated in prostate cancer.

Methods

The total RNA from PC3 and LNCaP prostate cells untreated and treated with 2 nM Taxotere, 110 μM Furtulon (active metabolite of Capecitabine), or 1 nM Taxotere plus 50 μM Furtulon for 6, 36, and 72 hours, was subjected to Affymetrix Human Genome U133A Array analysis. Real-time PCR and Western Blot analysis were conducted to confirm microarray data.

Results

Taxotere and Furtulon down-regulated some genes critical for cell proliferation, cell cycle progression, transcription factor, cell signaling, and oncogenesis, and up-regulated some genes related to the induction of apoptosis, cell cycle arrest, and differentiation in both cell lines. Taxotere and Furtulon also up-regulated some genes responsible for chemotherapeutic resistance, suggesting the induction of cancer cell resistance to these agents.

Conclusions

Taxotere and Furtulon caused the alternation of a large number of genes, many of which may contribute to the molecular mechanisms by which Taxotere and Furtulon inhibit the growth of prostate cancer cells. This information could be utilized for further mechanistic research and for devising optimized therapeutic strategies against prostate cancer.

Capecitabine Plus Paclitaxel As Front-Line Combination Therapy for Metastatic Breast Cancer: A Multicenter Phase II Study

Purpose

The goal of this multicenter, open-label phase II study was the clinical evaluation of combination therapy with the oral fluoropyrimidine capecitabine and the taxane paclitaxel in patients with metastatic breast cancer (MBC).

Patients and Methods

Forty-seven patients with MBC received oral capecitabine at 1,650 mg/m2/d (825 mg/m2 twice daily) on days 1 through 14, and intravenous infusion of paclitaxel at 175 mg/m2 on day 1 of each 21-day treatment cycle. Treatment continued until disease progression, intolerable toxicity, or patient's decision to discontinue. Patients (35 to 76 years old) had a median Karnofsky performance status of 90%. Forty-four patients (94%) received study treatment as first-line therapy for metastatic disease.

Results

Objective responses occurred in 24 (51%) patients; seven (15%) complete responses and 17 (36%) partial responses. Stable disease lasting 180 days or more was observed in nine (19%); the clinical response rate was 70%. Median duration of response was 12.6 months, median time to disease progression was 10.6 months, and median overall survival time was 29.9 months. The most common treatment-related adverse events, regardless of severity, were alopecia, hand-foot syndrome, nausea, and fatigue. Neutropenia (15%), alopecia (13%), and hand-foot syndrome (11%) were the only grade 3 or 4 treatment-related adverse events that occurred in more than 10% of patients.

Conclusion

The combination of capecitabine plus paclitaxel is a highly active and generally well-tolerated regimen for first-line treatment of MBC.

P53 and breast cancer

p53 mutation is the most common genetic abnormality found so far in human cancer, and in breast cancer p53 mutation/alteration is seen in up to 50% of primary carcinomas. Together with the increasing knowledge of the characteristics and understanding of the role of p53 over the last two decades, attention in recent years has been focused on how this knowledge can be used in clinical settings for patient care and management in terms of analyzing p53 as a potential marker for studying the relationship between p53 expression and tumour development, progression and outcome; and designing alternative treatment strategies specifically aimed at restoring normal p53 function.