Novel Strategies Using Sagacious Targeting for Site-Specific Drug Delivery in Breast Cancer Treatment: Clinical Potential and Applications

For more than a decade, researchers have been working to achieve new strategies and smart targeting drug delivery techniques and technologies to treat breast cancer (BC). Nanotechnology presents a hopeful strategy for targeted drug delivery into the building of new therapeutics using the properties of nanomaterials. Nanoparticles are of high regard in the field of diagnosis and the treatment of cancer. The use of these nanoparticles as an encouraging approach in the treatment of various cancers has drawn the interest of researchers in recent years. In order to achieve the maximum therapeutic effectiveness in the treatment of BC, combination therapy has also been adopted, leading to minimal side effects and thus an enhancement in the quality of life for patients. This review article compares, discusses and criticizes the approaches to treat BC using novel design strategies and smart targeting of site-specific drug delivery systems.

Cancer-biomarkers associated with sex hormone receptors and recent therapeutic advancements: a comprehensive review

Hormones and its regulation plays vital role in causing breast, prostate, ovarian and endometrial cancers collectively known as hormone-sensitive cancers. This review discusses the various functions of the sex hormones and the biological pathways involved in causing hormone-associated cancer under differential regulation. We have also attempted to explore the biomarkers associated with the cancers and the current therapeutic availability to treat such cancers. Among various sex hormones such as estrogen, progesterone and androgen, estrogen the female sex hormone and its receptor had a major contribution in causing cancer and hence are considered a predominant target in treating the associated cancers. Other hormones and receptors such a androgen, progesterone, and their respective receptors were also reported to have a significant correlation in causing cancers. Apart from these receptors certain enzymes that act as precursors or as promoters are also targeted for treatment strategies. The drugs commonly used belong to the selective drug classes such as selective estrogen receptor modulators and selective progesterone receptor modulators. In the case of androgen regulation androgen deprivation therapies are practiced. It is also suggested that the use of natural substances to treat cancer could prevent resistance and reduce side effects. Identification of significant targets and the discovery of many efficient drugs shall be possible in the future with better understanding of hormone regulation and its influence on cancer causative mechanisms.

Prolactin receptor gene transcriptional control, regulatory modalities relevant to breast cancer resistance and invasiveness

The prolactin receptor (PRLR) is a member of the lactogen/cytokine receptor family, which mediates multiple actions of prolactin (PRL). PRL is a major hormone in the proliferation/differentiation of breast epithelium that is essential for lactation. It is also involved in breast cancer development, tumor growth and chemoresistance. Human PRLR expression is controlled at the transcriptional level by multiple promoters. Each promoter directs transcription/expression of a specific non-coding exon 1, a common non-coding exon 2 and coding exons E3-11. The identification of exon 11 of PRLR led to finding of alternative spliced products and two novel short forms (SF) that can inhibit the long form (LF) of PRLR activity with relevance in physiological regulation and breast cancer. Homo and heterodimers of LF and SF are formed in the absence of PRL that acts as a conformational modifier. Heterodimerization of SF with LF is a major mechanism through which SF inhibits some signaling pathways originating at the LF. Biochemical/molecular modeling approaches demonstrated that the human PRLR conformation stabilized by extracellular intramolecular S-S bonds and several amino acids in the extracellular D1 domain of PRLR SF are required for its inhibitory actions on PRLR LF-mediated functions. Studies in breast cancer cells demonstrated that the transcription of PRLR was directed by the preferentially utilized PIII promoter, which lacks an estrogen responsive element. Complex formation of non-DNA bound ERα dimer with Sp1 and C/EBPβ dimers bound to their sites at the PRLR promoter is required for basal activity. Estradiol induces transcriptional activation/expression of the PRLR gene, and subsequent studies revealed the essential role of autocrine PRL released by breast cancer cells and CDK7 in estradiol-induced PRLR promoter activation and upregulation. Other studies revealed stimulation of the PRLR promoter activity and PRLR LF protein by PRL in the absence of estrogen via the STAT5/phospho-ERα activation loop. Additionally, EGF/ERBB1 can induce the transcription of PRLR independent of estrogen and prolactin. The various regulatory modalities contributing to the upregulation of PRLR provide options for the development of therapeutic approaches to mitigate its participation in breast cancer progression and resistance.

Crosstalk between PRLR and EGFR/HER2 Signaling Pathways in Breast Cancer

Prolactin receptor (PRLR) and epidermal growth factor receptor (EGFR/ERBB) signaling pathways activated by prolactin (PRL) and epidermal growth factor (EGF), have a major role in the mammary gland development and in the etiology of breast cancer, respectively. ER+ breast tumors comprise up to 75% of all breast cancers and 10% of these are HER2+. Elevated levels of PRLR in breast tumors, high circulating levels of PRL and increased expression of ERBB1/2 in patients that become resistant to endocrine therapy have shown to be associated with higher risk of cancer progression. In this review, we examine the role of crosstalk between PRLR and ERBB1/2 signaling pathways in the activation of unliganded ERα, cyclin-D1 and other oncogenic factors (MYC, FOS, JUN) in breast cancer. PRL/PRLR and EGF/EGFR induces phosphorylation of ERα through activation of MEK/MAPK and PI3K/AKT signaling pathways. PRL in breast cancer cells via PRLR/JAK2 can also induce phosphorylation of ERBB2/HER2, which in turn activates the downstream RAS/MEK/ERK pathway required for ERα phosphorylation. EGFR, independent of PRL/PRLR, can activate STAT5 indirectly via c-SRC and drive the expression of target genes involved in cell proliferation and survival. The crosstalk between PRLR and HER2, where PRL induces HER2 signaling can be an alternative route for ERα activation to induce transcription of PRLR and other ER target genes. We believe that overexpression of EGFR/HER2 and PRLR in breast tumors could maximize the actions of their ligands, and further induce cell proliferation promoting malignancy. This could also explain the resistance to endocrine therapy resulting in tumor growth.

Multimodal Decorations of Mesoporous Silica Nanoparticles for Improved Cancer Therapy

The presence of leaky vasculature and the lack of lymphatic drainage of small structures by the solid tumors formulate nanoparticles as promising delivery vehicles in cancer therapy. In particular, among various nanoparticles, the mesoporous silica nanoparticles (MSN) exhibit numerous outstanding features, including mechanical thermal and chemical stability, huge surface area and ordered porous interior to store different anti-cancer therapeutics with high loading capacity and tunable release mechanisms. Furthermore, one can easily decorate the surface of MSN by attaching ligands for active targeting specifically to the cancer region exploiting overexpressed receptors. The controlled release of drugs to the disease site without any leakage to healthy tissues can be achieved by employing environment responsive gatekeepers for the end-capping of MSN. To achieve precise cancer chemotherapy, the most desired delivery system should possess high loading efficiency, site-specificity and capacity of controlled release. In this review we will focus on multimodal decorations of MSN, which is the most demanding ongoing approach related to MSN application in cancer therapy. Herein, we will report about the recently tried efforts for multimodal modifications of MSN, exploiting both the active targeting and stimuli responsive behavior simultaneously, along with individual targeted delivery and stimuli responsive cancer therapy using MSN.

Correlation between a variable number tandem repeat (VNTR) polymorphism in SMYD3 gene and breast cancer: A genotype-phenotype study

Genetic predisposition to breast cancer (BC) has become one of the most studied aspects of the disease. Advances in the field of cancer research have revealed the role of different genetic polymorphisms within genes of interest in the development of BC. This study aimed to explore the impact of a variable number tandem repeat (VNTR) genetic variant found within the SET and MYND domain containing protein 3 (SMYD3) gene on BC risk in Jordan and examine key clinical and pathological prognostic factors. Genotyping of blood samples from 180 cases with breast cancer and 180 healthy individuals from the Jordanian population was carried out via a combination of PCR and agarose gel electrophoresis. A highly significant association was found at level of genotype (P-value = 0.009) and allele (P-value = 0.0001) between BC development and the VNTR variant in the SMYD3 gene among Jordanian women. Moreover, we found that the VNTR of SMYD3 gene may interfere with BC risk among patients with different immunohistochemistry (IHC) profiles (P-value < 0.05). This study reported that there is a significant correlation between BC development and the VNTR in the SMYD3 gene. These findings can help alleviate the burden of BC in developing countries including Jordan and to fill the gaps in current literature. Since this study was carried out on Jordanian Arabs, more studies on the link between BC and the SMYD3 VNTR variant are recommended to determine this polymorphism's impact on other ethnic groups.

The evolving role of receptors as predictive biomarkers for metastatic breast cancer

INTRODUCTION

In breast cancer, estrogen receptor (ER) and human epidermal growth factor receptor 2 (HER2) are essential biomarkers to predict response to endocrine and anti-HER2 therapies, respectively. In metastatic breast cancer, the use of these receptors and targeted therapies present additional challenges: temporal heterogeneity, together with limited sampling methodologies, hinders receptor status assessment, and the constant evolution of the disease invariably leads to resistance to treatment. Areas covered: This review summarizes the genomic abnormalities in ER and HER2, such as mutations, amplifications, translocations, and alternative splicing, emerging as novel biomarkers that provide an insight into underlying mechanisms of resistance and hold potential predictive value to inform treatment selection. We also describe how liquid biopsies for sampling of circulating markers and ultrasensitive detection technologies have emerged which complement ongoing efforts for biomarker discovery and analysis. Expert commentary: While evidence suggests that genomic aberrations in ER and HER2 could contribute to meeting the pressing need for better predictive biomarkers, efforts need to be made to standardize assessment methods and better understand the resistance mechanisms these markers denote. Taking advantage of emerging technologies, research in upcoming years should include prospective trials incorporating these predictors into the study design to validate their potential clinical value.

Metastatic and triple-negative breast cancer: challenges and treatment options

The major current conventional types of metastatic breast cancer (MBC) treatments include surgery, radiation, hormonal therapy, chemotherapy, or immunotherapy. Introducing biological drugs, targeted treatment and gene therapy can potentially reduce the mortality and improve the quality of life in patients with MBC. However, combination of several types of treatment is usually recommended. Triple negative breast cancer (TNBC) accounts for 10-20% of all cases of breast carcinoma and is characterized by the low expression of progesterone receptor (PR), estrogen receptor (ER), and human epidermal growth factor receptor 2 (HER2). Consequently, convenient treatments used for MBC that target these receptors are not effective for TNBC which therefore requires special treatment approaches. This review discusses the occurrence of MBC, the prognosis and predictive biomarkers of MBC, and focuses on the novel advanced tactics for treatment of MBC and TNBC. Nanotechnology-based combinatorial approach for the suppression of EGFR by siRNA and gifitinib is described.

Correlations of EZH2 and SMYD3 gene polymorphisms with breast cancer susceptibility and prognosis

The aim of the present study was to investigate the correlation of enhancer of Zeste homolog 2 (EZH2) and SET and MYND domain containing 3 (SMYD3) gene polymorphisms with breast cancer susceptibility and prognosis. A total of 712 patients with breast cancer and 783 healthy individuals were selected. Normal breast epithelial cells MCF-10A and breast cancer cells MCF-7, MDA-MB-231, T47D, and Bcap-37 were cultured. Polymerase chain reaction (PCR)-restriction fragment length polymorphism method was applied for genotyping. Reverse-transcription quantitative PCR (RT-qPCR) and Western blotting were used to examine EZH2 and SMYD3 expression in breast cancer tissues and cells. The risk factors and prognostic factors for breast cancer were estimated. The C allele of EZH2 rs12670401 (odds ratio (OR) =1.255, 95% confidence interval (95% CI): 1.085-1.452), T allele of EZH2 rs6464926 (OR =1.240, 95% CI: 1.071-1.435), and three alleles of SMYD3 variable number of tandem repeats (VNTRs) (OR =1.305, 95% CI: 1.097-1.552) could increase susceptibility to breast cancer. Combined genotypes of EZH2 rs12670401 (TC + CC) and EZH2 rs6464926 (CT + TT) were associated with breast cancer susceptibility. Breast cancer tissues had higher EZH2 and SMYD3 expression. EZH2 rs12670401, EZH2 rs6464926, age of menarche, and menopausal status were associated with breast cancer susceptibility. Patients with TT genotype of EZH2 rs12670401 or with CC genotype of EZH2 rs6464926 had higher overall survival (OS). EZH2 rs12670401, EZH2 rs6464926, and clinical staging were independent prognostic factors for breast cancer. SMYD3 VNTR polymorphism exhibited no association with susceptibility and prognosis. EZH2 rs12670401 and rs6464926 polymorphisms, EZH2 and SMYD3 expression, clinical staging, lymph node metastasis, human epidermal growth factor receptor-2 (HER2) status, and metastasis may be correlated with breast cancer susceptibility and prognosis.

Molecular Mechanisms and Translational Therapies for Human Epidermal Receptor 2 Positive Breast Cancer

Breast cancer is the second leading cause of cancer death among women. Human epidermal receptor 2 (HER2) positive breast cancer (HER2+ BC) is the most aggressive subtype of breast cancer, with poor prognosis and a high rate of recurrence. About one third of breast cancer is HER2+ BC with significantly high expression level of HER2 protein compared to other subtypes. Therefore, HER2 is an important biomarker and an ideal target for developing therapeutic strategies for the treatment HER2+ BC. In this review, HER2 structure and physiological and pathological roles in HER2+ BC are discussed. Two diagnostic tests, immunohistochemistry (IHC) and fluorescent in situ hybridization (FISH), for evaluating HER2 expression levels are briefly introduced. The current mainstay targeted therapies for HER2+ BC include monoclonal antibodies, small molecule tyrosine kinase inhibitors, antibody-drug conjugates (ADC) and other emerging anti-HER2 agents. In clinical practice, combination therapies are commonly adopted in order to achieve synergistic drug response. This review will help to better understand the molecular mechanism of HER2+ BC and further facilitate the development of more effective therapeutic strategies against HER2+ BC.

A common promoter hypomethylation signature in invasive breast, liver and prostate cancer cell lines reveals novel targets involved in cancer invasiveness

Cancer invasion and metastasis is the most morbid aspect of cancer and is governed by different cellular mechanisms than those driving the deregulated growth of tumors. We addressed here the question of whether a common DNA methylation signature of invasion exists in cancer cells from different origins that differentiates invasive from non-invasive cells. We identified a common DNA methylation signature consisting of hyper- and hypomethylation and determined the overlap of differences in DNA methylation with differences in mRNA expression using expression array analyses. A pathway analysis reveals that the hypomethylation signature includes some of the major pathways that were previously implicated in cancer migration and invasion such as TGF beta and ERBB2 triggered pathways. The relevance of these hypomethylation events in human tumors was validated by identification of the signature in several publicly available databases of human tumor transcriptomes. We shortlisted novel invasion promoting candidates and tested the role of four genes in cellular invasiveness from the list C11orf68, G0S2, SHISA2 and TMEM156 in invasiveness using siRNA depletion. Importantly these genes are upregulated in human cancer specimens as determined by immunostaining of human normal and cancer breast, liver and prostate tissue arrays. Since these genes are activated in cancer they constitute a group of targets for specific pharmacological inhibitors of cancer invasiveness.

Implementation of CE-MS-identified proteome-based biomarker panels in drug development and patient management

The recent advancements in clinical proteomics enabled identification of biomarker panels for a large range of diseases. A number of CE-MS-identified biomarker panels were verified and implemented in clinical studies. Despite multiple challenges, accumulating evidence supports the value and the need for proteome-based biomarker panels. In this perspective, we provide an overview of clinical studies indicating the added value of CE-MS biomarker panels over traditional diagnostics and monitoring methods. We outline apparent advantages of applying novel proteomic biomarker panels for disease diagnosis, prognosis, staging, drug development and patient management. Facing the plethora of benefits associated with the use of CE-MS biomarker panels, we envision their implementation into the medical practice in the near future.

A novel gene-protein assay for evaluating HER2 status in gastric cancer: simultaneous analyses of HER2 protein overexpression and gene amplification reveal intratumoral heterogeneity

BACKGROUND

Human epidermal growth factor receptor 2 (HER2) protein overexpression and gene amplification are important biomarkers for trastuzumab treatment in breast and gastric cancer patients. Gastric cancer presents high rates of tumor heterogeneity, which may influence the results of HER2 testing. A novel gene-protein assay (GPA) can allow the simultaneous analysis of HER2 protein and gene status on a single slide.

METHODS

Using the tissue microarray technique, the HER2 status of each of 875 gastric cancer cases was evaluated by immunohistochemistry (IHC), brightfield dual-color in situ hybridization (DISH), and GPA. Intratumoral phenotypic and genotypic heterogeneity were evaluated by comparing the HER2 statuses of two tissue cores from each case.

RESULTS

There was excellent concordance between GPA and IHC (99.2 %), as well as between GPA and DISH results (99.3 %). HER2 positivity obtained by GPA was almost identical (99.8 %) to the results obtained by IHC and DISH assays. Intratumoral phenotypic heterogeneity was more frequently observed in IHC 2+ cases (63.5 %) compared with IHC 3+ cases (28.3 %). Phenotypic heterogeneity (48.8 %) was more frequently observed than genotypic heterogeneity (26.8 %). Tumor heterogeneity was consistently observed from early to advanced stages.

CONCLUSIONS

HER2-positive gastric cancers presented different levels of HER2 protein expression and gene amplification statuses within the same lesion in almost half the cases examined. Evaluating both phenotypic and genotypic heterogeneity may contribute to a deeper understanding and improved prediction of clinical outcome in gastric cancer patients treated with trastuzumab. This newly established GPA technology may also be useful for developing biomarkers for other molecularly targeted therapies.

Anti-epidermal growth factor receptor conjugated mesoporous zinc oxide nanofibers for breast cancer diagnostics

We report the fabrication of an efficient, label-free, selective and highly reproducible immunosensor with unprecedented sensitivity (femto-molar) to detect a breast cancer biomarker for early diagnostics. Mesoporous zinc oxide nanofibers (ZnOnFs) are synthesized by electrospinning technique with a fiber diameter in the range of 50-150 nm. Fragments of ZnOnFs are electrophoretically deposited on an indium tin oxide glass substrate and conjugated via covalent or electrostatic interactions with a biomarker (anti-ErbB2; epidermal growth factor receptor 2). Oxygen plasma treatment of the carbon doped ZnOnFs generates functional groups (-COOH, -OH, etc.) that are effective for the conjugation of anti-ErbB2. ZnOnFs without plasma treatment that conjugate via electrostatic interactions were also tested for comparison. Label-free detection of the breast cancer biomarker by this point-of-care device is achieved by an electrochemical impedance technique that has high sensitivity (7.76 kΩ μM(-1)) and can detect 1 fM (4.34 × 10(-5) ng mL(-1)) concentration. The excellent impedimetric response of this immunosensor provides a fast detection (128 s) in a wide detection test range (1.0 fM-0.5 μM). The oxy-plasma treated ZnOnF immunoelectrode shows a higher association constant (404.8 kM(-1) s(-1)) indicating a higher affinity towards the ErbB2 antigen compared to the untreated ZnOnF immunoelectrode (165.6 kM(-1) s(-1)). This sensor is about an order of magnitude more sensitive than the best demonstrated in the literature based on different nanomaterials and about three orders of magnitude better than the ELISA standard for breast cancer biomarker detection. This proposed point-of-care cancer diagnostic offers several advantages, such as higher stability, rapid monitoring, simplicity, cost-effectiveness, etc., and should prove to be useful for the detection of other bio- and cancer markers.

Homologous Mutation to Human BRAF V600E Is Common in Naturally Occurring Canine Bladder Cancer--Evidence for a Relevant Model System and Urine-Based Diagnostic Test

Targeted cancer therapies offer great clinical promise, but treatment resistance is common, and basic research aimed at overcoming this challenge is limited by reduced genomic and biologic complexity in artificially induced rodent tumors compared with their human counterparts. Animal models that more faithfully recapitulate genotype-specific human pathology could improve the predictive value of these investigations. Here, a newly identified animal model for oncogenic BRAF-driven cancers is described. With 20,000 new cases in the United States each year, canine invasive transitional cell carcinoma of the bladder (InvTCC) is a common, naturally occurring malignancy that shares significant histologic, biologic, and clinical phenotypes with human muscle invasive bladder cancer. In order to identify somatic drivers of canine InvTCC, the complete transcriptome for multiple tumors was determined by RNAseq. All tumors harbored a somatic mutation that is homologous to the human BRAF(V600E) mutation, and an identical mutation was present in 87% of 62 additional canine InvTCC tumors. The mutation was also detectable in the urine sediments of all dogs tested with mutation-positive tumors. Functional experiments suggest that, like human tumors, canine activating BRAF mutations potently stimulate the MAPK pathway. Cell lines with the mutation have elevated levels of phosphorylated MEK, compared with a line with wild-type BRAF. This effect can be diminished through application of the BRAF(V600E) inhibitor vemurafenib. These findings set the stage for canine InvTCC as a powerful system to evaluate BRAF-targeted therapies, as well as therapies designed to overcome resistance, which could enhance treatment of both human and canine cancers

IMPLICATIONS

This study demonstrates the activating BRAF mutation (V600E), which is found in multiple human cancers, is a driver of canine InvTCC, and highlights a urine-based test for quick diagnosis.

Assessment of tumor characteristics and factors affecting survival in patients with primary metastatic breast carcinoma: a Multicenter Study of the Anatolian Society of Medical Oncology

Primary metastatic breast cancer (PMBC) comprises 3-10% of all BCs. PMBC is a heterogeneous disease. To date, little is known about the tumor characteristics, treatment results, and overall survival (OS) of patients with PMBC. Patients were considered to have PMBC if distant metastasis was evident within 3 months of the initial diagnosis of BC. Between September 2007 and April 2013, 466 PMBC patients were included in this study and analyzed retrospectively. The median age of the patients was 50 (18-90) years. Bone/soft tissue metastases were more frequent in the hormone receptor (HR)(+) human epidermal growth factor receptor (HER)2(-) group compared with the HR(-)HER2(-) and HR(-)HER2(+) groups (p < 0.001), whereas visceral organ metastasis was more frequent in the HR(-)HER2(-) and HR(-)HER2(+) groups (p < 0.001). The OS was affected by Eastern Cooperative Oncology Group performance status, tumor histology, receptor status, and the site of metastasis (p < 0.001, p < 0.001, p < 0.001, and p = 0.011, respectively). According to the first-line systemic treatment choices of the patients, the longest median OS was observed in the HR(+)HER2(+) group who received hormonotherapy combined with trastuzumab after chemotherapy (86 months, 95% CI 23.8-148.1) and the shortest median OS was observed in the HR(-)HER2(-) group who received chemotherapy only (24 months, 95% CI 17.9-30.0) (p < 0.001). Bisphosphonate therapy or radiotherapy had no significant effect on OS (p = 0.733, 0.603). In multivariate analysis, hormonotherapy, chemotherapy + trastuzumab, trastuzumab + hormonotherapy following chemotherapy, and surgery were the most important prognostic factors for OS, respectively (p < 0.001, p = 0.025, p = 0.027, p = 0.029). The general characteristics of the primary tumor are important for the prognosis and survival of patients with PMBC. Interestingly, patients who underwent primary breast tumor surgery, even those at the metastatic stage upon admission, had the longest survival.

The impact of personalized medicine on survival: comparisons of results in metastatic breast, colorectal and non-small-cell lung cancers

Breast, colorectal and lung cancers represent the three most incident forms of cancer worldwide. Among these three "big killers", lung cancer is considered the one with the worst prognosis due to its high mortality even in early stages. Due to their more favorable prognosis, breast and colorectal cancers might appear to have benefited from major advances. Most oncologists who are faced with metastatic non-small cell lung cancer (NSCLC) find the reported results very frustrating when compared with those for metastatic breast (MBC) and colorectal cancers (MCRC). The aim of this analysis was to quantify and compare the relative magnitude of overall survival (OS) improvements in the first-line approaches in metastatic NSCLC, MBC and MCRC through the analysis of the main landmark meta-analyses and randomized clinical trials (RCTs) of commercially available drugs. Five items were considered and analyzed for each cancer. Moreover we evaluated the real clinical impact of the results reported by each item on the entire population; for each "big killer" an overall hazard ratio (HR) was estimated: 0.88 (95%(+) CI: 0.72-1.07) for MBC, 0.94 (95%(+) CI: 0.82-1.07) for MCRC, and about 0.80 (95%(+) CI: 0.73-0.90) for advanced NSCLC. We showed that, in the last decades, these three tumors had important and constant OS improvements reached step by step. The relative magnitude of OS improvement seems higher in metastatic NSCLC than MBC and MCRC.

Prognostic significance of human epidermal receptor (HER)- 3 immunohistochemical expression in patients with metastatic breast cancer

BACKGROUND

Previous reports have shown that human epidermal receptor (HER)-3 overexpression may be associated with poor prognosis in patients with breast cancer, but results have been conflicting. In this study, we sought to investigate the prognostic significance of HER-3 immunohistochemical expression in patients with metastatic breast cancer.

METHODS

We retrospectively analyzed HER-3 immunohistochemical expression profiles in 45 paraffin-embedded specimens from patients who had been treated between 1996 and 2006 in the Department of Oncology of the Uludag University School of Medicine, Bursa, Turkey. Membranous or cytoplasmic dominant expression patterns of HER-3 were analyzed using the Rajkumar score and a cytoplasmic 4-point scoring system, respectively. Progression-free survival (PFS) and overall survival (OS) served as the main outcome measures.

RESULTS

The median PFS in the study participants was 9 months (interquartile range: 4.5-13 months), whereas the median OS was 20 months (interquartile range: 7.5-28 months). Categorization of the patient population according to HER-3 positive immunohistochemical expression did not reveal any statistically significant difference in terms of both PFS (p=0.70) and OS (p=0.81). The results of multivariable Cox regression analysis indicated that tumor size was the only independent predictor of PFS, whereas estrogen and progesterone receptor status was independently associated with OS.

CONCLUSIONS

HER-3 immunohistochemical expression did not correlate with outcomes in Turkish patients with metastatic breast cancer. Although our results suggest that HER-3 expression in cancer specimens is not of prognostic significance, further prospective studies are warranted to confirm these results.

The future of NMR metabolomics in cancer therapy: towards personalizing treatment and developing targeted drugs?

There has been a recent shift in how cancers are defined, where tumors are no longer simply classified by their tissue origin, but also by their molecular characteristics. Furthermore, personalized medicine has become a popular term and it could start to play an important role in future medical care. However, today, a "one size fits all" approach is still the most common form of cancer treatment. In this mini-review paper, we report on the role of nuclear magnetic resonance (NMR) metabolomics in drug development and in personalized medicine. NMR spectroscopy has successfully been used to evaluate current and potential therapies, both single-agents and combination therapies, to analyze toxicology, optimal dose, resistance, sensitivity, and biological mechanisms. It can also provide biological insight on tumor subtypes and their different responses to drugs, and indicate which patients are most likely to experience off-target effects and predict characteristics for treatment efficacy. Identifying pre-treatment metabolic profiles that correlate to these events could significantly improve how we view and treat tumors. We also briefly discuss several targeted cancer drugs that have been studied by metabolomics. We conclude that NMR technology provides a key platform in metabolomics that is well-positioned to play a crucial role in realizing the ultimate goal of better tailored cancer medicine.