Increased gene copy number of KIT and VEGFR2 at 4q12 in primary breast cancer is related to an aggressive phenotype and impaired prognosis

Targeting Receptor Tyrosine Kinases as a Novel Strategy for the Treatment of Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) comprises a group of aggressive and heterogeneous breast carcinoma. Chemotherapy is the mainstay for the treatment of triple-negative tumors. Nevertheless, the success of chemotherapeutic treatments is limited by their toxicity and development of acquired resistance leading to therapeutic failure and tumor relapse. Hence, there is an urgent need to explore novel targeted therapies for TNBC. Receptor tyrosine kinases (RTKs) are a family of transmembrane receptors that are key regulators of intracellular signaling pathways controlling cell proliferation, differentiation, survival, and motility. Aberrant activity and/or expression of several types of RTKs have been strongly connected to tumorigenesis. RTKs are frequently overexpressed and/or deregulated in triple-negative breast tumors and are further associated with tumor progression and reduced survival in patients. Therefore, targeting RTKs could be an appealing therapeutic strategy for the treatment of TNBC. This review summarizes the current evidence regarding the antitumor activity of RTK inhibitors in preclinical models of TNBC. The review also provides insights into the clinical trials evaluating the use of RTK inhibitors for the treatment of patients with TNBC.

Molecular targets and therapeutic strategies for triple-negative breast cancer

Triple-negative breast cancer (TNBC) is known for its heterogeneous complexity and is often difficult to treat. TNBC lacks the expression of major hormonal receptors like estrogen receptor, progesterone receptor, and human epidermal growth factor receptor-2 and is further subdivided into androgen receptor (AR) positive and AR negative. In contrast, AR negative is also known as quadruple-negative breast cancer (QNBC). Compared to AR-positive TNBC, QNBC has a great scarcity of prognostic biomarkers and therapeutic targets. QNBC shows excessive cellular growth and proliferation of tumor cells due to increased expression of growth factors like EGF and various surface proteins. This study briefly reviews the limited data available as protein biomarkers that can be used as molecular targets in treating TNBC as well as QNBC. Targeted therapy and immune checkpoint inhibitors have recently changed cancer treatment. Many studies in medicinal chemistry continue to focus on the synthesis of novel compounds to discover new antiproliferative medicines capable of treating TNBC despite the abundance of treatments currently on the market. Drug repurposing is one of the therapeutic methods for TNBC that has been examined. Moreover, some additional micronutrients, nutraceuticals, and functional foods may be able to lower cancer risk or slow the spread of malignant diseases that have already been diagnosed with cancer. Finally, nanomedicines, or applications of nanotechnology in medicine, introduce nanoparticles with variable chemistry and architecture for the treatment of cancer. This review emphasizes the most recent research on nutraceuticals, medication repositioning, and novel therapeutic strategies for the treatment of TNBC.

Endorsement of TNBC Biomarkers in Precision Therapy by Nanotechnology

Breast cancer is a heterogeneous disease which accounts globally for approximately 1 million new cases annually, wherein more than 200,000 of these cases turn out to be cases of triple-negative breast cancer (TNBC). TNBC is an aggressive and rare breast cancer subtype that accounts for 10-15% of all breast cancer cases. Chemotherapy remains the only therapy regimen against TNBC. However, the emergence of innate or acquired chemoresistance has hindered the chemotherapy used to treat TNBC. The data obtained from molecular technologies have recognized TNBC with various gene profiling and mutation settings that have helped establish and develop targeted therapies. New therapeutic strategies based on the targeted delivery of therapeutics have relied on the application of biomarkers derived from the molecular profiling of TNBC patients. Several biomarkers have been found that are targets for the precision therapy in TNBC, such as EGFR, VGFR, TP53, interleukins, insulin-like growth factor binding proteins, c-MET, androgen receptor, BRCA1, glucocorticoid, PTEN, ALDH1, etc. This review discusses the various candidate biomarkers identified in the treatment of TNBC along with the evidence supporting their use. It was established that nanoparticles had been considered a multifunctional system for delivering therapeutics to target sites with increased precision. Here, we also discuss the role of biomarkers in nanotechnology translation in TNBC therapy and management.

Expression of the Immunohistochemical Markers CK5, CD117, and EGFR in Molecular Subtypes of Breast Cancer Correlated with Prognosis

Molecular-based subclassifications of breast cancer are important for identifying treatment options and stratifying the prognosis in breast cancer. This study aimed to assess the prognosis relative to disease-free survival (DFS) and overall survival (OS) in patients with triple-negative breast cancer (TNBC) and other subtypes, using a biomarker panel including cytokeratin 5 (CK5), cluster of differentiation 117 (CD117), and epidermal growth factor receptor (EGFR). This cohort-case study included histologically confirmed breast carcinomas as cohort arm. From a total of 894 patients, 572 patients with early breast cancer, sufficient clinical data, and archived tumor tissue were included. Using the immunohistochemical markers CK5, CD117, and EGFR, two subgroups were formed: one with all three biomarkers negative (TBN) and one with at least one of those three biomarkers positive (non-TBN). There were significant differences between the two biomarker subgroups (TBN versus non-TBN) in TNBC for DFS (p = 0.04) and OS (p = 0.02), with higher survival rates (DFS and OS) in the non-TBN subgroup. In this study, we found the non-TBN subgroup of TNBC lesions with at least one positive biomarker of CK5, CD117, and/or EGFR, to be associated with longer DFS and OS.

Potential epigenetic modifications implicated in triple- to quadruple-negative breast cancer transition: a review

Current research on triple-negative breast cancer (TNBC) has resulted in delineation into the quadruple-negative breast cancer (QNBC) subgroup. Epigenetic modifications such as DNA methylation, histone posttranslational modifications and associated changes in chromatin architecture have been implicated in breast cancer pathogenesis. Herein, the authors highlight genes with observed epigenetic modifications that are associated with more aggressive TNBC/QNBC pathogenesis and possible interventions. Advanced literature searches were done on PubMed/MEDLINE, Scopus and Google Scholar. The results suggest that nine epigenetically altered genes/differentially expressed proteins in addition to the downregulated androgen receptor are associated with TNBC aggressiveness and could be implicated in the TNBC to QNBC transition. Thus, restoring the normal expression of these genes via epigenetic reprogramming could be therapeutically beneficial to TNBC and QNBC patients.

Skeletal muscle metastasis from a gastrointestinal stromal tumor: A case report

RATIONALE

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. Common sites for metastasis are the liver and peritoneum, whereas skeletal muscle metastases are rare.

PATIENT CONCERNS

A 59-year-old man with skeletal muscle metastasis was diagnosed during a period of adjuvant imatinib therapy following the recurrence of GIST of the small intestine.

DIAGNOSIS

The patient was diagnosed with skeletal muscle metastasis of GIST based on immunohistochemistry and molecular pathology analysis results.

INTERVENTION

Extensive resection of the left thigh tumor was performed. The patient underwent whole-exome sequencing of tissue examination. The results suggest that resistance to imatinib may have been developed, and the patient was therefore administered sunitinib instead.

OUTCOMES

Complete remission was observed following sunitinib therapy.

LESSONS

In cases of skeletal muscle metastasis diagnosed during a period of adjuvant imatinib therapy following the recurrence of a GIST of the small intestine, whole exome sequencing may be used to discover more gene variations.

Targeting Different Pathways Using Novel Combination Therapy in Triple Negative Breast Cancer

Triple negative breast cancer (TNBC) is one of the most aggressive subtypes of breast cancer accounting for 15-20% of cases and is defined by the lack of hormonal receptors viz., estrogen receptor (ER), progesterone receptor (PR) and expression of human epidermal growth receptor 2 (HER2). Treatment of TNBC is more challenging than other subtypes of breast cancer due to the lack of markers for the molecularly targeted therapies (ER, PR, and HER-2/ Neu), the conventional chemotherapeutic agents are still the mainstay of the therapeutic protocols of its patients. Despite, TNBC being more chemo-responsive than other subtypes, unfortunately, the initial good response to the chemotherapy eventually turns into a refractory drug-resistance. Using a monotherapy for the treatment of cancer, especially high-grade tumors like TNBC, is mostly worthless due to the inherent genetic instability of tumor cells to develop intrinsic and acquired resistance. Thus, a cocktail of two or more drugs with different mechanisms of action is more effective and could successfully control the disease. Furthermore, combination therapy reveals more, or at least the same, effectiveness with lower doses of every single agent and decreases the likelihood of chemoresistance. Herein, we shed light on the novel combinatorial approaches targeting PARP, EGFR, PI3K pathway, AR, and wnt signaling, HDAC, MEK pathway for efficient treatment of high-grade tumors like TNBC and decreasing the onset of resistance.

Quadruple-negative breast cancer: novel implications for a new disease

Based on the androgen receptor (AR) expression, triple-negative breast cancer (TNBC) can be subdivided into AR-positive TNBC and AR-negative TNBC, also known as quadruple-negative breast cancer (QNBC). QNBC characterization and treatment is fraught with many challenges. In QNBC, there is a greater paucity of prognostic biomarkers and therapeutic targets than AR-positive TNBC. Although the prognostic role of AR in TNBC remains controversial, many studies revealed that a lack of AR expression confers a more aggressive disease course. Literature characterizing QNBC tumor biology and uncovering novel biomarkers for improved management of the disease remains scarce. In this comprehensive review, we summarize the current QNBC landscape and propose avenues for future research, suggesting potential biomarkers and therapeutic strategies that warrant investigation.

The Relationship between KIT Copy Number Variation, Protein Expression, and Angiogenesis in Sporadic Breast Cancer

Background

KIT is a protooncogene that encodes for the KIT oncoprotein, which is a transmembrane tyrosine kinase growth factor receptor that holds a critical role in a variety of normal physiological and pathological processes including angiogenesis. KIT has been shown to be involved in tumorigenesis, contributing to the development of gastrointestinal carcinoma and leukemia. A link between KIT overexpression and breast cancer development has previously been reported. In the current study, we explored KIT gene expression and exonic copy number variants (CNV) and the relationship with angiogenesis (CD34) and the clinicopathological features of breast cancer.

Methods

MLPA technique was used to determine the CNV in 64 breast cancer tumor samples from patients diagnosed with primary sporadic breast cancer. Results were confirmed by quantitative PCR. Expression of KIT and CD34 was determined using immunohistochemistry (IHC).

Results

Our results show that 28.1% of the tumor samples from patients with primary sporadic breast cancer had CNV in the KIT gene. Among the breast tumor samples, 54.7% showed positive KIT expression. The expression of the CD34 angiogenesis marker was reported in 43.8% of the tumor samples as low, 42.2% as moderate and 14.1% as high. A significant correlation between increased CNV of KIT exons, a high level of angiogenesis (CD34) and increased tumor grade was observed (p< 0.05).

Conclusion

A significant correlation between the KIT CNV and the angiogenesis marker was found. Examining KIT expression and CNV has the potential to function as a biomarker for tyrosine kinase inhibitor drugs in breast cancer.

CEP135 isoform dysregulation promotes centrosome amplification in breast cancer cells

The centrosome, composed of two centrioles surrounded by pericentriolar material, is the cell's central microtubule-organizing center. Centrosome duplication is coupled with the cell cycle such that centrosomes duplicate once in S phase. Loss of such coupling produces supernumerary centrosomes, a condition called centrosome amplification (CA). CA promotes cell invasion and chromosome instability, two hallmarks of cancer. We examined the contribution of centriole overduplication to CA and the consequences for genomic stability in breast cancer cells. CEP135, a centriole assembly protein, is dysregulated in some breast cancers. We previously identified a short isoform of CEP135, CEP135mini, that represses centriole duplication. Here, we show that the relative level of full-length CEP135 (CEP135full) to CEP135mini (the CEP135full:mini ratio) is increased in breast cancer cell lines with high CA. Inducing expression of CEP135full in breast cancer cells increases the frequency of CA, multipolar spindles, anaphase-lagging chromosomes, and micronuclei. Conversely, inducing expression of CEP135mini reduces centrosome number. The differential expression of the CEP135 isoforms in vivo is generated by alternative polyadenylation. Directed genetic mutations near the CEP135mini alternative polyadenylation signal reduces the CEP135full:mini ratio and decreases CA. We conclude that dysregulation of CEP135 isoforms promotes centriole overduplication and contributes to chromosome segregation errors in breast cancer cells.

Correlation between important genes of mTOR pathway (PI3K and KIT) in Iranian women with sporadic breast cancer

Background: PI3K/Akt/mTOR pathway is a crucial pathway in the angiogenesis, tumour growth and cell differentiation of several cancers. The PI3K and KIT genes are key genes of this pathway. Previous studies have reported the importance of these genes in the development of gastrointestinal carcinoma, leukaemia, and melanomas. The role of mutations and overexpression of PI3K and KIT genes in breast cancer has been previously proved. This study investigates the correlation between PI3K and KIT gene mutations in sporadic breast cancer. Methods: Multiplex Ligation-dependent Probe Amplification (MLPA) technique was used to determine the Copy Number Variation (CNV) of PI3K and KIT genes in 34 breast cancer tumours and PCR-sequencing was used to detect the mutation in PI3K exons 9 and 20. Results: Our results reported that 27% of patients had CNV of the KIT gene; whereas, 20% and 17.5% of patients, had mutation and CNV in the PI3K gene, respectively. We did not found a significant correlation between the mutations of PI3K and KIT genes. Conclusion: About two-tenth of the patients revealed CNV and lesser than two-tenth indicated mutation in the PI3K gene, whereas one-third of the patients demonstrated CNV in the KIT gene. Thus, administration of the PI3K and KIT gene inhibitor drugs might be proposed to suppress breast cancer in patients with mutation and CNV of each of these individual genes.

Fragment-based in silico modeling of multi-target inhibitors against breast cancer-related proteins

Breast cancer is the most frequent cancer reported in women, being responsible for hundreds of thousands of deaths. Chemotherapy has proven to be effective against this malignant neoplasm depending on different biological factors such as the histopathology, grade, and stage, among others. However, breast cancer cells have become resistant to current chemotherapeutic regimens, urging the discovery of new anti-breast cancer drugs. Computational approaches have the potential to offer promising alternatives to accelerate the search for potent and versatile anti-breast cancer agents. In the present work, we introduce the first multitasking (mtk) computational model devoted to the in silico fragment-based design of new molecules with high inhibitory activity against 19 different proteins involved in breast cancer. The mtk-computational model was created from a dataset formed by 24,285 cases, and it exhibited accuracy around 93% in both training and prediction (test) sets. Several molecular fragments were extracted from the molecules present in the dataset, and their quantitative contributions to the inhibitory activities against all the proteins under study were calculated. The combined use of the fragment contributions and the physicochemical interpretations of the different molecular descriptors in the mtk-computational model allowed the design of eight new molecular entities not reported in our dataset. These molecules were predicted as potent multi-target inhibitors against all the proteins, and they exhibited a desirable druglikeness according to the Lipinski's rule of five and its variants.

Bone Marrow Blood Vessels: Normal and Neoplastic Niche

Blood vessels are among the most important factors in the transport of materials such as nutrients and oxygen. This study will review the role of blood vessels in normal bone marrow hematopoiesis as well as pathological conditions like leukemia and metastasis. Relevant literature was identified by a Pubmed search (1992-2016) of English-language papers using the terms bone marrow, leukemia, metastasis, and vessel. Given that blood vessels are conduits for the transfer of nutrients, they create a favorable situation for cancer cells and cause their growth and development. On the other hand, blood vessels protect leukemia cells against chemotherapy drugs. Finally, it may be concluded that the vessels are an important factor in the development of malignant diseases.

Current advances in biomarkers for targeted therapy in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is a complex heterogeneous disease characterized by the absence of three hallmark receptors: human epidermal growth factor receptor 2, estrogen receptor, and progesterone receptor. Compared to other breast cancer subtypes, TNBC is more aggressive, has a higher prevalence in African-Americans, and more frequently affects younger patients. Currently, TNBC lacks clinically accepted targets for tailored therapy, warranting the need for candidate biomarkers. BiomarkerBase, an online platform used to find biomarkers reported in clinical trials, was utilized to screen all potential biomarkers for TNBC and select only the ones registered in completed TNBC trials through clinicaltrials.gov. The selected candidate biomarkers were classified as surrogate, prognostic, predictive, or pharmacodynamic (PD) and organized by location in the blood, on the cell surface, in the cytoplasm, or in the nucleus. Blood biomarkers include vascular endothelial growth factor/vascular endothelial growth factor receptor and interleukin-8 (IL-8); cell surface biomarkers include EGFR, insulin-like growth factor binding protein, c-Kit, c-Met, and PD-L1; cytoplasm biomarkers include PIK3CA, pAKT/S6/p4E-BP1, PTEN, ALDH1, and the PIK3CA/AKT/mTOR-related metabolites; and nucleus biomarkers include BRCA1, the gluco-corticoid receptor, TP53, and Ki67. Candidate biomarkers were further organized into a "cellular protein network" that demonstrates potential connectivity. This review provides an inventory and reference point for promising biomarkers for breakthrough targeted therapies in TNBC.

Loss of membranous VEGFR1 expression is associated with an adverse phenotype and shortened survival in breast cancer

Angiogenesis is a key process in tumor growth and progression, which is controlled by vascular endothelial growth factors (VEGFs) and their receptors (VEGFRs). In order to better understand the prevalence and prognostic value of VEGFR1 expression in breast cancer, a tissue microarray containing >2,100 breast cancer specimens, with clinical follow‑up data, was analyzed by immunohistochemistry using an antibody directed against the membrane‑bound full‑length receptor protein. The results demonstrated that membranous VEGFR1 staining was detected in all (5 of 5) normal breast specimens. In carcinoma specimens, membranous staining was negative in 3.1%, weak in 6.3%, moderate in 10.9%, and strong in 79.7% of the 1,630 interpretable tissues. Strong staining was significantly associated with estrogen receptor and progesterone receptor expression, but was inversely associated with advanced tumor stage (P=0.0431), high Bloom-Richardson-Ellis Score for Breast Cancer grade and low Ki67 labeling index (both P<0.0001). Cancers with moderate to strong (high) VEGFR1 expression were associated with significantly improved overall survival, as compared with tumors exhibiting negative or weak (low) expression (P=0.0015). This association was also detected in the subset of nodal‑positive cancers (P=0.0018), and in the subset of 185 patients who had received tamoxifen as the sole therapy (P=0.001). In conclusion, these data indicated that membrane‑bound VEGFR1 is frequently expressed in normal and cancerous breast epithelium. In addition, reduced or lost VEGFR1 expression may serve as a marker for poor prognosis in patients with breast cancer, who might not optimally benefit from endocrine therapy.

Molecular profiling, including TERT promoter mutations, of acral lentiginous melanomas

Acral lentiginous melanoma (ALM) is the less common subtype with singular characterization. TERT (human telomerase reverse transcriptase) promoter mutations have being described as recurrent in melanomas and infrequent in ALM, but their real incidence and clinical relevance is unclear. The objectives of this study were to describe the prevalence of TERT promoter mutations in ALM, and correlate with the molecular profile of other drive genes and clinical features. Sixty-one samples from 48 patients with ALM were analyzed. After DNA isolation, the mutation profiles of the hotspot region of BRAF, NRAS, KIT, PDGFRA, and TERT genes were determined by PCR amplification followed by direct Sanger sequencing. KIT, PDGFRA, and VEGFR2 gene amplification was performed by quantitative PCR. Clinical information such as survival, clinical stage, and Breslow tumor classification were obtained from medical records. TERT promoter mutations were found in 9.3% of the cases, BRAF in 10.3%, NRAS in 7.5%, KIT in 20.7%, and PDGFRA in 14.8% of ALM. None of the cases showed KIT, PDGFRA, or VEGFR2 gene amplification. We found an association between KIT mutations and advanced Clark level (IV and V, P=0.043) and TERT promoter mutations with low mitotic index. No other significant associations were observed between mutation profile and patients' clinical features nor survival rates. Oncogenic TERT promoter mutations are present in a fraction of ALMs. No relevant associations were found between TERT mutation status and clinical/molecular features nor survival. Mutations of KIT and PDGFRA are the most common genetic alterations, and they can be therapeutic targets for these patients.

The search for biomarkers to direct antiangiogenic treatment in epithelial ovarian cancer

Antiangiogenic agents have demonstrated improved progression-free survival in women with primary and recurrent epithelial ovarian cancer (EOC). Biomarkers that predict outcomes in patients treated with antiangiogenic agents are being investigated to rationally direct therapy for women most likely to benefit from these agents. Among the most promising plasma-based biomarkers are vascular endothelial growth factor (VEGF)-A, fibroblast growth factor, platelet-derived growth factor, angiopoietin-2, and VEGF receptor-2. While these biomarkers have been correlated with prognosis, they have not been shown to predict benefit, specifically from anti-VEGF therapy, highlighting the need for alternative biomarkers, including molecular and clinical factors, which may be predictive of outcome in women with ovarian cancer treated with antiangiogenic agents. Biomarkers are currently being investigated as secondary outcomes in several ongoing phase II and phase III clinical trials of antiangiogenic agents in patients with EOC. Molecular techniques, such as microarray analyses, and imaging techniques, such as dynamic contrast-enhanced magnetic resonance imaging, positron emission tomography, and single photon emission computed tomography, are also being explored in this field. In this review, we provide a comprehensive overview of current biomarker research, with an emphasis on angiogenic biomarkers associated with EOC.

Altered interphase fluorescence in situ hybridization profiles of chromosomes 4, 8q24, and 9q34 in pancreatic ductal adenocarcinoma are associated with a poorer patient outcome

Most patients with pancreatic ductal adenocarcinoma (PDAC) die within 6 months of diagnosis. However, 20% to 25% patients undergoing total tumor resection remain alive and disease-free 5 years after diagnostic surgery. Few studies on tumor markers have predicted patient prognosis and/or survival. We evaluated the effect of tumor cytogenetic copy number changes detected by interphase fluorescence in situ hybridization on overall survival (OS) of 55 PDAC patients. The prognostic value of copy number changes showing an effect on OS was validated in an external cohort of 44 surgically resected PDAC patients by comparative genomic hybridization arrays, and the genes coded in altered chromosomes with prognostic value were identified by high-density single-nucleotide polymorphism arrays in 20 cases. Copy number changes of chromosomes 4 and 9q34 with gains of 8q24 were independently associated with shorter OS. On the basis of these three chromosomal alterations, a score is proposed that identifies patients with significantly different (P < 0.001) 5-year OS rates: 60% ± 20%, 16% ± 8%, and 0% ± 0%, respectively. Our results show an association between tumor cytogenetics and OS of PDAC patients and provide the basis for further prognostic stratification of patients undergoing complete tumor resection. Further studies to identify specific genes coded in these chromosomes and their functional consequences are necessary to understand the clinical effect of these changes.

The three receptor tyrosine kinases c-KIT, VEGFR2 and PDGFRα, closely spaced at 4q12, show increased protein expression in triple-negative breast cancer

Background

Triple-negative breast cancer (TNBC) is a heterogeneous subgroup of breast cancer with poor prognosis and no targeted therapy available. Receptor tyrosine kinases (RTKs) are emerging targets in anticancer therapy and many RTK-inhibiting drugs are currently being developed. The aim of this study was to elucidate if there is a correlation between the protein expression of three RTKs c-KIT, VEGFR2 and PDGFRα, their gene copy number, and prognosis in TNBC compared to non-TNBC.

Methods

Tumor tissue samples from patients diagnosed with primary breast cancer were stained with immunohistochemistry (IHC) for protein assessment, and with fluorescence in situ hybridization (FISH) for gene copy number determination. Breast cancer mortality (BCM), measured from the date of surgery to death, was used as endpoint.

Results

The cohort included 464 patients, out of which 34 (7.3%) had a TNBC. High expression of the three RTKs was more common in TNBC compared to non-TNBC: c-KIT 49% vs. 10% (P<0.001), PDGFRα 32% vs. 19% (P = 0.07) and VEGFR2 32% vs. 6% (P<0.001). The odds ratio (OR) of c-KIT, VEGFR2 and PDGFRα positivity, adjusted for tumor characteristics, was 6.8, 3.6 and 1.3 times higher for TNBC than for non-TNBC. 73.5% of the TNBC had high expression of at least one of the three investigated receptors, compared to 30.0% of the non-TNBC (P<0.001). Survival analysis showed no significant difference in BCM for TNBC patients with high vs. low c-KIT, PDGFRα or VEGFR2 protein expression. 193 (42%) tumors were evaluated with FISH. No correlation was seen between increased gene copy number and TNBC, or between increased gene copy number and high protein expression of the RTK.

Conclusion

c-KIT, VEGFR2 and PDGFRα show higher protein expression in TNBC compared to non-TNBC. Further investigation clarifying the importance of these RTKs in TNBC is encouraged, as they are possible targets for anticancer therapy.

Effect of melatonin on tumor growth and angiogenesis in xenograft model of breast cancer

As neovascularization is essential for tumor growth and metastasis, controlling angiogenesis is a promising tactic in limiting cancer progression. Melatonin has been studied for their inhibitory properties on angiogenesis in cancer. We performed an in vivo study to evaluate the effects of melatonin treatment on angiogenesis in breast cancer. Cell viability was measured by MTT assay after melatonin treatment in triple-negative breast cancer cells (MDA-MB-231). After, cells were implanted in athymic nude mice and treated with melatonin or vehicle daily, administered intraperitoneally 1 hour before turning the room light off. Volume of the tumors was measured weekly with a digital caliper and at the end of treatments animals underwent single photon emission computed tomography (SPECT) with Technetium-99m tagged vascular endothelial growth factor (VEGF) C to detect in vivo angiogenesis. In addition, expression of pro-angiogenic/growth factors in the tumor extracts was evaluated by membrane antibody array and collected tumor tissues were analyzed with histochemical staining. Melatonin in vitro treatment (1 mM) decreased cell viability (p<0.05). The breast cancer xenografts nude mice treated with melatonin showed reduced tumor size and cell proliferation (Ki-67) compared to control animals after 21 days of treatment (p<0.05). Expression of VEGF receptor 2 decreased significantly in the treated animals compared to that of control when determined by immunohistochemistry (p<0.05) but the changes were not significant on SPECT (p>0.05) images. In addition, there was a decrease of micro-vessel density (Von Willebrand Factor) in melatonin treated mice (p<0.05). However, semiquantitative densitometry analysis of membrane array indicated increased expression of epidermal growth factor receptor and insulin-like growth factor 1 in treated tumors compared to vehicle treated tumors (p<0.05). In conclusion, melatonin treatment showed effectiveness in reducing tumor growth and cell proliferation, as well as in the inhibition of angiogenesis.

Tamoxifen integromics and personalized medicine: dynamic modular transformations underpinning response to tamoxifen in breast cancer treatment

Recent advances in pharmacogenomics technologies allow bold steps to be taken towards personalized medicine, more accurate health planning, and personalized drug development. In this framework, systems pharmacology network-based approaches offer an appealing way for integrating multi-omics data and set the basis for defining systems-level drug response biomarkers. On the road to individualized tamoxifen treatment in estrogen receptor-positive breast cancer patients, we examine the dynamics of the attendant pharmacological response mechanisms. By means of an "integromics" network approach, we assessed the tamoxifen effect through the way the high-order organization of interactome (i.e., the modules) is perturbed. To accomplish that, first we integrated the time series transcriptome data with the human protein interaction data, and second, an efficient module-detecting algorithm was applied onto the composite graphs. Our findings show that tamoxifen induces severe modular transformations on specific areas of the interactome. Our modular biomarkers in response to tamoxifen attest to the immunomodulatory role of tamoxifen, and further reveal that it deregulates cell cycle and apoptosis pathways, while coordinating the proteasome and basal transcription factors. To the best of our knowledge, this is the first report that informs the fields of personalized medicine and clinical pharmacology about the actual dynamic interactome response to tamoxifen administration.

Study on lung cancer cells expressing VEGFR2 and the impact on the effect of RHES combined with radiotherapy in the treatment of brain metastases

INTRODUCTION

Brain metastases are often accompanied by edema. Endostatin therapy can prevent tumor tissue edema. Therefore, we investigated the therapeutic effects of endostatin combined with radiotherapy in the treatment of brain metastases of non-small cell lung cancer (NSCLC) and assessed the relations between the effect and vascular endothelial growth factor receptor 2 (VEGFR2) expression.

PATIENTS AND METHODS

Eighty patients with brain metastases of NSCLC were randomly divided into a combination therapy group and a radiotherapy-alone group, each group with 40 patients. The short-term effective rate, overall survival time, cerebral edema index, and adverse reactions were observed, and the expressions of VEGFR2 protein and KDR gene in primary lesions were detected via immunohistochemical methods and fluorescence in-situ hybridization (FISH) in all patients.

RESULTS

Compared with the radiotherapy-alone group, brain edema was significantly relieved (P = .003) and there were no marked adverse reactions in the combination therapy group. Regarding the short-term effective rate, there was no statistical significance in the total population (n = 80, 90% vs. 75%, P = .07), but there was statistical significance in cases of positive VEGFR2 (93% vs. 67.7%, P = .012) or positive KDR gene (94.4% vs. 47.3%, P = .002) in both groups. For overall survival time, there was no statistical significance in total population (n = 80, P = .35), positive VEGFR2 patients (P = .109), and positive KDR gene patients (P = .147).

CONCLUSION

Compared with radiotherapy alone, endostatin combined with radiotherapy can relieve brain edema in patients with brain metastases of NSCLC and can obtain a better short-term effective rate in patients with positive VEGFR2 or positive KDR gene, but endostatin therapy does not significantly improve overall survival time.

Recombinant human endostatin combined with radiotherapy in the treatment of brain metastases of non-small cell lung cancer

OBJECTIVE

Since brain metastases (BM) is often accompanied by edema, and endostatin (ES) can prevent tumor tissue edema, we investigated the therapeutic effects of ES combined with radiotherapy in the treatment of BM of NSCLC. We also determined the patients who are suitable for this therapy.

METHODS

Eighty patients with BM of NSCLC were randomly divided into combination group and radiotherapy alone group. The primary endpoint was overall response rate, and secondary endpoints were overall survival time, cerebral edema index and adverse reactions. These were observed and the expressions of vascular endothelial growth factor receptor 2 (VEGFR2) protein and KDR gene in primary lesions were detected with immunohistochemical method and fluorescence in situ hybridization.

RESULTS

Compared with radiotherapy alone, brain edema was significantly reduced in the ES group (P = 0.003) without marked adverse reactions. For the overall response rate, there was no statistical significant difference between the two groups (control, 90 % vs. ES, 75 %, P = 0.07), but there was statistical significance in the patients with positive VEGFR2 (93 vs. 67.7 %, P = 0.012) or positive KDR gene (94.4 vs. 47.3 %, P = 0.002). In overall survival time, there was no statistical significance in the two groups (P = 0.35), in the tumors with positive VEGFR2 (P = 0.109) or with positive KDR gene (P = 0.147).

CONCLUSION

Compared with radiotherapy alone, ES combined with radiotherapy can reduce brain edema in NSCLC patients with BM and obtain better short-term response rate in tumors with positive VEGFR2 or positive KDR gene, but does not improve the overall survival.

Anti-KIT monoclonal antibody inhibits imatinib-resistant gastrointestinal stromal tumor growth

Gastrointestinal stromal tumor (GIST) is the most common sarcoma of the gastrointestinal tract and arises from the interstitial cells of Cajal. It is characterized by expression of the receptor tyrosine kinase CD117 (KIT). In 70-80% of GIST cases, oncogenic mutations in KIT are present, leading to constitutive activation of the receptor, which drives the proliferation of these tumors. Treatment of GIST with imatinib, a small-molecule tyrosine kinase inhibitor, inhibits KIT-mediated signaling and initially results in disease control in 70-85% of patients with KIT-positive GIST. However, the vast majority of patients eventually develop resistance to imatinib treatment, leading to disease progression and posing a significant challenge in the clinical management of these tumors. Here, we show that an anti-KIT monoclonal antibody (mAb), SR1, is able to slow the growth of three human GIST cell lines in vitro. Importantly, these reductions in cell growth were equivalent between imatinib-resistant and imatinib-sensitive GIST cell lines. Treatment of GIST cell lines with SR1 reduces cell-surface KIT expression, suggesting that mAb-induced KIT down-regulation may be a mechanism by which SR1 inhibits GIST growth. Furthermore, we also show that SR1 treatment enhances phagocytosis of GIST cells by macrophages, indicating that treatment with SR1 may enhance immune cell-mediated tumor clearance. Finally, using two xenotransplantation models of imatinib-sensitive and imatinib-resistant GIST, we demonstrate that SR1 is able to strongly inhibit tumor growth in vivo. These results suggest that treatment with mAbs targeting KIT may represent an alternative, or complementary, approach for treating GIST.

Pairwise shared genomic segment analysis in three Utah high-risk breast cancer pedigrees

Background

We applied a new weighted pairwise shared genomic segment (pSGS) analysis for susceptibility gene localization to high-density genomewide SNP data in three extended high-risk breast cancer pedigrees.

Results

Using this method, four genomewide suggestive regions were identified on chromosomes 2, 4, 7 and 8, and a borderline suggestive region on chromosome 14. Seven additional regions with at least nominal evidence were observed. Of particular note among these total twelve regions were three regions that were identified in two pedigrees each; chromosomes 4, 7 and 14. Follow-up two-pedigree pSGS analyses further indicated excessive genomic sharing across the pedigrees in all three regions, suggesting that the underlying susceptibility alleles in those regions may be shared in common. In general, the pSGS regions identified were quite large (average 32.2 Mb), however, the range was wide (0.3 – 88.2 Mb). Several of the regions identified overlapped with loci and genes that have been previously implicated in breast cancer risk, including NBS1, BRCA1 and RAD51L1.

Conclusions

Our analyses have provided several loci of interest to pursue in these high-risk pedigrees and illustrate the utility of the weighted pSGS method and extended pedigrees for gene mapping in complex diseases. A focused sequencing effort across these loci in the sharing individuals is the natural next step to further map the critical underlying susceptibility variants in these regions.