Triple-negative breast cancers express receptors for growth hormone-releasing hormone (GHRH) and respond to GHRH antagonists with growth inhibition

Expression of Growth Hormone-Releasing Hormone and Its Receptor Splice Variants in Primary Human Endometrial Carcinomas: Novel Therapeutic Approaches

Antagonists of growth hormone-releasing hormone (GHRH) inhibit the growth of various tumors, including endometrial carcinomas (EC). However, tumoral receptors that mediate the antiproliferative effects of GHRH antagonists in human ECs have not been fully characterized. In this study, we investigated the expression of mRNA for GHRH and splice variants (SVs) of GHRH receptors (GHRH-R) in 39 human ECs and in 7 normal endometrial tissue samples using RT-PCR. Primers designed for the PCR amplification of mRNA for the full length GHRH-R and SVs were utilized. The PCR products were sequenced, and their specificity was confirmed. Nine ECs cancers (23%) expressed mRNA for SV1, three (7.7%) showed SV2 and eight (20.5%) revealed mRNA for SV4. The presence of SVs for GHRH-Rs could not be detected in any of the normal endometrial tissue specimens. The presence of specific, high affinity GHRH-Rs was also demonstrated in EC specimens using radioligand binding studies. Twenty-four of the investigated thirty-nine tumor samples (61.5%) and three of the seven corresponding normal endometrial tissues (42.9%) expressed mRNA for GHRH ligand. Our findings suggest the possible existence of an autocrine loop in EC based on GHRH and its tumoral SV receptors. The antiproliferative effects of GHRH antagonists on EC are likely to be exerted in part by the local SVs and GHRH system.

A potentially effective drug for patients with recurrent glioma: sermorelin

Background

Treatment insensitivity is the main cause of glioma. This study was designed to screen out effective drugs for recurrent gliomas based on the transcriptomics data.

Methods

A total of 1,018 glioma patients with transcriptome sequencing data and clinical data were included in this study. There were 325 patients in the discovery cohort, including 229 primary patients and 92 recurrent patients. There were 693 patients in the validation cohort, including 422 primary patients and 271 relapsed patients. Drug Resistant Scores (DRS) of 4,865 drugs of each patient were used for screening. The analysis and drawing in this study were mainly based on R language.

Results

After high-throughput drug screening, we found that recurrent glioma patients were most sensitive to sermorelin. Further analysis revealed that sermorelin was suitable for recurrent patients with high grade, IDH-wildtype and 1p/19q non-codeletion status. GO and KEGG analyses found that sermorelin may inhibit tumor cell proliferation by cell cycle blocking. Moreover, sermorelin was also related to the immune system process and negatively regulated immune checkpoints and M0 macrophages. Lastly, the Kaplan-Meier method showed the patient's benefit from sermorelin was independent of postoperative adjuvant treatment.

Conclusions

Recurrent glioma patients are sensitive to sermorelin and it makes effect through glioma cells proliferation inhibiting and immune response enhancing.

Treatment of Breast Cancer With Gonadotropin-Releasing Hormone Analogs

Although significant progress has been made in the implementation of new breast cancer treatments over the last three decades, this neoplasm annually continues to show high worldwide rates of morbidity and mortality. In consequence, the search for novel therapies with greater effectiveness and specificity has not come to a stop. Among the alternative therapeutic targets, the human gonadotropin-releasing hormone type I and type II (hGnRH-I and hGnRH–II, respectively) and its receptor, the human gonadotropin-releasing hormone receptor type I (hGnRHR-I), have shown to be powerful therapeutic targets to decrease the adverse effects of this disease. In the present review, we describe how the administration of GnRH analogs is able to reduce circulating concentrations of estrogen in premenopausal women through their action on the hypothalamus–pituitary–ovarian axis, consequently reducing the growth of breast tumors and disease recurrence. Also, it has been mentioned that, regardless of the suppression of synthesis and secretion of ovarian steroids, GnRH agonists exert direct anticancer action, such as the reduction of tumor growth and cell invasion. In addition, we discuss the effects on breast cancer of the hGnRH-I and hGnRH-II agonist and antagonist, non-peptide GnRH antagonists, and cytotoxic analogs of GnRH and their implication as novel adjuvant therapies as antitumor agents for reducing the adverse effects of breast cancer. In conclusion, we suggest that the hGnRH/hGnRHR system is a promising target for pharmaceutical development in the treatment of breast cancer, especially for the treatment of advanced states of this disease.

Expression of GHRH-R, a Potentially Targetable Biomarker, in Triple-negative Breast Cancer

PURPOSE

Growth hormone-releasing hormone (GHRH) has been shown to modify the growth behavior of many cancers, including breast. GHRH is produced by tumor cells, acts in an autocrine/paracrine manner, and requires the presence of GHRH receptor (GHRH-R) on the tumor cells to exert its effects. GHRH activity can be effectively blocked by synthetic antagonists of its receptor and hence, the expression of GHRH-R by tumor cells could serve as a predictor of response to GHRH-R antagonist therapy. In this study, we investigated the expression of GHRH-R in triple-negative breast cancers (TNBC). As TNBCs are morphologically and immunophenotypically heterogenous, the staining results were also correlated with the histologic subtypes of these tumors.

MATERIALS AND METHODS

On the basis of histomorphology and immunophenotype, 134 cases of primary TNBCs were further subdivided into medullary, metaplastic, apocrine, and invasive ductal carcinomas of no special type (IDC-NST). Immunohistochemistry for GHRH-R was performed on paraffin sections and the staining results were assessed semiquantitatively as negative, low expression, moderate, and high expression.

RESULTS

Of the 134 TNBCs, 85 were classified as IDC-NST, 25 as metaplastic, 16 as medullary, and 8 as apocrine carcinoma. Overall, positive reaction for GHRH-R was seen in 77 (57%) of tumors including 66 (77.6%) of IDC-NST. All medullary carcinomas were negative for GHRH-R and, with the exception of 1 case with low expression, none of the metaplastic carcinomas expressed GHRH-R (P<0.005).

CONCLUSIONS

A considerable number of TNBCs are positive for GHRH-R as a predictor of potential response to anti-GHRH-R treatment. This expression however, varies considerably between histologic subtypes of triple-negative breast cancers. Although most medullary and metaplastic carcinomas do not express GHRH-R, three fourths of the IDC-NST show a positive reaction. Testing for GHRH-R expression is therefore advisable if anti-GHRH-R therapy is being considered.

Could gonadotropin-releasing hormone analogs be helpful in the treatment of triple-negative breast cancer?

AIM

Treatment of triple-negative breast cancer (TNBC) imposes great challenges, due to a lack of molecular targets. While use of gonadotropin-releasing hormone (GnRH) analogs has been validated in ER-positive breast cancer, this option has not been investigated in TNBC, even though a significant portion of these tumors upregulate GnRH receptors. We performed a meta-analysis of the literature to evaluate the effect of GnRH analogs in TNBC.

METHODS

Four studies were included in this study.

RESULTS

We detected a non-significant improvement in overall survival with GnRH analogs, while progression-free survival was unchanged.

DISCUSSION

The majority of the trials evaluated in this analysis were designed to test efficacy of GnRH analogs in preventing premature ovarian failure. This may represent a limitation of our study as these trials were not specifically designed to detect differences in survival outcome measures.

CONCLUSION

Our results suggest that GnRH analogs may be useful as a targeted therapy in TNBC. Randomized prospective clinical trials are needed to investigate this hypothesis in the clinic.

The expression of GHRH and its receptors in breast carcinomas with apocrine differentiation-further evidence of the presence of a GHRH pathway in these tumors

Apocrine breast carcinomas were evaluated for the expression of components of the growth hormone-releasing hormone (GHRH) autocrine/paracrine pathway: GHRH and its receptors (GHRH-R), as mammary apocrine carcinomas and epithelium seemed to be uniformly positive for GHRH-R in a pilot study. The apocrine phenotype was determined on the basis of hematoxylin-eosin morphology and a congruent immunohistochemical profile (estrogen receptor negativity, androgen receptor and gross cystic disease fluid protein-15 positivity). Thirty-five formalin-fixed, paraffin-embedded apocrine breast cancers in tissue microarrays and 24 cases using whole-tissue sections were evaluated for GHRH-R and GHRH expression by immunohistochemistry using polyclonal antibodies raised against various domains of GHRH-R and one polyclonal antibody specific for GHRH. GHRH-R positivity was detected in the overwhelming majority (ranging from 90% to 100%) of apocrine breast carcinomas with all but one of the antibodies applied. The expression was usually diffuse with only isolated cases showing positivity in less than 50% of tumor cells. With the PA5-33583 antibody, GHRH-R positivity was seen only in 73% of the cases in at least 50% of the tumor cells. GHRH expression was also present in all but one case tested, with more than 50% of the cells expressing it in 30/34 cases. These results support a high rate of GHRH-R and GHRH expression in apocrine breast carcinomas. Whether these findings can be exploited for the targeted treatment of apocrine breast carcinomas with GHRH antagonists requires further study.

Effects of an Antagonistic Analog of Growth Hormone-Releasing Hormone on Endometriosis in a Mouse Model and In Vitro

Endometriosis is a benign gynecologic disorder causing dysmenorrhea, pelvic pain, and subfertility. Receptors for the growth hormone-releasing hormone (GHRH) were found in endometriotic tissues. Antagonists of GHRH have been used to inhibit the growth of endometriotic endometrial stromal cells. In this study, the GHRH receptor splice variant (SV) 1 was detected in human endometrial tissue samples by Western blots and quantitative reverse transcription polymerase chain reaction (qRT-PCR). The highest messenger RNA (mRNA) and protein levels of SV1 were found in eutopic endometrium from patients with endometriosis compared to ectopic endometriotic tissues and endometrium from normal patients. The highest expression for GHRH mRNA was found by qRT-PCR in ectopic endometriosis lesions. In an in vivo mouse model with human endometrial explants from patients with endometriosis, 10 μg MIA-602 per day resulted in significantly smaller human endometrial xenotransplants after 4 weeks compared to mice treated with vehicle. The endometrial tissues expressed SV1 before and after xenotransplantation. The proliferation of endometrial stromal cells as well as the endometriosis cell lines 12-Z and 49-Z was decreased by exposure to 1 μM MIA-602 after 72 hours. The protein levels of epithelial growth factor receptors in 12-Z and 49-Z cell lines were reduced 48 and 72 hours after the administration of 1 μM MIA-602. MIA-602 decreased the activation of the MAP-kinases ERK-1/2. Our study demonstrates the presence of SV1 receptor as a target for treatment with GHRH antagonist in endometriosis. Endometrial tissues respond to MIA-602 with inhibition of proliferation in vitro and in vivo. The use of MIA-602 could be an effective supplement to the treatment strategies in endometriosis.

Growth Hormone-Releasing Hormone and Its Analogues: Significance for MSCs-Mediated Angiogenesis

Mesenchymal stromal cells (MSCs) are promising candidates for regenerative medicine because of their multipotency, immune-privilege, and paracrine properties including the potential to promote angiogenesis. Accumulating evidence suggests that the inherent properties of cytoprotection and tissue repair by native MSCs can be enhanced by various preconditioning stimuli implemented prior to cell transplantation. Growth hormone-releasing hormone (GHRH), a stimulator in extrahypothalamus systems including tumors, has attracted great attentions in recent years because GHRH and its agonists could promote angiogenesis in various tissues. GHRH and its agonists are proangiogenic in responsive tissues including tumors, and GHRH antagonists have been tested as antitumor agents through their ability to suppress angiogenesis and cell growth. GHRH-R is expressed by MSCs and evolving work from our laboratory indicates that treatment of MSCs with GHRH agonists prior to cell transplantation markedly enhanced the angiogenic potential and tissue reparative properties of MSCs through a STAT3 signaling pathway. In this review we summarized the possible effects of GHRH analogues on cell growth and development, as well as on the proangiogenic properties of MSCs. We also discussed the relationship between GHRH analogues and MSC-mediated angiogenesis. The analyses provide new insights into molecular pathways of MSCs-based therapies and their augmentation by GHRH analogues.

Establishment of an mKate2-Expressing Cell Line for Non-Invasive Real-Time Breast Cancer In Vivo Imaging

PURPOSE

Non-invasive real-time in vivo imaging experiments using mice as animal models have become crucial for understanding cancer development and treatment. In this study, we have developed and validated a new breast cancer cell line MDA-MB-435s that stably express a far-red fluorescence protein (mKate2) and that could serve as a highly valuable cell model for studying breast cancer detection and therapy using in vivo fluorescence imaging in nude mice.

PROCEDURES

The new cell line (MDA-MB-435s-mKate2) was constructed by plasmid transfection. The stability and sensitivity of mKate2, and the cell biological activities, were tested in vitro using different experimental approaches. For its potential use in tumor growth research and drug therapy in vivo, MDA-MB-435s-mKate2 was validated using the immunocompromised Balb/c nude mice tumor model. In addition, the new cell line has been characterized as a luteinizing hormone-releasing hormone receptor (LHRHR) positive cell line.

RESULTS

Firstly, MDA-MB-435s-mKate2 has shown a stable chromosomal integration of the amplified mKate2 gene and good fluorescence sensitivity for detection using a fluorescence reflectance imaging (FRI) device. Compared to its parental cell line, no significant difference in cell migration, proliferation, and clone formation was observed in vitro. Secondly, using the quantification of tumor-fluorescence surface area in live animals, we were able to monitor and detect the tumor progress or tumor inhibition rate (by Paclitaxel treatment) non-invasively and in real-time. Furthermore, MDA-MB-435s-mKate2 has been positively tested for LHRHR; these findings open the possibility to use this cell line for future studies of breast cancer therapy based on LHRH analogs in vivo.

CONCLUSION

In the present research, we have successfully built the MDA-MB-435s-mKate2 cell line that can be used as a suitable cell model for breast cancer therapy and anti-cancer drug evaluation by non-invasive fluorescence imaging in mice.

Antagonistic analogs of growth hormone-releasing hormone increase the efficacy of treatment of triple negative breast cancer in nude mice with doxorubicin; A preclinical study

Introduction

This study evaluated the effects of an antagonistic analog of growth hormone-releasing hormone, MIA-602, on tumor growth, response to doxorubicin, expression of drug resistance genes, and efflux pump function in human triple negative breast cancers.

Methods

HCC1806 (doxorubicin-sensitive) and MX-1 (doxorubicin-resistant), cell lines were xenografted into nude mice and treated with MIA-602, doxorubicin, or their combination. Tumors were evaluated for changes in volume and the expression of the drug resistance genes MDR1 and NANOG. In-vitro cell culture assays were used to analyze the effect of MIA-602 on efflux pump function.

Results

Therapy with MIA-602 significantly reduced tumor growth and enhanced the efficacy of doxorubicin in both cell lines. Control HCC1806 tumors grew by 435%, while the volume of tumors treated with MIA-602 enlarged by 172.2% and with doxorubicin by 201.6%. Treatment with the combination of MIA-602 and doxorubicin resulted in an increase in volume of only 76.2%. Control MX-1 tumors grew by 907%, while tumors treated with MIA-602 enlarged by 434.8% and with doxorubicin by 815%. The combination of MIA-602 and doxorubicin reduced the increase in tumor volume to 256%. Treatment with MIA-602 lowered the level of growth hormone-releasing hormone and growth hormone-releasing hormone receptors and significantly reduced the expression of multidrug resistance (MDR1) gene and the drug resistance regulator NANOG. MIA-602 also suppressed efflux pump function in both cell lines.

Conclusions

We conclude that treatment of triple negative breast cancers with growth hormone-releasing hormone antagonists reduces tumor growth and potentiates the effects of cytotoxic therapy by nullifying drug resistance.

Differential immunostaining of various types of breast carcinomas for growth hormone-releasing hormone receptor - Apocrine epithelium and carcinomas emerging as uniformly positive

Different classes of breast cancers were explored for their positivity for growth hormone-releasing hormone receptors (GHRH-R) in this pilot study, as no systematic evaluation of such tumors has been performed to date. Seventy-two small primary breast carcinomas were evaluated for GHRH-R expression by immunohistochemistry using a polyclonal antibody and a cutoff value of 10% staining. GHRH-R positivity was detected in 58% of all cases, 20/23 (87%) of invasive lobular carcinomas (ILC) and 22/46 (48%) of invasive ductal carcinomas (IDC). GHRH-R positivity was more frequent in grade 2 tumors (86%), as compared to grade 1 (18%) or grade 3 (47%) cancers. GHRH-R expression was not associated with mitotic scores, the Ki-67 labeling indices or nodal status. IDCs with casting-type calcifications on the mammogram showed positivity for GHRH-R in 9/12 (75%) cases. Most importantly, apocrine epithelium, and all 10 apocrine carcinomas added later to the study were GHRH-R-positive. These preliminary results suggest a greater than average GHRH-R expression in ILCs and IDCs associated with casting-type calcifications on the mammogram. Apocrine carcinomas seem uniformly positive for GHRH-R. Whether these findings could indicate a potential role of GHRH-antagonists in targeted treatment of these types of breast cancer requires further studies.

Characterizing the metabolic heterogeneity in human breast cancer xenografts by 3D high resolution fluorescence imaging

We previously reported that tumor mitochondrial redox state and its heterogeneity distinguished between the aggressive and the indolent breast cancer xenografts, suggesting novel metabolic indices as biomarkers for predicting tumor metastatic potential. Additionally, we reported that the identified redox biomarkers successfully differentiated between the normal breast tissue and the cancerous breast tissue from breast cancer patients. The aim of the present study was to further characterize intratumor heterogeneity by its distribution of mitochondrial redox state and glucose uptake pattern in tumor xenografts and to further investigate the metabolic heterogeneity of the clinical biopsy samples. We employed the Chance redox scanner, a multi-section cryogenic fluorescence imager to simultaneously image the intratumor heterogeneity in the mitochondrial redox state and glucose uptake at a high spatial resolution (down to 50 × 50 × 20 μm(3)). The mitochondrial redox state was determined by the ratio of the intrinsic fluorescence signals from reduced nicotinamide adenine dinucleotide (NADH) and oxidized flavoproteins (Fp including FAD, i.e., flavin adenine dinucleotide), and the glucose uptake was measured using a near-infrared fluorescent glucose-analogue, pyropheophorbide 2-deoxyglucosamide (Pyro-2DG). Significant inter- and intratumor metabolic heterogeneity were observed from our imaging data on various types of breast cancer xenografts. The patterns and degrees of heterogeneity of mitochondrial redox state appeared to relate to tumor size and metastatic potential. The glucose uptake was also heterogeneous and generally higher in tumor peripheries. The oxidized and reduced regions mostly corresponded with the lower and the higher pyro-2DG uptake, respectively. However, there were some regions where the glucose uptake did not correlate with the redox indices. Pronounced glucose uptake and high NADH were observed in certain localized areas within the tumor necrotic regions, indicative of the existence of viable cells which was also supported by the H&E staining. Significant heterogeneity of the redox state indices was also observed in clinical specimens of breast cancer patients. As abnormal metabolism including the Warburg effect (high glycolysis) plays important roles in cancer transformation and progression, our observations that reveal the 3D intratumor metabolic heterogeneity as a characteristic feature of breast tumors are of great importance for understanding cancer biology and developing diagnostic and therapeutic methods.

Antagonists of growth hormone-releasing hormone suppress in vivo tumor growth and gene expression in triple negative breast cancers

This study evaluated the effects of a modern antagonistic analog of GHRH on tumor growth and on expression of inflammatory cytokine genes in two models of human triple negative breast cancers (TNBC). The TNBC subtype is refractory to the treatment options available for other hormone-independent breast cancers. Inflammatory cytokines play a major role in the cellular signaling associated with breast cancer pathogenesis and enhance epithelial-mesenchymal transitions (EMT), drug resistance, and metastatic potential. Growth hormone-releasing hormone (GHRH) is a hypothalamic neuropeptide which regulates the synthesis and release of growth hormone by the pituitary and is an autocrine/paracrine growth factor for multiple human cancers. The effects of analogs of GHRH on tumoral cytokine expression have not been previously investigated. Animals bearing xenografts of the human TNBC cell lines, HCC1806 and MX-1, were treated with MIA-602, an antagonistic analog of GHRH. Treatment with MIA-602 significantly reduced tumor growth. We quantified transcript levels of the genes for several inflammatory cytokines. Expression of INFγ, IL-1α, IL-4, IL-6, IL-8, IL-10, and TNFα, was significantly reduced by treatment with MIA-602. We conclude that treatment of TNBC with GHRH antagonists reduces tumor growth through an action mediated by tumoral GHRH receptors and produces a suppression of inflammatory cytokine signaling. Silencing of GHRH receptors in vitro with siRNA inhibited the expression of GHRH-R genes and inflammatory cytokine genes in HCC1806 and MX-1 cells. Further studies on GHRH antagonists may facilitate the development of new strategies for the treatment of resistant cancers.

Combination of GHRH antagonists and docetaxel shows experimental effectiveness for the treatment of triple-negative breast cancers

In preclinical studies, antagonists of growth hormone-releasing hormone (GHRH) have demonstrated inhibitory effects on the growth of various types of cancers expressing the pituitary type of GHRH receptors (pGHRH-R) and/or its active splice variant 1 (SV1). In this study, we investigated the effectiveness of the treatment of MDA-MB-231 human triple-negative breast cancer (TNBC) with GHRH antagonist JMR-132 alone or in combination with docetaxel. Receptor expression in the MDA-MB-231 human breast cancer cell line was evaluated by reverse transcription-polymerase chain reaction (RT-PCR). Cell viability assays were performed on MDA-MB-231 cells treated with JMR-132, docetaxel or in combination. For studies in vivo, a subcutaneous nude mouse xenograft model was used. JMR-132 was administered s.c. at a dose of 10 µg/day and docetaxel at a dose of 10 mg/kg i.p. given on day 1 and 5. Similar regimens were used for the combination of both substances. At the end of the experiment, an mRNA-based human cancer pathway array including 84 major genes was performed on the tumor tissue of mice treated with JMR-132 to elucidate the mechanism of action of GHRH antagonists in vivo. The in vitro proliferation studies revealed that JMR-132 and docetaxel decreased the cell viability in a dose-dependent manner. The combination of both treatments produced a significantly greater inhibition of cell viability compared to the single agents. Treatment of nude mice bearing MDA-MB-231 xenografts with JMR-132 and docetaxel significantly (p<0.05) inhibited tumor growth by 46 and 50%, respectively. Treatment with the combination of JMR-132 and docetaxel led to an inhibition of tumor volume by 71.6% (p<0.001). Polymerase chain reaction array analysis revealed that JMR-132 interacts with signal transduction pathways involved in proliferation, apoptosis and angiogenesis. Our results suggest that GHRH antagonists in combination with taxanes may enhance the efficacy of treatment for patients with TNBC expressing the SV1 and/or the pGHRH receptor.

Growth hormone-releasing hormone receptor splice variant 1 is frequently expressed in oral squamous cell carcinomas

The expression of growth hormone-releasing hormone (GHRH) splice variant 1 (SV1) receptor in neoplastic lesions of the oral cavity was assessed. The sensitivity of HaCaT keratinocytes to GHRH analogs was also evaluated. Thirty-three benign precancerous oral lesions and 27 squamous cell carcinomas of the oral cavity were evaluated by immunohistochemistry for SV1 expression. SV1 expression in HaCaT keratinocytes was assessed by western blot. HaCaT proliferation was evaluated by cell counting. Anti-SV1 immunoreactivity was detected in only 9% (three of 33) precancerous lesions (one hyperplasia and two dysplasias), while 44% (12 of 27) carcinomas were positive for SV1 (p<0.002). GHRH(1-29)NH(2) and GHRH agonist JI-38 stimulated HaCaT proliferation in vitro, and this effect was blocked by GHRH antagonists. These results indicate that SV1 expression may be associated with the transition of precancerous lesions to carcinomas of the oral epithelium. GHRH antagonists may be useful for the management of the disease.

Growth hormone-releasing hormone: not only a neurohormone

Growth hormone-releasing hormone (GHRH) is mostly thought to act by stimulating the production and release of growth hormone from the pituitary. However, this neuropeptide emerges as a rather pleiotropic hormone in view of the identification of various extrapituitary sources for GHRH production, as well as the demonstration of a direct action of GHRH on several tissues other than the pituitary. Non-pituitary GHRH has a wide spectrum of activity, exemplified by its ability to modulate cell proliferation, especially in malignant tissues, to regulate differentiation of some cell types, and to promote healing of skin wounds. These findings extend the role of GHRH and its analogs beyond its accepted regulation of somatotropic activity and indicate new possibilities for therapeutic intervention.

Overexpression of Hedgehog signaling molecules and its involvement in triple-negative breast cancer

The purpose of this study was to investigate the activation of Hedgehog (Hh) signaling molecules and its involvement in triple-negative breast cancer (TNBC). A total of 123 cases of paraffin blocks, including 83 cases of primary breast carcinoma, 30 cases of mammary hyperplasia and 10 cases of normal breast tissue, were immunohistochemically analyzed for Sonic Hedgehog (SHH), Patched-1 (PTCH1), Smoothened (SMO) and glioma-associated oncogene homoglog 1 (GLI1) expression. The expression of SMO and GLI1 in TNBC was significantly increased in comparison to non-triple-negative breast cancer (nTNBC). GLI1 expression manifested an inverse association with the estrogen receptor. The levels of GLI1 expression were increased in lymph node-positive cases. The expression of SHH and SMO was increased in high histological grades. Furthermore, the expression of SMO and GLI1 was correlated with superior tumor stage. The expression of SHH, SMO and GLI1 was significantly increased in breast cancer and mammary hyperplasia. PTCH1 expression was significantly decreased in breast cancer compared to mammary hyperplasia and normal breast tissue. For the first time, clinical evidence has been provided in support of significant roles of Hh signaling in TNBC. Hh signaling is involved in breast ductal changes and malignant transformation. Measures to inhibit Hh activity may improve the prognosis of TNBC patients.

Molecular basis for therapy resistance

Chemoresistance remains the main reason for therapeutic failure in breast cancer as well as most other solid tumours. While gene expression profiles related to prognosis have been developed, so far use of such signatures as well as single markers has been of limited value predicting drug resistance. Novel technologies, in particular with regard to high through-put sequencing holds great promises for future identification of the key "driver" mechanisms guiding chemosensitivity versus resistance in breast cancer as well as other malignant conditions.

Modulation of the BRCA1 Protein and Induction of Apoptosis in Triple Negative Breast Cancer Cell Lines by the Polyphenolic Compound Curcumin

In the current study, we sought to examine the effects of curcumin in a specific type of breast cancer called triple negative breast cancer. These cancers lack expression of the estrogen and progesterone receptors and do not over-express HER2. Current treatment for triple negative breast cancers is limited to cytotoxic chemotherapy, and upon relapse, there are not any therapies currently available. We demonstrate here that the bioactive food compound curcumin induces DNA damage in triple negative breast cancer cells in association with phosphorylation, increased expression, and cytoplasmic retention of the BRCA1 protein. In addition, curcumin promotes apoptosis and prevents anchorage-independent growth and migration of triple negative breast cancer cells. Apoptosis and BRCA1 modulation were not observed in non-transformed mammary epithelial cells, suggesting curcumin may have limited non-specific toxicity. This study suggests that curcumin and potentially curcumin analogues should be tested further in the context of triple negative breast cancer. These results are novel, having never been previously reported, and suggest that curcumin could provide a novel, non-toxic therapy, which could lead to improved survival for patients with triple negative breast cancer. Curcumin should be studied further in this subset of breast cancer patients, for whom treatment options are severely limited.