Overcoming negative predictions of microRNA expressions to gemcitabine response with FOLFIRINOX in advanced pancreatic cancer patients.

FOLFIRINOX is superior to gemcitabine in patients with pancreatic cancer, but this regimen is associated with toxicity and biomarkers for response are warranted. MicroRNAs can mediate drug resistance and could provide predictive information. Altered expressions of several microRNAs including miR-21-5p, miR-10b-5p and miR-34a-5p have been previously linked to a worse response to gemcitabine. We investigated the influence of expression levels in tumor tissue of those three microRNAs on outcome to FOLFIRINOX. Twenty-nine patients with sufficient formalin-fixed paraffin-embedded tumor tissue were identified. There was no significant association between high and low expression groups for these three microRNA. We conclude that polychemotherapy combination can overcome intrinsic negative prognostic factors.

FOLFIRINOX for locally advanced pancreatic cancer: a systematic review and patient-level meta-analysis.

BACKGROUND: 35% of patients with pancreatic cancer have unresectable locally advanced disease at diagnosis. Several studies have examined systemic chemotherapy with FOLFIRINOX (leucovorin and fluorouracil plus irinotecan and oxaliplatin) in patients with locally advanced pancreatic cancer. We aimed to assess the effectiveness of FOLFIRINOX as first-line treatment in this patient population. METHODS: We systematically searched Embase, MEDLINE (OvidSP), Web of Science, Scopus, PubMed Publisher, Cochrane, and Google Scholar from July 1, 1994, to July 2, 2015, for studies of treatment-naive patients of any age who received FOLFIRINOX as first-line treatment of locally advanced pancreatic cancer. Our primary outcome was overall survival. Secondary outcomes were progression-free survival; rates of grade 3 or 4 adverse events; and the proportion of patients who underwent radiotherapy or chemoradiotherapy, surgical resection after FOLFIRINOX, and R0 resection. We evaluated survival outcomes with the Kaplan-Meier method with patient-level data. Grade 3 or 4 adverse events, and the proportion of patients who underwent subsequent radiotherapy or chemoradiotherapy or resection, were pooled in a random-effects model. FINDINGS: We included 13 studies comprising 689 patients, of whom 355 (52%) patients had locally advanced pancreatic cancer. 11 studies, comprising 315 patients with locally advanced disease, reported survival outcomes and were eligible for patient-level meta-analysis. Median overall survival from the start of FOLFIRINOX ranged from 10·0 months (95% CI 4·0-16·0) to 32·7 months (23·1-42·3) across studies with a pooled patient-level median overall survival of 24·2 months (95% CI 21·7-26·8). Median progression-free survival ranged from 3·0 months (95% CI not calculable) to 20·4 months (6·5-34·3) across studies with a patient-level median progression-free survival of 15·0 months (95% 13·8-16·2). In ten studies comprising 490 patients, 296 grade 3 or 4 adverse events were reported (60·4 events per 100 patients). No deaths were attributed to FOLFIRINOX toxicity. The proportion of patients who underwent radiotherapy or chemoradiotherapy ranged from 31% to 100% across studies. In eight studies, 154 (57%) of 271 patients received radiotherapy or chemoradiotherapy after FOLFIRINOX. The pooled proportion of patients who received any radiotherapy treatment was 63·5% (95% CI 43·3-81·6, I(2) 90%). The proportion of patients who underwent surgical resection for locally advanced pancreatic cancer ranged from 0% to 43%. The proportion of patients who had R0 resection of those who underwent resection ranged from 50% to 100% across studies. In 12 studies, 91 (28%) of 325 patients underwent resection after FOLFIRINOX. The pooled proportion of patients who had resection was 25·9% (95% CI 20·2-31·9, I(2) 24%). R0 resection was reported in 60 (74%) of 81 patients. The pooled proportion of patients who had R0 resection was 78·4% (95% CI 60·2-92·2, I(2) 64%). INTERPRETATION: Patients with locally advanced pancreatic cancer treated with FOLFIRINOX had a median overall survival of 24·2 months-longer than that reported with gemcitabine (6-13 months). Future research should assess these promising results in a randomised controlled trial, and should establish which patients might benefit from radiotherapy or chemoradiotherapy or resection after FOLFIRINOX. FUNDING: None.

Cytomegalovirus reactivation and its clinical impact in patients with solid tumors.

Cytomegalovirus reactivation can be life threatening. However, little evidence on its incidence in solid cancers is available. Therefore our single center Cytomegalovirus polymerase chain reaction database with altogether 890 CMV positive blood serum samples of mainly hematological and oncological patients was retrospectively analyzed to examine the occurrence of Cytomegalovirus reactivation in patients with solid tumors, resulting in 107 patients tested positive for Cytomegalovirus reactivation. Seventeen patients with solid cancer and a positive CMV-PCR test were identified, of which eight patients had clinically relevant CMV disease and received prompt antiviral treatment. Five patients fully recovered, but despite prompt antiviral treatment three patients died. Among these three patients two had significant co-infections (in one case EBV and in the other case Aspergillus) indicating that that CMV reactivation was at least one factor contributing to sepsis. The patient with the EBV co-infection was treated in an adjuvant therapy setting for breast cancer and died due to Cytomegalovirus and Epstein-Barr virus associated pneumonia despite intensive therapy. The other two patients had progressive disease of an underlying pancreatic cancer at the time of CMV diagnosis. One patient died due to attendant uncontrollable Aspergillus pneumonia, the other patient most likely died independent from CMV disease because of massively progressive underlying disease. Cytomegalovirus reactivation and disease might be underestimated in routine clinical practice. In our retrospective analysis we show that approximately 50 % of our patients suffering from solid cancers with a positive Cytomegalovirus polymerase chain reaction also had clinically relevant Cytomegalovirus disease requiring antiviral therapy.

Relations of vitamin D status, gender and type 2 diabetes in middle-aged Caucasians.

Vitamin D (Vit D) deficiency may be linked to the development of obesity-associated complications such as insulin resistance and type 2 diabetes. We therefore evaluated the relationship of Vit D serum concentrations with metabolic parameters and type 2 diabetes in middle-aged Caucasian men and women. One thousand six hundred and thirty-one Caucasians (832 males, 58.8 ± 9.7 years; 799 females, 59.7 ± 10.7 years) were evaluated in a cross-sectional study. Vit D status was assessed by measuring the serum concentration of 25-hydroxyvitamin D3 [25(OH)D3]. Type 2 diabetes prevalence was ascertained by medical history, fasting plasma glucose concentrations, oral glucose tolerance testing and/or glycosylated hemoglobin. Men displayed higher crude or seasonally adjusted 25(OH)D3 serum concentrations than women (24.64 ± 10.98 vs. 22.88 ± 11.6 ng/ml; P < 0.001). Strong associations between body mass index (BMI) and 25(OH)D3 were observed in both genders (P < 0.001). Seasonally adjusted levels of 25(OH)D3 revealed stronger associations with type 2 diabetes in women than men (P < 0.001). However, adjustment for BMI and other confounding variables revealed an independent inverse association of 25(OH)D3 with diabetes only in women (P < 0.001), whereas the association was abrogated in men. Using a 15 ng/ml 25(OH)D3 cutoff for binary comparison, adjusted odds ratios for having newly diagnosed or known type 2 diabetes more than doubled (2.95 [95 % CI 1.37-4.89] and 3.26 [1.59-6.68], respectively), in women below the cutoff. We conclude that in women, but not in men, low 25(OH)D3 serum levels are independently associated with type 2 diabetes. These findings suggest sex-specific effects of Vit D in the pathogenesis of type 2 diabetes.

Triple negative breast cancers express receptors for LHRH and are potential therapeutic targets for cytotoxic LHRH-analogs, AEZS 108 and AEZS 125.

BACKGROUND: Triple negative breast cancer (TNBC) is a distinct subtype of breast cancer burdened with a dismal prognosis due to the lack of effective therapeutic agents. Receptors for LHRH (luteinizing hormone-releasing hormone) can be successfully targeted with AEZS-108 [AN-152], an analog of LHRH conjugated to doxorubicin. Our study evaluates the presence of this target LHRH receptor in human specimens of TNBC and investigates the efficacy and toxicity of AEZS-108 in vivo. We also studied in vitro activity of AEZS-125, a new LHRH analog conjugated with the highly potent natural compound, Disorazol Z. METHODS: 69 human surgical specimens of TNBC were investigated for LHRH-R expression by immunohistochemistry. Expression of LHRH-R in two TNBC cell lines was evaluated by real time RT-PCR. Cytotoxicity of AEZS-125 was evaluated by Cell Titer Blue cytoxicity assay. LHRH- receptor expression was silenced with an siRNA in both cell lines. For the in vivo experiments an athymic nude mice model xenotransplanted with the cell lines, MDA-MB-231 and HCC 1806, was used. The animals were randomised to three groups receiving solvent only (d 1, 7, 14, i.v.) for control, AEZS-108 (d 1, 7, 14, i.v.) or doxorubicin at an equimolar dose (d 1, 7, 14, i.v.). RESULTS: In human clinical specimens of TNBC, expression of the LHRH-receptor was present in 49% (n = 69).HCC 1806 and MDA-MB-231 TNBC cells expressed mRNA for the LHRH-receptor. Silencing of the LHRH-receptor significantly decreased the cytotoxic effect of AEZS-108. MDA-MB-231 and HCC 1806 tumors xenografted into nude mice were significantly inhibited by treatment with AEZS-108; doxorubicin at equimolar doses was ineffective.As compared to AEZS 108, the Disorazol Z - LHRH conjugate, AEZS-125, demonstrated an increased cytotoxicity in vitro in HCC 1806 and MDA-MB-231 TNBC; this was diminished by receptor blockade with synthetic LHRH agonist (triptorelin) pretreatment. CONCLUSION: The current study confirms that LHRH-receptors are expressed by a significant proportion of TNBC and can be successfully used as homing sites for cytotoxic analogs of LHRH, such as AEZS-108 and AEZS-125.

Targeted therapy in advanced metastatic colorectal cancer: current concepts and perspectives.

The introduction of new cytotoxic substances as well as agents that target vascular endothelial growth factor (VEGF) and epidermal growth factor receptor (EGFR) signaling has improved clinical outcome of patients with metastatic colorectal cancer (mCRC). In this review we summarize the most relevant clinical data on VEGF and EGFR targeting regimens in mCRC. The effects of available treatment strategies for mCRC are often temporary, with resistance and disease progression developing in most patients. Thus, new treatment strategies are urgently needed. Some GI peptides including gastrin and gastrin releasing peptide, certain growth factors such as insulin-like growth factor-I and II and neuropeptides such as growth hormone releasing hormone (GHRH) are implicated in the growth of CRC. Experimental investigations in CRC with antagonistic analogs of bombesin/gastrin-releasing peptide, GHRH, and with cytotoxic peptides that can be targeted to peptide receptors on tumors, are summarized in the second part of the review.

Female gender may predict response to FOLFIRINOX in patients with unresectable pancreatic cancer: a single institution retrospective review.

FOLFIRINOX is a highly active regimen for the treatment of patients with unresectable pancreatic cancer. However, treatment with FOLFIRINOX is associated with relevant toxicity and predictors for response to therapy are warranted. We retrospectively analyzed 49 patients with unresectable pancreatic cancer treated with FOLFIRINOX in order to evaluate a possible predictive role of clinical parameters and tumor characteristics for response to chemotherapy. Tumor samples were characterized histopathologically before treatment and expression of p53 and Ki67 was analyzed using automated immunohistochemistry. Overall survival (OS) and progression-free survival (PFS) were estimated by the Kaplan-Meier method. The overall objective response rate was 55.1%, the disease control rate was 70.6%. Female gender was associated with a significantly higher disease control rate of 91.7 compared to 48.0% in male patients (p=0.001) which reached 100% in female patients when primarily treated compared to treatment after surgical resection and relapse (77.8%, p=0.057). For all patients median PFS was 3.5 months (95% CI, 2.7-4.3 months) and median OS was 13 months (95% CI, 9.4-16.6 months). Female patients showed a tendency towards a longer median PFS (5.0 months, 95% CI, 3.6-6.4 months) compared to males (3.0 months, 95% CI, 2.4-3.6 months) (p=0.099). Serum levels of CA19.9 and CEA were significantly higher in female patients compared to male patients (p=0.037, p=0.05). Tumors of patients with response to FOLFIRINOX showed a higher expression level of p53 and Ki67 as well as higher serum levels of CA19.9 compared to non-responders, which was statistically not significant. Our study indicates that female gender is a positive predictor for therapy response to FOLFIRINOX in patients with unresectable pancreatic cancer. Female gender in turn was associated with increased levels of tumor markers CEA and CA19.9 and patients with higher serum levels of CA19.9 were more responsive to FOLFIRINOX.

Systemic effect of catumaxomab in a patient with metastasized colorectal cancer: a case report.

BACKGROUND: Catumaxomab, the first anti-EpCAM antibody, was approved in 2009 for the treatment of malignant ascites in cancer patients with EpCAM positive tumors. We consider this case of interest as treatment with catumaxomab not only prolonged the puncture-free interval but also showed a systemic effect in a patient with metastasized colorectal cancer by regression of a pulmonary metastasis. CASE PRESENTATION: We describe the case of a 78 year old patient initially diagnosed with locally advanced colon cancer and one synchronous liver metastasis in September 2010 who was treated by hemicolectomy and simultaneous atypical liver resection. During adjuvant chemotherapy the patient developed a peritoneal carcinomatosis with ascites in March 2011. Palliative chemotherapy was not well tolerated and therefore refused by the patient. Because of disease progression in June 2011 with one pulmonary metastasis and clinically predominant ascites an immunotherapy with intraperitoneal catumaxomab was started in December 2011. After treatment with catumaxomab a puncture free survival of 12 months as well as a regression of the pulmonary lesion was achieved until January 2013. CONCLUSION: This case suggests that treatment with catumaxomab does not only improve quality of life by local suppression of malignant ascites but also might have a systemic antitumor effect.

Targeting triple-negative breast cancer through the somatostatin receptor with the new cytotoxic somatostatin analogue AN-162 [AEZS-124].

Previously, we have shown that the targeted cytotoxic somatostatin (sst) analogue AN-162 [AZSE-124] inhibits the growth of MDA-MB-231 human breast cancers xenografted into nude mice. In this study, we examined the trafficking of AN-162 into the cell, the expression of the somatostatin receptors (sstr) in specimens of human triple-negative breast cancers (TNBC), and the effect of AN-162 on HCC 1806 human TNBC xenografts. The expression of sstr in TNBC tumor samples was investigated by immunohistochemical staining. The expression of sstr in HCC 1806 was evaluated by reverse transcription PCR. Internalization studies with I-labeled AN-162 were carried out and the autofluorescence sign of doxorubicin moiety in the cell nucleus after incubation with AN-162 was measured using a fluorescence assay. The effects of AN-162 on the growth of HCC 1806 xenografted into nude mice were studied. A fluorescence microscopy cytotoxicity assay in vitro to detect cell death after treatment with AN-162 was also carried out. About 28% of TNBC tumor specimens showed a positive staining for sstr subtype 2a. HCC 1806 expresses all five subtypes of sstr. In the fluorescence cytotoxicity assay, dead HCC 1806 cells were found 24 h after incubation with AN-162. The growth of HCC 1806 tumors in nude mice was significantly inhibited by treatment with AN-162. AN-162 was internalized into the HCC 1806 cells and doxorubicin moiety was detected in the cell nuclei. This study is the first to show that the trafficking of the cytotoxic sst analogue AN-162 into the cell is mediated by sstr. Our work shows that the growth of xenografted HCC 1806 TNBCs can be effectively inhibited in vivo with AN-162. This investigation provides information on the mechanism of action and efficacy of this new targeted cytotoxic sst analogue and identifies in this relation the sstr as a favorable therapeutic target in TNBC.

GHRH antagonist when combined with cytotoxic agents induces S-phase arrest and additive growth inhibition of human colon cancer.

Treatment of colon cancer with an antagonist of growth hormone-releasing hormone (GHRH), JMR-132, results in a cell cycle arrest in S-phase of the tumor cells. Thus, we investigated the effect of JMR-132 in combination with S-phase-specific cytotoxic agents, 5-FU, irinotecan and cisplatin on the in vitro and in vivo growth of HT-29, HCT-116 and HCT-15 human colon cancer cell lines. In vitro, every compound inhibited proliferation of HCT-116 cells in a dose-dependent manner. Treatment with JMR-132 (5 µM) combined with 5-FU (1.25 µM), irinotecan (1.25 µM) or cisplatin (1.25 µM) resulted in an additive growth inhibition of HCT-116 cells in vitro as shown by MTS assay. Cell cycle analyses revealed that treatment of HCT-116 cells with JMR-132 was accompanied by a cell cycle arrest in S-phase. Combination treatment using JMR-132 plus a cytotoxic drug led to a significant increase of the sub-G 1 fraction, suggesting apoptosis. In vivo, daily treatment with GHRH antagonist JMR-132 decreased the tumor volume by 40-55% (p < 0.001) of HT-29, HCT-116 and HCT-15 tumors xenografted into athymic nude mice. Combined treatment with JMR-132 plus chemotherapeutic agents 5-FU, irinotecan or cisplatin resulted in an additive tumor growth suppression of HT-29, HCT-116 and HCT-15 xenografts to 56-85%. Our observations indicate that JMR-132 enhances the antiproliferative effect of S-phase-specific cytotoxic drugs by causing accumulation of tumor cells in S-phase.

Combination of gastrin-releasing peptide antagonist with cytotoxic agents produces synergistic inhibition of growth of human experimental colon cancers.

We investigated the efficacy of a powerful antagonist of bombesin/gastrin-releasing peptide (BN/GRP) RC-3940-II administered as a single agent or in combination with cytotoxic agents on the growth of HT-29, HCT-116 and HCT-15 human colon cancer in vitro and in vivo. GRP-receptor mRNA and protein were found in all three cell lines tested. Exposure of HT-29 cells to 10 µM RC-3940-II led to an increase in the number of cells blocked in S phase and G 2/M and cells with lower G(0)/G(1) DNA content. Similar changes on the cell cycle traverse of HT-29 cells could also be seen at lower concentrations of RC-3940-II (1 µM) after pretreatment with 100 nM GRP (14-27), indicating a dose-dependent mechanism of action based on the blockage of BN/GRP induced proliferation of tumor cells at lower concentrations. Daily in vivo treatment with BN/GRP antagonist RC-3940-II decreased the volume of HT-29, HCT-116 and HCT-15 tumors xenografted into athymic nude mice by 25 to 67% (p < 0.005). Combined treatment with RC-3940-II and chemotherapeutic agents 5-FU and irinotecan resulted in a synergistic tumor growth suppression of HT-29, HCT-116 and HCT-15 xenografts by 43% to 78%. In HT-29 and HCT-116 xenografts the inhibition for the combinations of RC-3940-II and irinotecan vs. single substances (p < 0.05) was significantly greater. These findings support the use of RC-3940-II as an anticancer agent and may help to design clinical trials using RC-3940-II in combinations with cytotoxic agents.

Antagonists of growth hormone-releasing hormone inhibit growth of androgen-independent prostate cancer through inactivation of ERK and Akt kinases.

The management of castration-resistant prostate cancer (CRPC) presents a clinical challenge because of limitations in efficacy of current therapies. Novel therapeutic strategies for the treatment of CRPC are needed. Antagonists of hypothalamic growth hormone-releasing hormone (GHRH) inhibit growth of various malignancies, including androgen-dependent and independent prostate cancer, by suppressing diverse tumoral growth factors, especially GHRH itself, which acts as a potent autocrine/paracrine growth factor in many tumors. We evaluated the effects of the GHRH antagonist, JMR-132, on PC-3 human androgen-independent prostate cancer cells in vitro and in vivo. JMR-132 suppressed the proliferation of PC-3 cells in vitro in a dose-dependent manner and significantly inhibited growth of PC-3 tumors by 61% (P < 0.05). The expression of GHRH, GHRH receptors, and their main splice variant, SV1, in PC-3 cells and tumor xenografts was demonstrated by RT-PCR and Western blot. The content of GHRH protein in PC-3 xenografts was lowered markedly, by 66.3% (P < 0.01), after treatment with JMR-132. GHRH induced a significant increase in levels of ERK, but JMR-132 abolished this outcome. Our findings indicate that inhibition of PC-3 prostate cancer by JMR-132 involves inactivation of Akt and ERK. The inhibitory effect produced by GHRH antagonist can result in part from inactivation of the PI3K/Akt/mammalian target of rapamycin and Raf/MEK/ERK pathways and from the reduction in GHRH produced by cancer cells. Our findings support the role of GHRH as an autocrine growth factor in prostate cancer and suggest that antagonists of GHRH should be considered for further development as therapy for CRPC.

A correlation of endocrine and anticancer effects of some antagonists of GHRH.

GHRH receptor antagonists inhibit growth and metastasis of a large number of experimental tumors expressing the pituitary GHRH receptor (pGHRH-R) and its major splice variant SV1. In this study, using Western blot, we demonstrated that DBTRG-05 and U-87MG human glioblastoma cell lines express pGHRH-R at levels 6-15 times higher than SV1. To reveal a correlation between the anticancer activity and the endocrine potency on inhibition of GH release, we compared the antitumor effect of GHRH antagonists JV-1-63 and MZJ-7-138 on growth of DBTRG-05 human glioblastomas grafted into athymic nude mice with their inhibitory potency on GH release. JV-1-63 strongly suppressed the stimulated GH secretion induced by clonidine in rats and inhibited the exogenous GHRH-induced GH surge by 88-99% in vivo and in vitro. MZJ-7-138 decreased the stimulated GH secretion by 58% in vitro and showed only a tendency to inhibit GH secretion in vivo. The strong inhibitor of GH release JV-1-63 reduced tumor growth of DBTRG-05 glioblastomas in nude mice by 46%, while the weak GH release suppressor MZJ-7-138 did not have an effect. Exposure of DBTRG-05 cells to the GHRH antagonists in vitro caused an upregulation of mRNA expression for pGHRH-R and a downregulation of SV1 expression, with JV-1-63 having significantly greater effects than MZJ-7-138. Our results demonstrate that a positive correlation exists between the endocrine potency and the antiproliferative efficacy of GHRH antagonists in tumors strongly expressing pGHRH-R.

Targeting gastrin releasing peptide receptors: New options for the therapy and diagnosis of cancer.

Gastrin-releasing peptide (GRP), the mammalian bombesin (BN), appears to be involved in the growth of several neoplasms. BN/GRP receptors (BN/GRP-Rs) are expressed in a variety of cancer cells and have limited distribution in normal human tissue. Thus inhibition of BN/GRP-Rs represents an attractive target for pharmacological treatment of some human malignancies. This review will focus on intracellular signaling pathways which have been characterized to mediate BN/GRP-dependent receptor biological effects as well as on various approaches to target BN/GRP-Rs for therapeutic and diagnostic interventions in human malignancies.

A role for low hepatic copper concentrations in nonalcoholic Fatty liver disease.

OBJECTIVES: Copper has a role in antioxidant defense, lipid peroxidation, and mitochondrial function, and copper deficiency has been linked to atherogenic dyslipidemia. We aimed to investigate the potential role of copper availability in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). METHODS: Patients with NAFLD (n=124) were compared to patients with chronic hepatitis C (n=50), hemochromatosis (n=35), alcoholic liver disease (n=13), autoimmune hepatitis (n=11), and control subjects (n=27). We determined liver and serum copper concentrations with correlation to clinical, histological, and biochemical parameters in humans. The effect of dietary copper restriction on liver histology and intermediary metabolism in rats was investigated. RESULTS: Hepatic copper concentrations in patients with NAFLD were lower than in control subjects (17.9+/-8.4 vs. 31.4+/-8.2 microg/g; P<0.001) and in patients with other liver diseases (P<0.05 for all liver diseases). In patients with NAFLD, lower liver copper was correlated with more pronounced hepatic steatosis (R=-0.248; P=0.010), fasting glucose (R=-0.245; P=0.008), and components of the metabolic syndrome (MetS; R=0.363; P<0.001). Patients with nonalcoholic steatohepatitis (NASH; n=31) had lower hepatic copper concentrations than those with simple steatosis (n=93; P=0.038). Restriction of dietary copper in rats induced hepatic steatosis and insulin resistance (IR). CONCLUSIONS: Reduced hepatic copper concentrations are found in human NAFLD and are associated with more pronounced hepatic steatosis, NASH, and components of the MetS. The development of hepatic steatosis and IR in response to dietary copper restriction in rats suggests that copper availability may be involved in the development of NAFLD.

Targeted cytotoxic somatostatin analog AN-162 inhibits growth of human colon carcinomas and increases sensitivity of doxorubicin resistant murine leukemia cells.

The effect of the targeted cytotoxic somatostatin (SST) analog AN-162, consisting of doxorubicin (DOX) conjugated to SST carrier RC-121, was investigated on the growth of human colorectal cancer (CRC) cell lines HT-29, HCT-15, and HCT-116 and a DOX-resistant mouse leukemia cell line P388/R84. mRNA for SST-receptors and high affinity binding sites for SST were detected in all CRC cell lines and in P388/R84 cells. In contrast to DOX alone, AN-162 blocked HCT-116 cells and P388/R84 cells in S/G2 phase and increased the number of apoptotic cells. In vivo, AN-162 reduced the volume of CRC xenografts more effectively than its unconjugated components. Our results suggest that AN-162 inhibits growth of experimental CRC more effectively than DOX and increases sensitivity of DOX resistant human leukemia cells.

Triple-negative breast cancers express receptors for luteinizing hormone-releasing hormone (LHRH) and respond to LHRH antagonist cetrorelix with growth inhibition.

The aim of the present study was to evaluate the expression of receptors for luteinizing hormone-releasing hormone (LHRH) in human specimens of triple-negative breast cancers (TNBC). In addition, we used in vitro and in vivo models of TNBC to investigate if these receptors are suitable targets for the treatment with the LHRH antagonist cetrorelix. Receptors for LHRH were expressed in all tumor samples and in the TNBC cell lines HCC1806 and HCC1937. The proliferation of both TNBC cell lines was significantly inhibited in vitro by 1 microM cetrorelix. Injections of 3 mg cetrorelix on day 1 and 21 resulted in a significant growth inhibition of HCC1806 tumors xenografted into nude mice. Tumors of mice treated with cetrorelix expressed less mRNA for EGFR and HER3 receptors than untreated tumors. After treatment of cells with Cetrorelix a flow cytometric analysis of the cell cycle revealed a decrease in S-phase. Given the low toxicity and clinical availability of cetrorelix, this peptide antagonist should be considered for phase II studies in patients with advanced TNBC.

GHRH antagonist causes DNA damage leading to p21 mediated cell cycle arrest and apoptosis in human colon cancer cells.

We investigated the mechanisms of inhibitory effect of growth hormone-releasing hormone (GHRH) antagonist JMR-132 on the growth of HT29, HCT-116 and HCT-15 human colon cancer cells in vitro and in vivo. High-affinity binding sites for GHRH and mRNA for GHRH and splice variant-1 (SV1) of the GHRH receptor were found in all three cell lines tested. Proliferation of HT-29, HCT-116 and HCT-15 cells was significantly inhibited in vitro by JMR-132. Time course studies revealed that the treatment of human HCT-116 colon cancer cells with 10 muM GHRH antagonist JMR-132 causes a significant DNA damage as shown by an increase in olive tail moment (OTM) and loss of inner mitochondrial membrane potential (Delta Psi m). Western blotting demonstrated a time-dependent increase in protein levels of phospho-p53 (Ser46), Bax, cleaved caspase-9, -3, cleavage of poly(ADP-ribose)polymerase (PARP) and a decrease in Bcl-2 levels. An augmentation in cell cycle checkpoint protein p21(Waf1/Cip1) was accompanied by a cell cycle arrest in S-phase. DNA fragmentation visualized by the comet assay and the number of apoptotic cells increased time dependently as determined by flow cytometric annexinV and PI staining assays. In vivo, JMR-132 decreased the volume of HT-29, HCT-116 and HCT-15 tumors xenografted into athymic mice up to 75% (p < 0.05) and extended tumor doubling time (p < 0.001). Our observations suggest that GHRH antagonist JMR-132 exerts its antiproliferative effect on experimental colon cancer cells through p21(Waf1/Cip1) mediated S-phase arrest along with apoptosis involving the intrinsic pathway.

Preclinical evaluation of properties of a new targeted cytotoxic somatostatin analog, AN-162 (AEZS-124), and its effects on tumor growth inhibition.

In view of findings that various tumors express receptors for somatostatin, a new targeted cytotoxic analog of somatostatin, AN-162 (AEZS-124), consisting of doxorubicin linked through glutaric acid to the somatostatin octapeptide RC-121 was developed in our laboratory. We studied the toxicity in vivo and the effect of AN-162 on growth of the MDA-MB-231 estrogen-independent human breast cancer cell line xenografted into nude mice. AN-162 induced significant tumor growth inhibition compared with the control and the group treated with doxorubicin in equimolar doses. We also evaluated the stability of AN-162 in various sera in vitro, as this conjugate is susceptible to hydrolysis by serum carboxylesterase enzymes in the circulation. This study shows for the first time that AN-162 is a safe and effective compound for the treatment of experimental breast cancer. Our findings support the concept of targeted chemotherapy based on cytotoxic peptide analog AN-162 for the treatment of breast cancers and other cancers expressing somatostatin receptors.

Retinol-binding protein 4 in polycystic ovary syndrome--association with steroid hormones and response to pioglitazone treatment.

CONTEXT: Polycystic ovary syndrome (PCOS) is frequently associated with insulin resistance. OBJECTIVE: The aim of the study was to investigate a putative role of the adipokines retinol-binding protein 4 (RBP4), adiponectin, and visfatin in a cohort of patients with PCOS and their response to treatment with pioglitazone. DESIGN AND SETTING: We conducted a randomized, controlled, double-blind study at a tertiary referral center. PATIENTS AND INTERVENTIONS: Forty premenopausal women with PCOS were allocated to receive treatment with either pioglitazone (30 mg/d) or a placebo for a period of 3 months. MAIN OUTCOME MEASURES: Serum concentrations of RBP4, adiponectin, and visfatin were determined along with metabolic and hormonal parameters before and after treatment. RESULTS: Serum adiponectin concentrations were higher after treatment with pioglitazone (P = 0.003), whereas RBP4 levels tended to decrease (P = 0.06), and visfatin concentrations remained unchanged. We found RBP4 serum concentrations at baseline to be positively correlated with serum levels of testosterone (R = 0.446; P = 0.005), 17-OH progesterone (R = 0.345, P = 0.037), and dehydroepiandrosterone sulfate (R = 0.347; P = 0.041). However, these correlations were abolished after treatment with pioglitazone. Patients with high RBP4 levels had significantly higher hirsutism scores (P = 0.038 before and P = 0.034 after treatment). In contrast, serum adiponectin concentrations were related to parameters of impaired glucose metabolism, and no significant associations were detected for visfatin. CONCLUSIONS: Our results suggest that RBP4 may contribute to endocrine changes and to the phenotypic manifestation of patients with PCOS because higher RBP4 concentrations are associated with higher androgen levels and higher clinical hirsutism scores independently of pioglitazone treatment. The molecular involvement of RBP4 in human steroid metabolism requires further clarification.