Receptors for luteinizing hormone releasing hormone expressed on human renal cell carcinomas can be used for targeted chemotherapy with cytotoxic luteinizing hormone releasing hormone analogues

Controlled ovarian stimulation therapy as a potential risk for the development and progression of renal cell carcinomas: A case report and literature review

Renal Cell Carcinoma (RCC) is the most common type of cancer in the kidney and is mostly asymptomatic. Previous studies have supported the important role of sex hormones in RCC pathophysiology and that targeted hormone receptor therapy, such as estrogen receptor targeting, is a promising treatment strategy. However, to the best of our knowledge, it remains unknown whether hormonal therapy, such as controlled ovarian stimulation for in vitro fertilization, serves a role in the development and progression of RCC. The present report describes a case of RCC developed after a fertility stimulation therapy and provides a summary of the known literature on the role of hormone receptors in the development and progression of RCC. A 35-year-old woman received fertility stimulation treatment with follitropin alfa 900 units, human chorionic gonadotropic hormone 5,000 units, injectable leuprolide 1 mg/0.2 ml and cetrotide 0.25 mg. The patient presented to the hospital with shortness of breath and weight loss. The patient had no known genetic predisposition or family history of malignancies and no exposure to chemicals. The patient never used tobacco, alcohol or recreational drugs. Imaging revealed a 17x19 mm, heterogeneously enhancing, and partially exophytic mass in the right kidney. After partial nephrectomy, the pathological evaluation confirmed the diagnosis of clear cell RCC. To the best of our knowledge, this was the first time that a case of ovarian stimulation therapy was associated with the development of RCC. This case raises concerns about the potential oncogenic effect of controlled ovarian stimulation therapy in RCC promotion, suggesting a need for systematic research to clarify the clinical significance of existing pre-clinical data.

Expression of Luteinizing Hormone-Releasing Hormone (LHRH) and Type-I LHRH Receptor in Transitional Cell Carcinoma Type of Human Bladder Cancer

Bladder cancer (BC) is the tenth most frequently detected cancer in both sexes. Type-I luteinizing hormone-releasing hormone (LHRH) receptor (LHRH-R-I) is expressed not only in the pituitary, but also in several types of cancer disease. There are few data about LHRH-R-I expression in human BC. This study aimed to investigate the expression of LHRH and LHRH-R-I in the transitional cell carcinoma (TCC) type of human BC. RNA was extracted from 24 human bladder tumor specimens and three BC cell lines. RT-PCR was performed to detect mRNA for LHRH and LHRH-R-I. The protein of LHRH-R-I was further studied by immunohistochemistry (IHC), ligand competition assay, and Western Blot. PCR products of LHRH were found in 19 of 24 (79%) specimens and mRNA of LHRH-R-I was detected in 20 of 24 specimens (83%). Positive immunostaining for LHRH-R-I with different expression intensity was found in all samples examined, showing negative correlation with TCC grade. Radioligand binding studies also showed the presence of specific LHRH-R-I and high affinity binding of LHRH analogs. The high incidence of LHRH-R in BC suggests that it could serve as a molecular target for therapy of human BC with cytotoxic LHRH analogs or modern powerful antagonistic analogs of LHRH.

A multicenter open-label randomized phase II trial of paclitaxel plus EP-100, a novel LHRH receptor-targeted, membrane-disrupting peptide, versus paclitaxel alone for refractory or recurrent ovarian cancer

OBJECTIVE

This randomized open-label phase II study evaluated the safety and clinical activity of EP-100 plus weekly paclitaxel in patients with recurrent ovarian cancer expressing positive LHRH receptor.

METHODS

In a limited "run-in" dose escalation phase for EP-100, six patients were treated with ascending dose levels (13 mg/m², 20 mg/m², 30 mg/m²). In the randomized phase, patients received weekly paclitaxel (80 mg/m² intravenously) plus twice weekly EP-100 (30 mg/m² intravenously; combination arm) or weekly paclitaxel alone (80 mg/m² intravenously; paclitaxel arm). The primary study endpoint was overall response rate (ORR).

RESULTS

Forty-four patients were then randomized to either the experimental combination arm (n = 23) or the standard of care paclitaxel monotherapy arm (n = 21). The ORR was 35% (95%CI 16%-57%) for the combination arm and 33% (95% CI 15%-57%) for the paclitaxel arm. An interesting observation from an unplanned analysis was that a subset of patients with target liver lesions showed a greater overall response rate to the combination (69%) compared to paclitaxel alone (16%). The frequency of treatment-related grade 3-4 adverse events was similar between treatment arms: 48% vs 43% for the combination and paclitaxel arms, respectively.

CONCLUSIONS

ORR in the EP-100 combination arm was similar to that in the group treated with paclitaxel alone; however, a subset of patients with liver metastases appeared to benefit from the combination. The addition of EP-100 did not appear to augment the adverse event profile of paclitaxel and was well tolerated.

Immunohistochemical expression of receptors for luteinizing hormone-releasing hormone (LHRHR) in muscle-invasive Urothelial carcinoma of urinary bladder: a potential predictive marker for targeted cytotoxic LHRH hybrid analogs

Background

Recurrent disease following failed chemotherapy for muscle-invasive urothelial carcinoma (UC) has no universally accepted treatment guidelines. Receptors for luteinizing hormone-releasing hormone (LHRHR) have recently been identified in urothelial cancer cell lines as well as tissue samples. These receptors can be used as target for cytotoxic hybrid analogs of LHRH. The aim of this study was to determine the frequency of LHRHR expression in muscle invasive UC by immunohistochemistry.

Methods

Fifty-two cases, including TURBTs (31) and cystectomies (21), with at least muscle invasive UC were retrieved. Of 52 patients, 41 (78.8%) were male and 11 (21.1%) were female, with age ranging from 50 to 84 years. Immunohistochemical staining for LHRHR antibody (N-20, Santa Cruz, 1:50) was performed using the LSAB method. Membranous and/or granular cytoplasmic staining was considered as a positive reaction. Scoring was based on the percentage of positive tumor cells; negative (no staining), 1+ (1–25%), 2+ (26–50%), 3+ (51–75%), 4+ (> 75%).

Results

Of 52 UC cases, 32 (61%) were AJCC stage T2, 17 (33%) were T3, and 3 (6%) were T4. Of 52 cases, 30 (58%) were positive and 22 (42%) were negative for LHRHR. Of the 30 positive cases, 16 (53%) were scored 1+, 7 (23%) 2+, 5 (17%) 3+ and 2 (7%) 4 + .

Conclusions

More than half of the cases expressed LHRHR. Two-thirds of cases demonstrated focal (< 50%) immunoreactivity, which may cause false negative results in limited tissue samples. Immunohistochemical expression of LHRHR in UC can be a predictive marker for potential efficacy of LHRH cytotoxic hybrid analogs.

Enhanced Immunotherapy with LHRH-R Targeted Lytic Peptide in Ovarian Cancer

Here, we examined the role of EP-100 [luteinizing hormone-releasing hormone (LHRH) ligand joined to a lytic peptide], improving the efficacy of immune checkpoint blockade. LHRH-R-positive murine ovarian cancer cells (ID8, IG10, IF5, and 2C12) were sensitive to EP-100 and were specifically killed at low micromolar levels through LHRH-R. EP-100 increased PD-L1 levels on murine ovarian cancer cells. In vivo syngeneic mouse models (ID8 and IG10) demonstrated that single-agent EP-100 reduced tumor volume, tumor weight, and ascites volume. The greatest reductions in tumor and ascites volume were observed with the combination of EP-100 with an anti-PD-L1 antibody. Immune profiling analysis showed that the population of CD8⁺ T cells, natural killer cells, dendritic cells, and macrophages were significantly increased in tumor and ascitic fluid samples treated with anti-PD-L1, EP-100, and the combination. However, monocytic myeloid suppressor cells, B cells, and regulatory T cells were decreased in tumors treated with anti-PD-L1, EP-100, or the combination. In vitro cytokine arrays revealed that EP-100 induced IL1α, IL33, CCL20, VEGF, and Low-density lipoprotein receptor (LDLR) secretion. Of these, we validated increasing IL33 levels following EP-100 treatment in vitro and in vivo; we determined the specific biological role of CD8⁺ T-cell activation with IL33 gene silencing using siRNA and Cas9-CRISPR approaches. In addition, we found that CD8⁺ T cells expressed very low level of LHRH-R and were not affected by EP-100. Taken together, EP-100 treatment had a substantial antitumor efficacy, particularly in combination with an anti-PD-L1 antibody. These results warrant further clinical development of this combination.

Application of luteinizing hormone-releasing hormone-ferrosoferric oxide nanoparticles in targeted imaging of breast tumors

Background

Ferrosoferric oxide (Fe₃O₄) nanoparticles are a commonly used magnetic resonance imaging (MRI) reagent. Luteinizing hormone-releasing hormone (LHRH) is highly expressed on the surfaces of tumors, but its expression is low or absent in the corresponding normal tissues, allowing it to be used for targeted imaging and treatment.

Methods

We prepared Fe₃O₄ nanoparticles using a chemical co-precipitation method, performed coupling with chitosan to prepare LHRH-Fe₃O₄ nanoparticles, and explored the application value of LHRH-Fe₃O₄ nanoparticles in targeted imaging and treatment of breast tumors through in vitro and in vivo experiments.

Results

The particle size of the LHRH-Fe₃O₄ nanoparticles was 10 nm, and they could be taken in by human MCF-7 breast cancer cells. The nanomaterial had low cytotoxicity. In vivo MRI experiments showed that LHRH-Fe₃O₄ could effectively concentrate on the tumor under the action of a magnetic field. It also had a good negative enhancement effect that significantly reduced the signal intensity of the T₂ field, allowing it to be used as a contrast agent of the T₂ field.

Conclusion

LHRH-Fe₃O₄ nanoparticles serve the purpose of targeting contrast agents to target sites and are expected to be used for targeted imaging and treatment of cancers with high LHRH expression.

LHRH receptor expression in sarcomas of bone and soft tissue

AIM

Luteinizing hormone releasing hormone (LHRH) is a neurohormone, secreted by the hypothalamus, which regulates the secretion of gonadotropins, luteinizing hormone (LH) and follicle stimulating hormone (FSH) from the pituitary. LHRH acts by binding to receptors located in the pituitary gland. These receptors (LHRH receptors) have also been found in the cytoplasm of many tumor cells that involve both the reproductive and non-reproductive organs. These receptors have been demonstrated in prostate and breast cancers, endometrial carcinomas, renal cell carcinoma, lymphoma, carcinoma of liver, pancreas and skin. So far, the expression of LHRH receptors on sarcomas (i.e. malignant tumors of mesenchymal origin) has not been studied, except for endometrial sarcomas. It has also been demonstrated that both LHRH agonists and antagonists can down-regulate these receptors and thus inhibit these tumor cells. Another major therapeutic implication is that these receptors can be targeted specifically by peptides conjugated to anti-cancer drugs. The purpose of this study was to determine if LHRH receptors are expressed in primary and/or metastatic sarcomas of human origin.

METHODS

We looked at LHRH receptor expression in 38 consecutive sarcoma specimens, using immunohistochemistry. The specimens were either from office biopsy or from resected tumor; these were confirmed as sarcomas by histopathological examination. The receptor staining characteristics and the staining intensity were also documented. The pattern of staining was classified either as "focal or diffuse staining of the cytoplasm" and the intensity of staining was graded on a scale from 1+ to 4+.

RESULTS

Positive receptor staining was seen in 25 of the 38 (66%) specimens. Twelve of the specimens stained diffusely and 13 had focally positive staining. Three tumors had 1+ staining, 10 had 2+ staining, six had 3+ staining, and six tumors had 4+ staining. The tumors included undifferentiated pleomorphic sarcoma, synovial sarcoma, osteosarcoma, myofibroblastic sarcoma, myxofibrosarcoma, liposarcoma, dermatofibrosarcoma protuberans, metastatic chondrosarcoma and chordoma.

CONCLUSION

Sarcomas express LHRH receptors with a varying incidence and degree. Our study suggests that those sarcomas that are LHRH receptor positive could potentially be treated with targeted chemotherapy.

A case study on the potential angiogenic effect of human chorionic gonadotropin hormone in rapid progression and spontaneous regression of metastatic renal cell carcinoma during pregnancy and after surgical abortion

BACKGROUND

Treatment possibilities of metastatic renal cell carcinoma (mRCC) have recently changed dramatically prolonging the overall survival of the patients. This kind of development brings new challenges for the care of mRCC.

CASE PRESENTATION

A 22 year-old female patient with translocation type mRCC, who previously had been treated for nearly 5 years, became pregnant during the treatment break period. Follow-up examinations revealed a dramatic clinical and radiological progression of mRCC in a few weeks therefore the pregnancy was terminated. A few days after surgical abortion, CT examination showed a significant spontaneous regression of the pulmonary metastases, and the volume of the largest manifestation decreased from ca. 30 to 3.5 cm(3) in a week. To understand the possible mechanism of this spectacular regression, estrogen, progesterone and luteinizing hormone receptors (ER, PGR and LHR, respectively) immuno-histochemistry assays were performed on the original surgery samples. Immuno-histochemistry showed negative ER, PGR and positive LHR status suggesting the possible angiogenic effect of human chorionic gonadotropin hormone (hCG) in the background.

CONCLUSION

We hypothesize that pregnancy may play a causal role in the progression of mRCC via the excess amount of hCG, however, more data are necessary to validate the present notions and the predictive role of LHR overexpression.

Novel LHRH-receptor-targeted cytolytic peptide, EP-100: first-in-human phase I study in patients with advanced LHRH-receptor-expressing solid tumors

Purpose

To conduct a phase I study determining the safety, pharmacokinetics and preliminary efficacy of EP-100, a novel anticancer drug consisting of natural luteinizing-hormone-releasing hormone (LHRH) ligand linked to a cationic membrane-disrupting peptide.

Methods

Patients with advanced, solid tumors, positive for LHRH receptor by immunohistochemistry (IHC), received EP-100 weekly or twice weekly for 3 of 4 weeks in a 28 day cycle. A modified Fibonacci 3 + 3 dose-escalation schema was used. Initial cohorts received EP-100 once weekly (cohorts 1–7, 0.6–7.8 mg/m², n = 21). Later cohorts received doses twice weekly (cohorts 7–11, 7.8–40 mg/m², n = 16).

Results

LHRH-receptor expression was confirmed by IHC in 52 of 89 consented patients; 37 patients received at least 1 dose. Cohorts receiving doses of 5.2 mg/m² and above achieved therapeutic levels from in vitro studies Clearance was rapid (mean half-life 7.1 ± 3.8 to 15.9 ± 3.6 min). The maximum-tolerated dose was not reached at the highest dose evaluated (40 mg/m² twice weekly). Grade 2 increase in alanine aminotransferase/serum aspartate aminotransferase in one patient resolved, did not recur upon re-treatment, and was not observed in other patients. The only drug-related adverse event was transient infusion-related dermatologic reactions (10 patients). No complete or partial tumor responses were observed; seven patients had stable disease of 16 weeks.

Conclusions

EP-100 was well tolerated in patients with advanced, LHRH-receptor-expressing solid tumors. The recommended phase 2 dose is 40 mg/m² twice weekly for 3 of 4 weeks per cycle.

Electronic supplementary material

The online version of this article (doi:10.1007/s00280-014-2424-x) contains supplementary material, which is available to authorized users.

Receptor-targeted therapy of human experimental urinary bladder cancers with cytotoxic LH-RH analog AN-152 [AEZS- 108]

Many bladder cancers progress to invasion with poor prognosis; new therapeutic methods are needed. We developed a cytotoxic LH-RH analog, AN-152 (AEZS-108) containing doxorubicin (DOX), for targeted therapy of cancers expressing LHRH receptors. We investigated the expression of LH-RH receptors in clinical bladder cancers and in HT-1376, J82, RT-4 and HT-1197 human bladder cancer lines. The effect of analog, AN-152, on growth of these tumor lines xenografted into nude mice was analyzed. Using molecular and functional assays, we also evaluated the differences between the effects of AN-152, and DOX alone. We demonstrated the expression of LH-RH receptors on 18 clinical bladder cancers by immunohistochemistry and on four human urinary bladder cancer lines HT-1376, J82, RT-4 and HT-1197 by Western blotting and binding assays. AN-152 powerfully inhibited growth of these bladder cancers in nude mice. AN-152 exerted greater effects than DOX and was less toxic. DOX activated strong multidrug resistance mechanisms in RT-4 and HT-1197 cancers, while AN-152 had no or less such effect. PCR assays and in vitro studies revealed differences in the action of AN-152 and DOX on the expression of genes involved in apoptosis. These results suggest that targeted cytotoxic LH-RH analog, AN-152 (AEZS- 108), should be examined for treatment of patients with LH-RH receptor positive invasive bladder cancers.

Receptor-mediated tumor targeting based on peptide hormones

IMPORTANCE OF THE FIELD

Tumor targeting with peptides is based on the discovery that receptors for many regulatory peptides are overexpressed in tumor cells, compared with their expression in normal tissues. Consequently, these peptides and their analogues can be used as carriers/targeting moieties for the preparation of diagnostic and therapeutic agents that have increased selectivity and decreased peripheral toxicity.

AREAS COVERED IN THIS REVIEW

Here an overview is given of the most relevant gonadotropin-releasing hormone (GnRH) and somatostatin derivatives, as well as of their applications in cancer diagnosis and therapy. For this purpose, recently published data in these areas (mostly articles published from 2000 to 2009) were reviewed.

WHAT THE READER WILL GAIN

In contrast to other regulatory peptides that stimulate the tumor growth, GnRH and somatostatin derivatives have inhibitory effect; therefore, they were used primarily for the preparation of various conjugates to be used in targeted chemotherapy, targeted radiotherapy, photodynamic therapy, boron neutron capture therapy and cancer diagnosis. Some of these conjugates have already found clinical applications, whereas others are now in preclinical and clinical trials.

TAKE HOME MESSAGE

Tumor targeting with hormone peptides provides a basis for the development of new diagnostic and therapeutic approaches for cancer.

Quantitative measurement of multifunctional quantum dot binding to cellular targets using flow cytometry

Semiconductor nanocrystals such as quantum dots (QDs) are a potentially powerful resource in the fields of flow cytometry and fluorescence microscopy. QD size and fluorescence characteristics offer attractive features for use in targeted delivery systems and detection by flow cytometry. While quantitative measurements of a variety of fluorescent molecules are routinely performed, fluorophores for which no calibration standards exist, such as QDs, pose a problem for quantitation in flow cytometry. Our goal was to develop a targeted nanoparticle delivery platform as well as a corresponding method to accurately and quantitatively assess the performance of this system. We synthesized surface-modified QD probes targeted to cellular surface receptors and measured the MFI of the resulting cell-probe conjugates by flow cytometry. MFI was converted to mean equivalent R-PE intensity (MEPE) using standard calibration microspheres. Known concentrations of both R-PE and QD probes were measured by fluorometry to relate R-PE and QD fluorescence. Fluorometry results were then used to translate MEPE measurements to the number of bound QD probes. The targeted probes exhibited superior binding characteristics over unmodified and untargeted particles. This binding interaction was shown to be specific and mediated by the NGR targeting peptide tethered to the QD surface. The calibration method developed to assess this system proved successful at converting raw fluorescence data to quantitative probe binding values. We demonstrate the synthesis and performance of a highly modular nanoparticle system capable of targeted binding and fluorescent imaging. The calibration method implemented to quantify the performance of this system represents a potentially powerful tool to utilize truly quantitative flow cytometry measurements with an array of fluorescent molecules, including QDs.

An efficient chemical approach to bispecific antibodies and antibodies of high valency

Irreversible chemical programming of monoclonal aldolase antibody (mAb) 38C2 has been accomplished with beta-lactam equipped mono- and bifunctional targeting modules, including a cyclic-RGD peptide linked to either the peptide (D-Lys(6))-LHRH or another cyclic RGD unit and a small-molecule integrin inhibitor SCS-873 conjugated to (D-Lys(6))LHRH. We also prepared monofunctional targeting modules containing either cyclic RGD or (D-Lys(6))-LHRH peptides. Binding of the chemically programmed antibodies to integrin receptors alpha(v)beta(3) and alpha(v)beta(5) and to the luteinizing hormone releasing hormone receptor were evaluated. The bifunctional and bivalent c-RGD/LHRH and SCS-783/LHRH, the monofunctional and tetravalent c-RGD/c-RGD, and the monofunctional bivalent c-RGD chemically programmed antibodies bound specifically to the isolated integrin receptor proteins as well as to integrins expressed on human melanoma M-21 cells. c-RGD/LHRH, SCS-783/LHRH, and LHRH chemically programmed antibodies bound specifically to the LHRH receptors expressed on human ovarian cancer cells. This approach provides an efficient, versatile, and economically viable route to high-valency therapeutic antibodies that target defined combinations of specific receptors. Additionally, this approach should be applicable to chemically programmed vaccines.

Effects of gonadotrophin-releasing hormone outside the hypothalamic-pituitary-reproductive axis

Gonadotrophin-releasing hormone (GnRH) is a hypothalamic decapeptide with an undisputed role as a primary regulator of gonadal function. It exerts this regulation by controlling the release of gonadotrophins. However, it is becoming apparent that GnRH may have a variety of other vital roles in normal physiology. A reconsideration of the potential widespread action that this traditional reproductive hormone exerts may lead to the generation of novel therapies and provide insight into seemingly incongruent outcomes from current treatments using GnRH analogues to combat diseases such as prostate cancer.

Contemporary epidemiology of renal cell cancer

We analyzed renal cell cancer incidence patterns in the United States and reviewed recent epidemiologic evidence with regard to environmental and host genetic determinants of renal cell cancer risk. Renal cell cancer incidence rates continued to rise among all racial/ethnic groups in the United States, across all age groups, and for all tumor sizes, with the most rapid increases for localized stage disease and small tumors. Recent cohort studies confirmed the association of smoking, excess body weight, and hypertension with an elevated risk of renal cell cancer, and suggested that these factors can be modified to reduce the risk. There is increasing evidence for an inverse association between renal cell cancer risk and physical activity and moderate intake of alcohol. Occupational exposure to trichloroethylene has been positively associated with renal cell cancer risk in several recent studies, but its link with somatic mutations of the von Hippel-Lindau gene has not been confirmed. Studies of genetic polymorphisms in relation to renal cell cancer risk have produced mixed results, but genome-wide association studies with larger sample size and a more comprehensive approach are underway. Few epidemiologic studies have evaluated risk factors by subtypes of renal cell cancer defined by somatic mutations and other tumor markers.

Synthesis, characterization and stability of a luteinizing hormone-releasing hormone (LHRH)-functionalized poly(amidoamine) dendrimer conjugate

Cancer targeting is crucial for cancer detection, therapy and targeted drug delivery. A dendrimer-peptide conjugate has been synthesized based on poly(amidoamine) dendrimer generation 5 (PAMAM G5) as a platform and a luteinizing hormone-releasing hormone (LHRH) peptide as a targeting moiety. The synthesized conjugate was fully characterized using nuclear magnetic resonance (NMR), UV-Vis spectrometry, reverse-phase high-performance liquid chromatography (RP-HPLC) and matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry. Further stability experiments showed that the synthesized conjugate was stable after 72-h incubation in phosphate-buffered saline (PBS) buffer (pH 7.4) at 37 degrees C. The synthesized conjugate may find applications in biomedical targeting, gene delivery and imaging.