Significance of heparanase-1 and vascular endothelial growth factor in adrenocortical carcinoma angiogenesis: potential for therapy

Advances in adrenocortical carcinoma pharmacotherapy: what is the current state of the art?

INTRODUCTION

Surgery, followed or not by adjuvant mitotane, is the current mainstay of therapy for patients with early-stage adrenocortical carcinoma (ACC). Mitotane, either alone or in association with EDP (Etoposide-Doxorubicin-Cisplatin) combination chemotherapy, is the standard approach for patients with metastatic ACC.

AREAS COVERED

The activity of newer cytotoxic drugs, radioligands, targeted therapies and immunotherapy, both in preclinical and in clinical studies, will be reviewed in this paper.

EXPERT OPINION

ADIUVO trial revealed that the administration of adjuvant mitotane is not advantageous in patients with good prognosis. Future strategies are to intensify efforts in adjuvant setting in patients with high risk of relapse. In patients with advanced/metastatic disease, modern targeted therapies have shown significant cytotoxicity in preclinical studies, however, studies in ACC patients reported disappointing results so far. The absence of targeted agents specifically inhibiting the major molecular pathways of ACC growth is the main cause of the failure of these drugs. Since ACC is often antigenic but poorly immunogenic, the results of immunotherapy trials appeared inferior to those achieved in the management of patients with other malignancies. Radioligand therapy may also be a promising approach. Combination of chemotherapy plus immunotherapy could be interesting to be tested in the future.

Ang-Tie Angiogenic Pathway Is Distinctively Expressed in Benign and Malignant Adrenocortical Tumors

The differential diagnosis between adrenocortical adenomas (ACAs) and adrenocortical carcinomas (ACCs) relies on unspecific clinical, imaging and histological features, and, so far, no single molecular biomarker has proved to improve diagnostic accuracy. Similarly, prognostic factors have an insufficient capacity to predict the heterogeneity of ACC clinical outcomes, which consequently lead to inadequate treatment strategies. Angiogenesis is a biological process regulated by multiple signaling pathways, including VEGF and the Ang–Tie pathway. Many studies have stressed the importance of angiogenesis in cancer development and metastasis. In the present study, we evaluated the expression of VEGF and Ang–Tie pathway mediators in adrenocortical tumors (ACTs), with the ultimate goal of assessing whether these molecules could be useful biomarkers to improve diagnostic accuracy and/or prognosis prediction in ACC. The expression of the proteins involved in angiogenesis, namely CD34, VEGF, VEGF-R2, Ang1, Ang2, Tie1 and Tie2, was assessed by immunohistochemistry in ACC (n = 22), ACA with Cushing syndrome (n = 8) and non-functioning ACA (n = 13). ACC presented a significantly higher Ang1 and Ang2 expression when compared to ACA. Tie1 expression was higher in ACC with venous invasion and in patients with shorter overall survival. In conclusion, although none of these biomarkers showed to be useful for ACT diagnosis, the Ang–Tie pathway is active in ACT and may play a role in regulating ACT angiogenesis.

Heparanase-1 is downregulated in chemoradiotherapy orbital rhabdomyosarcoma and relates with tumor growth as well as angiogenesis

AIM

To determine the role of heparanase-1 (HPSE-1) in orbital rhabdomyosarcoma (RMS), and to investigate the feasibility of HPSE-1 targeted therapy for RMS.

METHODS

Immunohistochemistry was performed to analyze HPSE-1 expression in 51 cases of orbital RMS patients (including 28 cases of embryonal RMS and 23 cases of alveolar RMS), among whom there were 27 treated and 24 untreated with preoperative chemoradiotherapy. In vitro, studies were conducted to examine the effect of HPSE-1 silencing on RMS cell proliferation and tube formation of human umbilical vein endothelial cells (HUVECs). RD cells (an RMS cell line) and HUVECs were infected with HPSE-1 shRNA lentivirus at a multiplicity of infection (MOI) of 10 and 30 separately. Real-time PCR and Western blot were applied to detect the mRNA and protein expression levels of HPSE-1. Cell viability of treated or control RD cells was evaluated by cell counting kit-8 (CCK-8) assay. Matrigel tube formation assay was used to evaluate the effect of HPSE-1 RNAi on the tube formation of HUVECs.

RESULTS

Immunohistochemistry showed that the expression rate of HPSE-1 protein was 92.9% in orbital embryonal RMS and 91.3% in orbital alveolar RMS. Tissue from alveolar orbital RMS did not show relatively stronger staining than that from the embryonal orbital RMS. However, despite the types of RMS, comparing the cases treated chemoradiotherapy with those untreated, we have observed that chemoradiotherapy resulted in weaker staining in patients' tissues. The expression levels of HPSE-1 declined significantly in both the mRNA and protein levels in HPSE-1 shRNA transfected RD cells. The CCK-8 assay showed that lentivirus-mediated HPSE-1 silencing resulted in significantly reduced RD cells viability in vitro. Silencing HPSE-1 expression also inhibited VEGF-induced tube formation of HUVECs in Matrigel.

CONCLUSION

HPSE-1 silencing may be a promising therapy for the inhibition of orbital RMS progression.

Emerging drugs for the treatment of adrenocortical carcinoma

Introduction: Adrenocortical cancer (ACC) is a rare and aggressive disease with a median survival of 14-17 months and 5-year survival of around 20% for advanced disease. Emerging evidence of sub-groups of ACC with specific molecular drivers indicate ACC may be amenable to inhibition of receptor tyrosine kinases involved in growth and angiogenic signaling. A significant subset of patients may also be responsive to immune strategies.Areas covered: This review outlines approaches of targeting upregulated growth pathways including Insulin-like Growth Factor, Vascular Endothelial Growth Factor, Fibroblast Growth Factor and Epidermal Growth Factor Receptor in ACC. Data of immune checkpoint blockade with nivolumab, ipilimumab, pembrolizumab and avelumab is explored in detail. Genomic studies indicate that up to 40% of ACC are driven by dysregulated WNT and glucocorticoid signaling, special focus is placed on emerging drugs in these pathways.Expert opinion: Progress in the treatment of ACC has faced challenges stemming from the rarity of the disease. Given recent advances in the understanding of the molecular pathogenesis of ACC, a window of opportunity has now opened to make significant progress in developing therapeutic options that target key pathways such as excessive glucocorticoid signaling, WNT signaling, cell cycle and immune checkpoints.

Angiogenesis in the Normal Adrenal Fetal Cortex and Adrenocortical Tumors

Angiogenesis plays an important role in several physiological and pathological processes. Pharmacological angiogenesis modulation has been robustly demonstrated to achieve clinical benefits in several cancers. Adrenocortical carcinomas (ACC) are rare tumors that often have a poor prognosis. In addition, therapeutic options for ACC are limited. Understanding the mechanisms that regulate adrenocortical angiogenesis along the embryonic development and in ACC could provide important clues on how these processes could be pharmacologically modulated for ACC treatment. In this report, we performed an integrative review on adrenal cortex angiogenesis regulation in physiological conditions and ACC. During embryonic development, adrenal angiogenesis is regulated by both VEGF and Ang-Tie signaling pathways. In ACC, early research efforts were focused on VEGF signaling and this pathway was identified as a good prognostic factor and thus a promising therapeutic target. However, every clinical trial so far conducted in ACC using VEGF pathway- targeting drugs, alone or in combination, yielded disappointing results. In contrast, although the Ang-Tie pathway has been pointed out as an important regulator of fetal adrenocortical angiogenesis, its role is yet to be explored in ACC. In the future, further research on the role and efficacy of modulating both Ang-Tie and VEGF pathways in ACC is needed.

Adrenocortical Carcinoma Steroid Profiles: In Silico Pan-Cancer Analysis of TCGA Data Uncovers Immunotherapy Targets for Potential Improved Outcomes

Despite progress in understanding the biology of adrenocortical carcinoma (ACC), treatment options have not dramatically changed in the last three decades, nor have we learned how to avoid some of its long-term side effects. Our goal was to improve the understanding of immune pathways that may include druggable targets to enhance immune responses of patients with ACC, focusing on immune evasion and the activation of immune cells against ACC. Our strategy was aimed at improving insight regarding gene expression without steroid interference. Using approaches based on high and low steroid phenotypes (HSP and LSP, respectively), we characterized immune pathways using The Cancer Genome Atlas (TCGA) ACC cohort data. Although previous studies have suggested that patients with ACC receive minimal benefit from immunotherapy, high expression of immune modulators was noted in patients with LSP, suggesting the activation of these biomarkers may be an important adjuvant therapy target after clearance of excess glucocorticoids. In addition, patients with LSP ACC had higher immune cell infiltration than patients with HSP ACC and other cancer subtypes. Our findings can be summarized as follows (1): we confirmed and improved the definition of two immune response pathways to ACC (HSP and LSP) based on in silico transcriptome analysis (2), we demonstrated the steroid profile should be considered, otherwise analyses of ACC immune characteristics can generate confounding results (3), among the overexpressed immunotherapy targets, we demonstrated that LSP was rich in PDCD1LG2 (PD-L2) and both HSP and LSP overexpressed CD276 (B7-H3), which was associated with resistance to anti-PD1 therapy and may have accounted for the modest results of previous clinical trials, and (4) identification of patients with LSP or HSP ACC can be used to help determine whether immunotherapy should be used. In conclusion, we highlighted the differences between LSP and HSP, drawing attention to potential therapeutic targets (CD276, PDCD1, and PDCD1LG2). Treatments to reduce immune evasion, as well as the use of other natural and pharmacological immune activators, should include prior pharmacological inhibition of steroidogenesis. Attempts to combine these with tumor cell proliferation inhibitors, if they do not affect cells of the immune system, may produce interesting results.

Role of FGF Receptors and Their Pathways in Adrenocortical Tumors and Possible Therapeutic Implications

Adrenocortical carcinoma (ACC) is a rare endocrine malignancy and treatment of advanced disease is challenging. Clinical trials with multi-tyrosine kinase inhibitors in the past have yielded disappointing results. Here, we investigated fibroblast growth factor (FGF) receptors and their pathways in adrenocortical tumors as potential treatment targets. We performed real-time RT-PCR of 93 FGF pathway related genes in a cohort of 39 fresh frozen benign and malignant adrenocortical, 9 non-adrenal tissues and 4 cell lines. The expression of FGF receptors was validated in 166 formalin-fixed paraffin embedded (FFPE) tissues using RNA in situ hybridization (RNAscope) and correlated with clinical data. In malignant compared to benign adrenal tumors, we found significant differences in the expression of 16/94 FGF receptor pathway related genes. Genes involved in tissue differentiation and metastatic spread through epithelial to mesechymal transition were most strongly altered. The therapeutically targetable FGF receptors 1 and 4 were upregulated 4.6- and 6-fold, respectively, in malignant compared to benign adrenocortical tumors, which was confirmed by RNAscope in FFPE samples. High expression of FGFR1 and 4 was significantly associated with worse patient prognosis in univariate analysis. After multivariate adjustment for the known prognostic factors Ki-67 and ENSAT tumor stage, FGFR1 remained significantly associated with recurrence-free survival (HR=6.10, 95%CI: 1.78 - 20.86, p=0.004) and FGFR4 with overall survival (HR=3.23, 95%CI: 1.52 - 6.88, p=0.002). Collectively, our study supports a role of FGF pathways in malignant adrenocortical tumors. Quantification of FGF receptors may enable a stratification of ACC for the use of FGFR inhibitors in future clinical trials.

Refractory shock during the anesthetic and surgical management of an intrahepatic tumor arising from the adrenal cortex: A case report

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With adrenocortical carcinoma, tumoral secretion is present in 25 to 75% of the cases.

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In the absence of excessive hormonal production, the diagnosis is often delayed.

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Isolated liver metastatic lesion may develop after several years of follow-up.

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Resection of a large intrahepatic malignant lesion may be complicated by a secondary capillary leak syndrome.

Introduction

Adrenocortical carcinoma is a rare type of malignant adrenal tumor with a possibility of delayed metastases. Diagnosis may be delayed with a non-secreting tumor or metastasis, and even in this case, surgical management may be complicate.

Presentation of case

A 55-year-old man underwent elective surgery for the resection of a large intra-hepatic mass from an undetermined type according to a recent liver biopsy. He had a previous history of a non-secreting adrenal tumor that was operated ten years before. Pre-operatively, he was poorly symptomatic, with a normal arterial blood pressure. Anesthesia induction was uneventful, but at the time of tumor resection and removal, he developed extreme vasoplegia and shock with anuric renal failure, lactic acidosis, four-limb and abdominal compartment syndrome. The patient died on day 9 from delayed septic complications. According to the pathological findings, the tumor was a non-secreting adrenocortical carcinoma.

Discussion

Adrenocortical carcinoma (ACC) is rare condition with diverse clinical manifestations due to excessive hormonal production when the tumor is secreting and mimicking pheochromocytoma. Our patient underwent the resection a large intrahepatic non-secreting metastasis more than ten years after the initial lesion. Peri-operative and post-operative management was complicated by a refractory shock with the characteristics of a secondary systemic capillary leak syndrome. The role of endothelial lesions may be discussed.

Conclusion

Surgery of metastatic adrenocortical carcinoma may be complicated by severe hemodynamic complications, even in the absence of hormonal secretion.

SIRT6 abrogation promotes adrenocortical carcinoma through activation of NF-κB signaling

As an uncommon malignancy in the adrenal gland, adrenocortical carcinoma (ACC) is characterized by thorny diagnosis and poor clinical outcome, necessitating innovative treatment strategies. Sirtuin 6 (SIRT6), a tumor suppressor, modulates aerobic glycolysis of malignant cells and has an impact on tumorigenesis. This study focused on investigating SIRT6 expression in ACC and how it generates cancer phenotypes. SIRT6 expression was inhibited in ACC tissues according to western blotting, real-time polymerase chain reaction, and immunohistochemistry. MTT assay, TUNEL assay, and flow cytometry were performed to evaluate the contribution of SIRT6 to cell invasion, proliferation, death, and migration. It was shown that SIRT6 knockdown promoted cell invasion, proliferation, and migration, and inhibited cell death. Moreover, it was found that SIRT6 knockdown upregulated TLR4 and reinforced phosphorylation of the nuclear transcription factor-kappa B (NF-κB) subunit p65 as well as inhibitor of nuclear factor kappa-B kinase. Additionally, SIRT6 knockdown significantly enhanced expression of calcitonin gene-related peptide as well as transient receptor potential vanilloid subtype 1. It also reinforced reactive oxygen species generation. Overall, our research findings demonstrate that SIRT6 serves as a tumor suppressor via regulation of the NF-κB pathway, which could offer an innovative strategy to treat ACC.

Management of Adrenocortical Carcinoma

PURPOSE OF REVIEW

Adrenocortical carcinoma (ACC) is a rare endocrine malignancy typically with poor prognosis. This review aims to summarize the current knowledge regarding the clinical management of ACC.

RECENT FINDINGS

Surgery remains the cornerstone for localized ACC management. In more advanced cases, debulking surgery when feasible can help with hormonal control and may allow the initiation of systemic therapy. Over the last few years, our understanding of ACC molecular pathogenesis has expanded with no significant change in treatment options. Platinum-based chemotherapy is the gold standard in metastatic ACC despite suboptimal efficacy. Tyrosine kinase inhibitor use did not result in meaningful benefit in ACC patients. Multiple clinical trials are currently exploring the role of immunotherapy in ACC. Despite the remarkable improvement in our understanding of the molecular signature and pathways in ACC, this knowledge did not yield a major breakthrough in management of advanced ACC. Multi-institutional and international collaborations are needed to identify promising treatments and new therapeutic targets to improve the care of ACC patients.

Diagnostic Role of Prostate-Specific Membrane Antigen in Adrenocortical Carcinoma

Objective: To investigate the role of PSMA in the differential diagnosis of adrenocortical carcinoma samples (ACCs) and adrenocortical adenoma samples (ACAs), to validate the prognostic role of PSMA in patients with ACCs, and to explore the possibility that this marker can differentiate localized ACCs from adrenal metastases from other sites. Methods: PSMA protein expression in tissue samples from 50 ACCs, 90 ACAs (including 20 from patients who presented with Cushing's syndrome, 20 aldosterone-producing adenomas and 50 non-functional tumors) and 10 tissues that were metastases from other primary sites was assessed by immunohistochemistry. The clinical and pathological characteristics were compared, the intensity and density were analyzed, and the prognostic role was evaluated. Results: The analysis of clinical and pathological features revealed that the size of ACCs was greater than that of benign tissues and the ACC patients were older than the ACA patients (p < 0.01). The percentage of PSMA-positive vessels, the mean intensity and the degree of staining density were found to be significantly lower in ACAs than in ACCs (p < 0.01). In these 140 samples, 60% of the ACCs were grouped in the positive category. The samples were negative for metastases that were from other primary sites. The ENSAT stage and Ki-67 were correlated with PSMA expression. The survival distribution revealed that high PSMA expression did not show any prognostic relevance in the current ACCs series. Those samples with a score of > 3.5 were 75 times more likely to be malignant (OR = 75). We established a cut-off score of 3.5 (p < 0.05), which had 46% sensitivity and 99% specificity. Paralleling PSMA and Ki-67 maximized the area under the curve, with 72% sensitivity and 100% specificity. Conclusions: Our results strongly confirm that PSMA is helpful for distinguishing benign from malignant tumors and that its high expression levels correlate with a high ENSAT stage and high proliferation. The combination of PSMA and Ki-67 can be particularly useful. Furthermore, PSMA might be a useful tool for the identification of localized adrenal carcinoma and metastatic carcinoma.

The tyrosine kinase inhibitor nilotinib is more efficient than mitotane in decreasing cell viability in spheroids prepared from adrenocortical carcinoma cells

Background

New drugs for adrenocortical carcinoma (ACC) are needed because most patients undergo rapid disease progression despite surgery and adjuvant therapy with mitotane. In this study, we aimed to investigate the in vitro effects of different chemotherapy drugs, alone or combined with mitotane, on the viability of adrenocortical carcinoma cells.

Methods

Everolimus, sunitinib, zoledronic acid, imatinib and nilotinib cytotoxicity, alone or combined with mitotane were tested on ACC H295R cells in monolayer or spheroid cultures using MTS assays and confocal microscopy. Moreover, the nilotinib effects were investigated in spheroids cultured from patient tumor-derived ACC-T36 cells.

Results

Morphological characterization of H295R cell spheroids using histochemistry was performed and showed that dense, homogenously sized, multicellular spheroids were obtained. We observed that sunitinib and nilotinib alone were equally effective in a monolayer preparation, whereas mitotane was the most effective even at a low dose. A combination of sunitinib and mitotane was the most effective treatment, with only 23.8% of cells in the monolayer remaining viable. Spheroid preparations showed resistance to different drugs, although the poor effect produced by mitotane alone was surprising, with a cell viability of 84.6% in comparison with 13.1% in monolayer cells. The most ineffective drugs in spheroid preparations were everolimus, zoledronic acid and imatinib. In both cell types, nilotinib, either alone or in combination with mitotane induced more significant cell viability inhibition in monolayer and spheroid preparations. In addition, the mechanism of nilotinib activity involves the ERK1/2 pathway.

Conclusion

Taken together, our data identified nilotinib as a cytotoxic drug that combined with ERK inhibitors deserves to be tested as a novel therapy for adrenocortical carcinoma.

The challenge of developmental therapeutics for adrenocortical carcinoma

Adrenocortical carcinoma (ACC) is a rare disease with an estimated incidence of only 0.7 new cases per million per year. Approximately 30-70% of the patients present with advanced disease with very poor prognosis and without effective therapeutic options. In the recent years, unprecedented progresses in cancer biology and genomics have fostered the development of numerous targeted therapies for various malignancies. Immunotherapy has also transformed the treatment landscape of malignancies such as melanoma, among others. However, these advances have not brought meaningful benefits for patients with ACC. Extensive genomic analyses of ACC have revealed numerous signal transduction pathway aberrations (e.g., insulin growth factor receptor and Wnt/β-catenin pathways) that play a central role in pathophysiology. These molecular alterations have been explored as potential therapeutic targets for drug development. This manuscript summarizes recent discoveries in ACC biology, reviews the results of early clinical studies with targeted therapies, and provides the rationale for emerging treatment strategies such as immunotherapy.

Development of biocompatible and VEGF-targeted paclitaxel nanodrugs on albumin and graphene oxide dual-carrier for photothermal-triggered drug delivery in vitro and in vivo

In this study, we performed the characterization and synthesis of biocompatible and targeted albumin and graphene oxide (GO) dual-carrier paclitaxel (PTX) nanoparticles for photothermal-triggered tumor therapy. PTX absorbed on GO nanosheets as cores were coated with human serum albumin (HSA), following surface conjugation with monoclonal antibodies (mAb) against vascular endothelial growth factor (VEGF; denoted as mAbVEGF) via polyethylene glycol linker to form targeted nanoparticles (PTX-GHP-VEGF). The spherical nanoparticles were 191±5 nm in size with good stability and biocompatibility. GO functioned as the first carrier and a near infrared absorber that can generate photothermal effects under 5-minute 808-nm laser irradiation to thermal trigger the release of PTX from the second carrier HSA nanoparticles. The mechanism of thermal-triggered drug release was also investigated preliminarily, in which the heat generated by GO induced swelling of PTX-GHP-VEGF nanoparticles which released the drugs. In vitro studies found that PTX-GHP-VEGF can efficiently target human SW-13 adrenocortical carcinoma cells as evaluated by confocal fluorescence microscopy as well as transmission electron microscopy, and showed an obvious thermal-triggered antitumor effect, mediated by apoptosis. Moreover, PTX-GHP-VEGF combined with near infrared irradiation showed specific tumor suppression effects with high survival rate after 100 days of treatment. PTX-GHP-VEGF also demonstrated high biosafety with no adverse effects on normal tissues and organs. These results highlight the remarkable potential of PTX-GHP-VEGF in photothermal controllable tumor treatment.

Molecular targeted therapies in adrenal, pituitary and parathyroid malignancies

Tumourigenesis is a relatively common event in endocrine tissues. Currently, specific guidelines have been developed for common malignant endocrine tumours, which also incorporate advances in molecular targeted therapies (MTT), as in thyroid cancer and in gastrointestinal neuroendocrine malignancies. However, there is little information regarding the role and efficacy of MTT in the relatively rare malignant endocrine tumours mainly involving the adrenal medulla, adrenal cortex, pituitary, and parathyroid glands. Due to the rarity of these tumours and the lack of prospective studies, current guidelines are mostly based on retrospective data derived from surgical, locoregional and ablative therapies, and studies with systemic chemotherapy. In addition, in many of these malignancies the prognosis remains poor with individual patients responding differently to currently available treatments, necessitating the development of new personalised therapeutic strategies. Recently, major advances in the molecular understanding of endocrine tumours based on genomic, epigenomic, and transcriptome analysis have emerged, resulting in new insights into their pathogenesis and molecular pathology. This in turn has led to the use of novel MTTs in increasing numbers of patients. In this review, we aim to present currently existing and evolving data using MTT in the treatment of adrenal, pituitary and malignant parathyroid tumours, and explore the current utility and effectiveness of such therapies and their future evolution.

Update on adrenocortical carcinoma management and future directions

PURPOSE OF REVIEW

To present an update on the management of and future directions in adrenocortical carcinoma (ACC).

RECENT FINDINGS

ACC is a rare malignancy with high morbidity and mortality. Surgery remains the mainstay treatment for localized disease, but it is often not feasible in more advanced cases. There is an ongoing controversy about the routine use of adjuvant treatments after surgery. Hormonal overproduction can complicate the management and worsen the prognosis of the disease. Systemic therapy with multiple cytotoxic drugs is often combined with the adrenolytic agent mitotane. Genomic analyses of ACC revealed numerous signal transduction pathway aberrations (insulin-like growth factor 2 overexpression, TP53 mutations and Wnt/β-catenin pathway activation), but so far, there has been no clinically meaningful breakthrough in targeting these genes. Immunotherapy offers hope for altering the orthodox management of cancer, and its role in ACC is being explored in multiple ongoing trials.

SUMMARY

Surgery by experienced team is the key treatment for localized ACC, whereas currently used chemotherapy has limited efficacy in advanced ACC. The improved understanding of the molecular pathways involved in ACC has not been translated into effective therapy. The development of new therapies requires collaborative effort to fight this disease.

New insights and future perspectives in the therapeutic strategy of adrenocortical carcinoma (Review)

Adrenocortical carcinoma (ACC) is a rare endocrine malignancy with an incidence ranging from 0.7 to 2.0 cases/million people per year. Hypercortisolism represents the most common clinical presentation in many patients although, less frequently, some ACC secreting androgens and estrogens are even more pathognomonic compared to cortisol secretion. Currently, radical surgery, when feasible, is still the only curative therapy. Mitotane, an adrenolytic drug, is used in the adjuvant setting and in combination with chemotherapy drugs in metastatic disease. The use of radiotherapy remains controversial, being indicated only in selected cases. New targeted therapies, such as insulin growth factor-1 (IGF-1), mammalian-target of rapamycin (m-TOR), vascular endothelial growth factor (VEGF) inhibitors and others, have recently been investigated with disappointing clinical results. The partial effectiveness of current treatments mandates the need for new therapeutic strategies against this tumor.

Novel targeted therapies in adrenocortical carcinoma

PURPOSE OF REVIEW

Adrenocortical carcinoma is a rare cancer, but one that carries a poor prognosis due to its aggressive nature and unresponsiveness to conventional chemotherapeutic strategies. Over the past 12 years, there has been renewed interest in developing new therapies for this cancer, including identifying key signaling nodes responsible for cell proliferation.

RECENT FINDINGS

Clinical trials of tyrosine kinase inhibitors as monotherapy have generally been disappointing, although the identification of exceptional responders may lead to the identification of targeted therapies that may produce responses in subsets of patients. Agents targeted to the Wnt signaling pathway, a known player in adrenal carcinogenesis, have been developed, although they have not yet been used specifically for adrenal cancer. There is current excitement about inhibitors of acetyl-coA cholesterol acetyl transferase 1, an enzyme required for intracellular cholesterol handling, although trials are still underway. Tools to target other proteins such as Steroidogenic Factor 1 and mechanistic target of rapamycin have been developed and are moving towards clinical application.

SUMMARY

Progress is being made in the fight against adrenocortical carcinoma with the identification of new therapeutic targets and new means by which to attack them. Continued improvement in the prognosis for patients with adrenal cancer is expected as this research continues.

Vasculogenic mimicry plays an important role in adrenocortical carcinoma

OBJECTIVES

To determine the prognostic role of vasculogenic mimicry in adrenocortical carcinoma, and to explore its relationship with vascular endothelial growth factor receptor 2 expression.

METHODS

A total of 46 samples of adrenocortical carcinoma were collected and reviewed. Vasculogenic mimicry and vascular endothelial growth factor receptor 2 were detected by immunohistochemistry and double staining. Survival analysis was carried out to access pronostic significance. Three-dimensional culture method was applied to test the ability of vasculogenic mimicry formation by adrenocortical carcinoma cell lines SW-13 and H295R. Quantitative polymerase chain reaction and western blotting were used to monitor the expression of vascular endothelial growth factor receptor 2 in SW-13 and H295R. After being treated with specific inhibitor or small interfering ribonucleic acid to downregulate expression of vascular endothelial growth factor receptor 2, vasculogenic mimicry formation and cell prolifration of SW-13 cells were evaluated by 3-D culture and Cell Counting Kit-8 methods.

RESULTS

Vasculogenic mimicry was observed in 19 of the 46 (41.30%) adrenocortical carcinoma samples. Both vasculogenic mimicry and vascular endothelial growth factor receptor 2 expressions showed a positive association with Weiss score and TNM stage, whereas vascular endothelial growth factor receptor 2 was also associated with tumor size (all P < 0.05). Vasculogenic mimicry was closely correlated with vascular endothelial growth factor receptor 2 expressions (r = 0.470, P < 0.01). The median overall survival of patients with vasculogenicmimicry-positive or vascular endothelial growth factor receptor 2-positive was shorter than that of patients with vasculogenic mimicry-negative or vascular endothelial growth factor receptor 2-negative (P = 0.001 and 0.028, respectively). The vasculogenic mimicry-forming SW-13 cells expressed higher levels of vascular endothelial growth factor receptor 2 than that of H295R, which was unable to form vasculogenic mimicry on Matrigel. However, downregulation of vascular endothelial growth factor receptor 2 only decreased cell proliferation, but not vasculogenic mimicry formation by SW-13 cells.

CONCLUSIONS

Vasculogenic mimicry and overexpression of vascular endothelial growth factor receptor 2 seem to correlate with poor prognostic outcomes in adrenocortical carcinoma. Anti-angiogenesis treatments targeting vascular endothelial growth factor receptor 2 should be combined with therapies targeting vasculogenic mimicry in adrenocortical carcinoma.

Role of the novel HSP90 inhibitor AUY922 in hepatocellular carcinoma: Potential for therapy

The aim of the present study was to determine the correlation between hepatocellular carcinoma (HCC) and heat shock protein 90 (HSP90), involved in tumor angiogenesis, and to evaluate the effect of AUY922, a HSP90 inhibitor, in HCC. The expression of HSP90 and microvessel density (MVD) were measured in tissue samples from 76 patients with HCC by immunohistochemistry. Western blot analysis was performed to detect the expression of HSP90 in the HCC tissues and different HCC cell lines. The effects of time and concentration treatment with the AUY922 HSP90 inhibitor were investigated in HepG2 cells. Cell proliferation was measured using an MTT assay and a Transwell assay was performed to evaluate the migration of the HepG2 cells following treatment with different concentrations of AUY922. Positive staining of HSP90 was observed in 88.16% (67/76) of the HCC tissues, compared with 16.67% (4/24) of the normal tissues. The difference in the expression of HSP90 between the HCC and normal tissues was statistically significant (P<0.001). Tumors exhibiting positive expression of HSP90 had significantly higher MVD compared with the HSP90-negative counterparts (82.8 ± 12.44 vs. 23.8 ± 8.07, respectively; P<0.001). The expression levels of HSP90 were positively correlated with MVD in all the tissue samples (r_s=0.724; P<0.001). AUY922 inhibited the proliferation of the HepG2 cells in a time-and concentration-dependent manner, and the migration of HepG2 cells was distinctly suppressed following treatment with AUY922. These data suggested that the angiogenesis of human HCC may be mediated by HSP90, and that the specific HSP90 inhibitor, AUY922, has a therapeutic role in the treatment of HCC. Therefore, HSP90 may represent a selective target in molecularly targeted treatment of HCC.

EJE prize 2014: current and evolving treatment options in adrenocortical carcinoma: where do we stand and where do we want to go?

Adrenocortical carcinoma (ACC) is not only a rare and heterogeneous disease but also one of the most aggressive endocrine tumors. Despite significant advances in the last decade, its pathogenesis is still only incompletely understood and overall therapeutic means are unsatisfactory. Herein, we provide our personal view of the currently available treatment options and suggest the following research efforts that we consider timely and necessary to improve therapy: i) for better outcome in localized ACCs, surgery should be restricted to experienced centers, which should then collaborate closely to address the key surgical questions (e.g. best approach and extent of surgery) in a multicenter manner. ii) For the development of better systemic therapies, it is crucial to elucidate the exact molecular mechanisms of action of mitotane. iii) A prospective trial is needed to address the role of cytotoxic drugs in the adjuvant setting in aggressive ACCs (e.g. mitotane vs mitotane+cisplatin). iv) For metastatic ACCs, new regimens should be investigated as first-line therapy. v) Several other issues (e.g. the role of radiotherapy and salvage therapies) might be answered - at least in a first step - by large retrospective multicenter studies. In conclusion, although it is unrealistic to expect that the majority of ACCs can be cured within the next decade, international collaborative efforts (including multiple translational and clinical studies) should allow significant improvement of clinical outcome of this disease. To this end, it might be reasonable to expand the European Network for the Study of Adrenal Tumors (ENSAT) to a truly worldwide international network - INSAT.

The VEGF inhibitor axitinib has limited effectiveness as a therapy for adrenocortical cancer

CONTEXT

Adrenocortical carcinoma (ACC) is a rare malignancy with a poor prognosis in need of more effective treatment options. Published evidence indicates many ACCs express the vascular endothelial growth factor receptor (VEGFR), suggesting inhibiting vascular endothelial growth factor signaling could potentially impact tumor growth.

OBJECTIVE

The objective of the study was to determine the antitumor efficacy of axitinib (AG-013736), a potent, selective inhibitor of VEGFR1, -2, and -3.

DESIGN

This was a phase II, open-label trial using a two-stage design.

PATIENTS

Thirteen patients with metastatic ACC previously treated with at least one chemotherapy regimen with or without mitotane participated in the study.

INTERVENTION

Starting axitinib dose was 5 mg orally twice daily. Dose escalations were permitted if the administered dose was tolerable.

RESULTS

Thirteen patients were enrolled. Dose escalation was possible in seven patients, but the majority could not tolerate a dose higher than the starting 5 mg, twice-daily dose for prolonged periods of time. All patients experienced known grade 1/2 toxicities, and 10 of 13 patients had at least one grade 3/4 adverse event. No patient tumor could be scored as a Response Evaluation Criteria in Solid Tumors response, although the growth rate on therapy compared with that prior to starting axitinib was reduced in 4 of the 13 patients. The median progression-free survival was 5.48 months, and the median overall survival was longer than 13.7 months.

CONCLUSION

Axitinib has limited effectiveness in ACC. Together with 48 patients previously reported who received either sorafenib or sunitinib, a total of 61 ACC patients have now been treated with a VEGFR tyrosine kinase inhibitor without an objective Response Evaluation Criteria in Solid Tumors response. Future trials in ACC should look to other targets for possible active agents.

Molecular markers and targeted therapies for adrenocortical carcinoma

Adrenocortical carcinoma (ACC) is a lethal disease with poor prognosis and lack of effective therapeutic options. Systemic treatment is often employed to treat patients with advanced ACC, but outcomes are disappointing. During the last decade, some of the causative genetic mutations in sporadic ACCs have been identified. Molecular analysis has had a significant impact on the understanding of the pathogenetic mechanism of ACC development and the evaluation of prognostic and predictive markers. Preclinical investigations and clinical trials of tyrosine kinase inhibitors and anti-angiogenic compounds have been initiated to seek target therapy of ACCs. This review summarizes the current view of molecular alterations involved in the pathophysiology of adrenocortical carcinogenesis. The rationale for testing targeted therapies of ACC is also presented.

Update in adrenocortical carcinoma

Adrenocortical carcinoma (ACC) is an orphan malignancy that has attracted increasing attention during the last decade. Here we provide an update on advances in the field since our last review published in this journal in 2006. The Wnt/β-catenin pathway and IGF-2 signaling have been confirmed as frequently altered signaling pathways in ACC, but recent data suggest that they are probably not sufficient for malignant transformation. Thus, major players in the pathogenesis are still unknown. For diagnostic workup, comprehensive hormonal assessment and detailed imaging are required because in most ACCs, evidence for autonomous steroid secretion can be found and computed tomography or magnetic resonance imaging (if necessary, combined with functional imaging) can differentiate benign from malignant adrenocortical tumors. Surgery is potentially curative in localized tumors. Thus, we recommend a complete resection including lymphadenectomy by an expert surgeon. The pathology report should demonstrate the adrenocortical origin of the lesion (eg, by steroidogenic factor 1 staining) and provide Weiss score, resection status, and quantitation of the proliferation marker Ki67 to guide further treatment. Even after complete surgery, recurrence is frequent and adjuvant mitotane treatment improves outcome, but uncertainty exists as to whether all patients benefit from this therapy. In advanced ACC, mitotane is still the standard of care. Based on the FIRM-ACT trial, mitotane plus etoposide, doxorubicin, and cisplatin is now the established first-line cytotoxic therapy. However, most patients will experience progress and require salvage therapies. Thus, new treatment concepts are urgently needed. The ongoing international efforts including comprehensive "-omic approaches" and next-generation sequencing will improve our understanding of the pathogenesis and hopefully lead to better therapies.

Expression of STAT3 and IGF2 in adrenocortical carcinoma and its relationship with angiogenesis

OBJECTIVE

The aim of this study was to determine the correlation between human adrenocortical carcinoma and the proteins involved in tumor angiogenesis, and to evaluate the angiogenic status of adrenocortical carcinoma.

METHODS

The expression of signal transducer and activator of transcription 3 and insulin-like growth factor 2 as well as microvessel density was measured in a series of tissue samples from 44 human sporadic adrenocortical tumors by immunohistochemistry. These specimens were classified as adenomas (n = 20) and carcinomas (n = 24) according to the histological criteria defined by Weiss.

RESULTS

A total of 19 of 24 (79.17 %) malignant cases showed positive staining for signal transducer and activator of transcription 3 and 4 of 20 (20.00 %) benign cases showed positive, the difference of signal transducer and activator of transcription 3 expression between adrenocortical adenomas and adrenocortical carcinomas was statistically significant (P < 0.001). Similarly, insulin-like growth factor 2 staining was seen in 70.83 % (17/24) of the malignant cases versus 25.00 % (5/20) of the benign, the difference of insulin-like growth factor 2 expression among two groups was statistically significant (P = 0.002). Malignant cases showed higher microvessel density compared to benign tumors (84.70 ± 12.44 vs 21.05 ± 8.07, P < 0.001). Signal transducer and activator of transcription 3 and insulin-like growth factor 2 expression were positively correlated with microvessel density in all specimens (r_s = 0.832, P < 0.001; r_s = 0.703, P = 0.001).

CONCLUSIONS

This study has confirmed that adrenocortical carcinoma overexpress signal transducer and activator of transcription 3 and insulin-like growth factor 2; these results suggest that angiogenesis of human adrenocortical carcinoma may be mediated by these proteins and they could represent selective targets for the molecularly targeted treatments of adrenocortical carcinoma.

Suppression of endoplasmic reticulum stress-induced invasion and migration of breast cancer cells through the downregulation of heparanase

Tumor metastasis is the ultimate stage of cancer, and the primary cause of mortality in patients. Tumor cells breaking through the natural barrier consisting of the basement membrane (BM) and extracellular matrix (ECM) is the a crucial step in tumor invasion and metastasis. Thus, protecting this barrier is the key to reducing mortality. Heparanase is a mammalian endo-β-glucuronidase which has been found to promote the cleavage of heparan sulfate (HS), and plays a significant role in tumor cell invasion and metastasis. Although chemotherapeutic reagents have a strong antitumor activity, they may promote the invasion and migration of cancer cells, as has been observed during clinical treatment. Chemotherapeutic reagents can induce endoplasmic reticulum (ER) stress; in this study, we used adriamycin (ADM) and a classical ER stress inducer, tunicamycin (TM). We report that the activation of ER stress is involved in the enhanced invasion and migration ability of breast cancer cells and we hypothesized that this effect is associated with the activation of heparanase. In support of this, we used the heparanase inhibitor, OGT2115, and low molecular weight heparin (LMWH) to inhibit the expression and activity of heparanase, and we found that the invasion and migration ability of the cells was suppressed. Our findings demonstrate that heparanase inhibitors suppress breast cancer cell invasion and migration induced by ER stress, and provide a strong rationale for the development of heparanase-based therapeutics for the prevention of metastasis induced by chemotherapeutic reagents.

Synthesized multiple antigenic polypeptide vaccine based on B-cell epitopes of human heparanase could elicit a potent antimetastatic effect on human hepatocellular carcinoma in vivo

Aims

The aim of this study was to investigate the antimetastatic effect of multiple antigenic polypeptide (MAP) vaccine based on B-cell epitopes of heparanase (HPSE) on human hepatocellular carcinoma (HCC) in vivo.

Methods

The antiserum against B-cell epitopes of HPSE was isolated, purified and characterized after immunizing white-hair-black-eye (WHBY) rabbit with freshly synthesized MAP vaccine. Tumor-bearing murine models of orthotopic implants using HCC-97H cell line were built in BALB/c nude mice. Anti-MAP polyclonal antibodies induced by MAP vaccine were administrated to the models. The impact on metastasis was assessed, the expressions of VEGF/bFGF in hepatoma tissues and in murine sera were evaluated, and the micro-vessel density (MVD) was counted as well. In addition, the possible impairments of the HPSE MAP vaccine on certain HPSE positive normal organs and blood cells were investigated.

Results

The antiserum was harvested, purified and identified. The antibodies induced by MAP vaccine could specifically react with the dominant epitopes of both precursor protein and large subunit monomer of HPSE, markedly decrease HPSE activity, suppress the expressions of both VEGF and bFGF, and reduce the MVD. Pulmonary metastasis was also attenuated significantly by the anti-MAP polyclonal antibodies. In addition, no obvious impairment could be observed in certain HPSE positive organs and cells.

Conclusion

MAP vaccine based on B-cell epitopes of HPSE is capable of alleviating HCC metastasis in vivo, mainly through inhibiting the HPSE activity and tumor associated angiogenesis, by virtue of the specific anti-MAP polyclonal antibodies. Furthermore, these HPSE-specific antibodies do not cause obvious abnormalities on certain HPSE positive blood cells and organs. Our study provides theoretical evidences for the clinical use of the synthesized MAP vaccine based on B-cell epitopes of HPSE in preventing HCC metastasis.

Management of adjuvant mitotane therapy following resection of adrenal cancer

Whenever adrenal cancer (ACC) is completely removed we should face the dilemma to treat by means of adjuvant therapy or not. In our opinion, adjuvant mitotane is the preferable approach in most cases because the majority of patients following radical removal of an ACC have an elevated risk of recurrence. A better understanding of factors that influence prognosis and response to treatment will help in stratifying patients according to their probability of benefiting from adjuvant mitotane, with the aim of sparing unnecessary toxicity to patients who are likely unresponsive. However, until significant advancements take place, we have to deal with uncertainty using our best clinical judgement and personal experience in the clinical decision process. In the present paper, we present the current evidence on adjuvant mitotane treatment and describe the management strategies of patients with ACC after complete surgical resection. We acknowledge the limit that most recommendations are based on personal experience rather than solid evidence.

Current and emerging therapeutic options in adrenocortical cancer treatment

Adrenocortical carcinoma (ACC) is a very rare endocrine tumour, with variable prognosis, depending on tumour stage and time of diagnosis. The overall survival is five years from detection. Radical surgery is considered the therapy of choice in the first stages of ACC. However postoperative disease-free survival at 5 years is only around 30% and recurrence rates are frequent. o,p'DDD (ortho-, para'-, dichloro-, diphenyl-, dichloroethane, or mitotane), an adrenolytic drug with significant toxicity and unpredictable therapeutic response, is used in the treatment of ACC. Unfortunately, treatment for this aggressive cancer is still ineffective. Over the past years, the growing interest in ACC has contributed to the development of therapeutic strategies in order to contrast the neoplastic spread. In this paper we discuss the most promising therapies which can be used in this endocrine neoplasia.

Combination of sorafenib and everolimus impacts therapeutically on adrenocortical tumor models

Treatment options are insufficient in patients with adrenocortical carcinoma (ACC). Based on the efficacy of sorafenib, a tyrosine kinase inhibitor, and everolimus, an inhibitor of the mammalian target of rapamycin in tumors of different histotype, we aimed at testing these drugs in adrenocortical cancer models. The expression of vascular endothelial growth factor and its receptors (VEGFR1-2) was studied in 18 ACCs, 33 aldosterone-producing adenomas, 12 cortisol-producing adenomas, and six normal adrenal cortex by real-time PCR and immunohistochemistry and by immunoblotting in SW13 and H295R cancer cell lines. The effects of sorafenib and everolimus, alone or in combination, were tested on primary adrenocortical cultures and SW13 and H295R cells by evaluating cell viability and apoptosis in vitro and tumor growth inhibition of tumor cell line xenografts in immunodeficient mice in vivo. VEGF and VEGFR1-2 were detected in all samples and appeared over-expressed in two-thirds of ACC specimens. Dose-dependent inhibition of cell viability was observed particularly in SW13 cells after 24 h treatment with either drug; drug combination produced markedly synergistic growth inhibition. Increasing apoptosis was observed in tumor cells treated with the drugs, particularly with sorafenib. Finally, a significant mass reduction and increased survival were observed in SW13 xenograft model undergoing treatment with the drugs in combination. Our data suggest that an autocrine VEGF loop may exist within ACC. Furthermore, a combination of molecularly targeted agents may have both antiangiogenic and direct antitumor effects and thus could represent a new therapeutic tool for the treatment of ACC.

Anoikis resistance: an essential prerequisite for tumor metastasis

Metastasis is a multistep process including dissociation of cancer cells from primary sites, survival in the vascular system, and proliferation in distant target organs. As a barrier to metastasis, cells normally undergo an apoptotic process known as “anoikis,” a form of cell death due to loss of contact with the extracellular matrix or neighboring cells. Cancer cells acquire anoikis resistance to survive after detachment from the primary sites and travel through the circulatory and lymphatic systems to disseminate throughout the body. Because recent technological advances enable us to detect rare circulating tumor cells, which are anoikis resistant, currently, anoikis resistance becomes a hot topic in cancer research. Detailed molecular and functional analyses of anoikis resistant cells may provide insight into the biology of cancer metastasis and identify novel therapeutic targets for prevention of cancer dissemination. This paper comprehensively describes recent investigations of the molecular and cellular mechanisms underlying anoikis and anoikis resistance in relation to intrinsic and extrinsic death signaling, epithelial-mesenchymal transition, growth factor receptors, energy metabolism, reactive oxygen species, membrane microdomains, and lipid rafts.