177Lu-octreotate is an FDA-approved radionuclide therapy for patients with gastroenteropancreatic neuroendocrine tumours (NETs) expressing somatostatin receptors. The 177Lu-octreotate therapy has shown promising results in clinical trials by prolonging progression-free survival, but complete responses are still uncommon. The aim of this study was to improve the 177Lu-octreotate therapy by means of combination therapy. To identify radiosensitising inhibitors, two cell lines, GOT1 and P-STS, derived from small intestinal neuroendocrine tumours (SINETs), were screened with 1224 inhibitors alone or in combination with external radiation. The screening revealed that inhibitors of Hsp90 can potentiate the tumour cell-killing effect of radiation in a synergistic fashion (GOT1; false discovery rate <3.2 × 10−11). The potential for Hsp90 inhibitor ganetespib to enhance the anti-tumour effect of 177Lu-octreotate in an in vivo setting was studied in the somatostatin receptor-expressing GOT1 xenograft model. The combination led to a larger decrease in tumour volume relative to monotherapies and the tumour-reducing effect was shown to be synergistic. Using patient-derived tumour cells from eight metastatic SINETs, we could show that ganetespib enhanced the effect of 177Lu-octreotate therapy for all investigated patient tumours. Levels of Hsp90 protein expression were evaluated in 767 SINETs from 379 patients. We found that Hsp90 expression was upregulated in tumour cells relative to tumour stroma in the vast majority of SINETs. We conclude that Hsp90 inhibitors enhance the tumour-killing effect of 177Lu-octreotate therapy synergistically in SINET tumour models and suggest that this potentially promising combination should be further evaluated.
Tobias Hofving, Viktor Sandblom, Yvonne Arvidsson, Emman Shubbar, Gülay Altiparmak, John Swanpalmer, Bilal Almobarak, Anna-Karin Elf, Viktor Johanson, Erik Elias, Erik Kristiansson, Eva Forssell-Aronsson and Ola Nilsson
James Yao, Abhishek Garg, David Chen, Jaume Capdevila, Paul Engstrom, Rodney Pommier, Eric Van Cutsem, Simron Singh, Nicola Fazio, Wei He, Markus Riester, Parul Patel, Maurizio Voi, Michael Morrissey, Marianne Pavel and Matthew Helmut Kulke
Neuroendocrine tumors (NETs) have historically been subcategorized according to histologic features and the site of anatomic origin. Here, we characterize the genomic alterations in patients enrolled in three phase 3 clinical trials of NET of different anatomic origins and assess the potential correlation with clinical outcomes. Whole-exome and targeted panel sequencing was used to characterize 225 NET samples collected in the RADIANT series of clinical trials. Genomic profiling of NET was analyzed along with nongenomic biomarker data on the tumor grade and circulating chromogranin A (CgA) and neuron-specific enolase (NSE) levels from these patients enrolled in clinical trials. Our results highlight recurrent large-scale chromosomal alterations as a common theme among NET. Although the specific pattern of chromosomal alterations differed between tumor subtypes, the evidence for generalized chromosomal instability (CIN) was observed across all primary sites of NET. In pancreatic NET, although the P value was not significant, higher CIN suggests a trend toward longer survival (HR, 0.55, P = 0.077), whereas in the gastrointestinal NET, lower CIN was associated with longer survival (HR, 0.44, P = 0.0006). Our multivariate analyses demonstrated that when combined with other clinical data among patients with progressive advanced NETs, chromosomal level alteration adds important prognostic information. Large-scale CIN is a common feature of NET, and specific patterns of chromosomal gain and loss appeared to have independent prognostic value in NET subtypes. However, whether CIN in general has clinical significance in NET requires validation in larger patient cohort and warrants further mechanistic studies.
Fabia De Oliveira Andrade, Wei Yu, Xiyuan Zhang, Elissa Carney, Rong Hu, Robert Clarke, Kevin FitzGerald and Leena Hilakivi-Clarke
Resistance to endocrine therapy remains a clinical challenge in the treatment of estrogen receptor-positive (ER+) breast cancer. We investigated if adding a traditional Asian herbal mixture consisting of 12 herbs, called Jaeumkanghwa-tang (JEKHT), to tamoxifen (TAM) therapy might prevent resistance and recurrence in the ER+ breast cancer model of 7,12-dimethylbenz[a]anthracene (DMBA)-exposed Sprague–Dawley rats. Rats were divided into four groups treated as follows: 15 mg/kg TAM administered via diet as TAM citrate (TAM only); 500 mg/kg JEKHT administered via drinking water (JEKHT only group); TAM + JEKHT and no treatment control group. The study was replicated using two different batches of JEKHT. In both studies, a significantly higher proportion of ER+ mammary tumors responded to TAM if animals also were treated with JEKHT (experiment 1: 47% vs 65%, P = 0.015; experiment 2: 43% vs 77%, P < 0.001). The risk of local recurrence also was reduced (31% vs 12%, P = 0.002). JEKHT alone was mostly ineffective. In addition, JEKHT prevented the development of premalignant endometrial lesions in TAM-treated rats (20% in TAM only vs 0% in TAM + JEKHT). Co-treatment of antiestrogen-resistant LCC9 human breast cancer cells with 1.6 mg/mL JEKHT reversed their TAM resistance in dose–response studies in vitro. Several traditional herbal medicine preparations can exhibit anti-inflammatory properties and may increase anti-tumor immune activities in the tumor microenvironment. In the tumors of rats treated with both JEKHT and TAM, expression of Il-6 (P = 0.03), Foxp3/T regulatory cell (Treg) marker (P = 0.033) and Tgfβ1 that activates Tregs (P < 0.001) were significantly downregulated compared with TAM only group. These findings indicate that JEKHT may prevent TAM-induced evasion of tumor immune responses.
G Carreno, J K R Boult, J Apps, J M Gonzalez-Meljem, S Haston, R Guiho, C Stache, L S Danielson, A Koers, L M Smith, A Virasami, L Panousopoulos, M Buchfelder, T S Jacques, L Chesler, S P Robinson and J P Martinez-Barbera
Pharmacological inhibition of the sonic hedgehog (SHH) pathway can be beneficial against certain cancers but detrimental in others. Adamantinomatous craniopharyngioma (ACP) is a relevant pituitary tumour, affecting children and adults, that is associated with high morbidity and increased mortality in long-term follow-up. We have previously demonstrated overactivation of the SHH pathway in both human and mouse ACP. Here, we show that this activation is ligand dependent and induced by the expression of SHH protein in a small proportion of tumour cells. We investigate the functional relevance of SHH signalling in ACP through MRI-guided preclinical studies using an ACP mouse model. Treatment with vismodegib, a clinically approved SHH pathway inhibitor, results in a significant reduction in median survival due to premature development of highly proliferative and vascularised undifferentiated tumours. Reinforcing the mouse data, SHH pathway inhibition in human ACP leads to a significant increase in tumour cell proliferation both ex vivo, in explant cultures, and in vivo, in a patient-derived xenograft model. Together, our results demonstrate a protumourigenic effect of vismodegib-mediated SHH pathway inhibition in ACP.
Dawei Wu, Dongwei Lv, Ting Zhang, Lianying Guo, Fangli Ma, Caihua Zhang, Guofeng Lv and Lin Huang
Ewing sarcoma family tumors (ESFTs) are a group of aggressive and highly metastatic tumors lacking efficient therapies. Insulin-like growth factor 1 receptor (IGF1R) blockade is one of the most efficient targeting therapy for ESFTs. However, the appliance is obstructed by drug resistance and disease recurrence due to the activation of insulin receptor (IR) signaling induced by IGF1R blockade. Herein β-elemene, a compound derived from natural plants, exhibited a remarkable proliferation repression on ESFT cells, which was weakened by a caspase inhibitor Z-VAD. β-elemene in combination with IGF1R inhibitors enhanced markedly the repression on cellular proliferation and mTOR activation by IGF1R inhibitors and suppressed the PI3K phosphorylation induced by IGF1R inhibitors. To investigate the mechanisms, we focused on the effects of β-elemene on IR signaling pathway. β-elemene significantly suppressed the insulin-driven cell growth and the activation of mTOR and PI3K in tumor cells, while the toxicity to normal hepatocytes was much lower. Further, the phosphorylation of IR was found to be suppressed notably by β-elemene specifically in tumor cells other than normal hepatocytes. In addition, β-elemene inhibited the growth of ESFT xenografts in vivo, and the phosphorylation of IR and S6 ribosomal protein was significantly repressed in the β-elemene-treated xenografts. These data suggest that β-elemene targets IR phosphorylation to inhibit the proliferation of tumor cells specifically and enhance the effects of IGF1R inhibitors. Thus, this study provides evidence for novel approaches by β-elemene alone or in combination with IGF1R blockades in ESFTs and IR signaling hyperactivated tumors.
F Castinetti, F Albarel, F Archambeaud, J Bertherat, B Bouillet, P Buffier, C Briet, B Cariou, Ph Caron, O Chabre, Ph Chanson, C Cortet, C Do Cao, D Drui, M Haissaguerre, S Hescot, F Illouz, E Kuhn, N Lahlou, E Merlen, V Raverot, S Smati, B Verges and F Borson-Chazot
The management of cancer patients has changed due to the considerably more frequent use of immune checkpoint inhibitors (ICPIs). However, the use of ICPI has a risk of side effects, particularly endocrine toxicity. Since the indications for ICPI are constantly expanding due to their efficacy, it is important that endocrinologists and oncologists know how to look for this type of toxicity and how to treat it when it arises. In view of this, the French Endocrine Society initiated the formulation of a consensus document on ICPI-related endocrine toxicity. In this paper, we will introduce data on the general pathophysiology of endocrine toxicity, and we will then outline expert opinion focusing primarily on methods for screening, management and monitoring for endocrine side effects in patients treated by ICPI. We will then look in turn at endocrinopathies that are induced by ICPI including dysthyroidism, hypophysitis, primary adrenal insufficiency and fulminant diabetes. In each chapter, expert opinion will be given on the diagnosis, management and monitoring for each complication. These expert opinions will also discuss the methodology for categorizing these side effects in oncology using ‘common terminology criteria for adverse events’ (CTCAE) and the difficulties in applying this to endocrine side effects in the case of these anti-cancer therapies. This is shown in particular by certain recommendations that are used for other side effects (high-dose corticosteroids, contraindicated in ICPI for example) and that cannot be considered as appropriate in the management of endocrine toxicity, as it usually does not require ICPI withdrawal or high-dose glucocorticoid intake.
Sung Gwe Ahn, Chang Ik Yoon, Jae Hoon Lee, Hye Sun Lee, So Eun Park, Yoon Jin Cha, Chihwan Cha, Soong June Bae, Kyung-A Lee and Joon Jeong
On the basis of TP53 mutations and standardized uptake values (SUVs) from 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET), we sought to enhance our knowledge of the biology underlying low progesterone receptor (PR) expression in estrogen receptor (ER)-positive/human epidermal growth factor receptor-2 (HER2)-negative tumors. This study included 272 patients surgically treated for ER-positive, HER2-negative breast cancer and who had undergone TP53 gene sequencing. Of these, 229 patients also underwent 18F-FDG PET or PET/CT. Mutational analysis of exons 5–9 of the TP53 gene was conducted using PCR amplification and direct sequencing. The SUVs were measured using 18F-FDG-PET scan images. Twenty-eight (10.3%) tumors had a somatic TP53 mutation. The TP53 mutation rate was significantly higher in low-PR tumors than in high-PR tumors (17.1% vs 7.9%, P = 0.039). Low-PR tumors had significantly higher median SUVs than high-PR tumors (P = 0.046). The multivariable analysis revealed that SUV and age remained independent variables associated with low PR expression. An adverse impact of low PR expression on recurrence-free survival was observed in the multivariable Cox regression hazard model. We provide clinical evidence that genetic alteration of the TP53 gene and dysregulated glucose metabolism partly involve low PR expression in ER-positive and HER2-negative breast cancer.
Jonathan W Nyce
We recently reported our detection of an anthropoid primate-specific, ‘kill switch’ tumor suppression system that reached its greatest expression in humans, but that is fully functional only during the first twenty-five years of life, corresponding to the primitive human lifespan that has characterized the majority of our species' existence. This tumor suppression system is based upon the kill switch being triggered in cells in which p53 has been inactivated; such kill switch consisting of a rapid, catastrophic increase in ROS caused by the induction of irreversible uncompetitive inhibition of glucose-6- phosphate dehydrogenase (G6PD), which requires high concentrations of both inhibitor (DHEA) and G6P substrate. While high concentrations of intracellular DHEA are readily available in primates from the importation and subsequent de-sulfation of circulating DHEAS into p53-affected cells, both an anthropoid primate-specific sequence motif (GAAT) in the glucose-6-phosphatase (G6PC) promoter, and primate-specific inactivation of de novo synthesis of vitamin C by deletion of gulonolactone oxidase (GLO) were required to enable accumulation of G6P to levels sufficient to enable irreversible uncompetitive inhibition of G6PD. Malignant transformation acts as a counterforce opposing vertebrate speciation, particularly increases in body size and lifespan that enable optimized exploitation of particular niches. Unique mechanisms of tumor suppression that evolved to enable niche exploitation distinguish vertebrate species, and prevent one vertebrate species from serving as a valid model system for another. This here-to-fore unrecognized element of speciation undermines decades of cancer research data, using murine species, which presumed universal mechanisms of tumor suppression, independent of species. Despite this setback, the potential for pharmacological reconstitution of the kill switch tumor suppression system that distinguishes our species suggests that ‘normalization’ of human cancer risk, from its current 40% to the 4% of virtually all other large, long-lived species, represents a realistic near-term goal.
Xianhui Ruan, Xianle Shi, Qiman Dong, Yang Yu, Xiukun Hou, Xinhao Song, Xi Wei, Lingyi Chen and Ming Gao
There is no effective treatment for patients with poorly differentiated papillary thyroid cancer or anaplastic thyroid cancer (ATC). Anlotinib, a multi-kinase inhibitor, has already shown antitumor effects in various types of carcinoma in a phase I clinical trial. In this study, we aimed to better understand the effect and efficacy of anlotinib against thyroid carcinoma cells in vitro and in vivo. We found that anlotinib inhibits the cell viability of papillary thyroid cancer and ATC cell lines, likely due to abnormal spindle assembly, G2/M arrest, and activation of TP53 upon anlotinib treatment. Moreover, anlotinib suppresses the migration of thyroid cancer cells in vitro and the growth of xenograft thyroid tumors in mice. Our data demonstrate that anlotinib has significant anticancer activity in thyroid cancer, and potentially offers an effective therapeutic strategy for patients of advanced thyroid cancer type.
Simon Linder, Henk G van der Poel, Andries M Bergman, Wilbert Zwart and Stefan Prekovic
The androgen receptor drives the growth of metastatic castration-resistant prostate cancer. This has led to the development of multiple novel drugs targeting this hormone-regulated transcription factor, such as enzalutamide – a potent androgen receptor antagonist. Despite the plethora of possible treatment options, the absolute survival benefit of each treatment separately is limited to a few months. Therefore, current research efforts are directed to determine the optimal sequence of therapies, discover novel drugs effective in metastatic castration-resistant prostate cancer and define patient subpopulations that ultimately benefit from these treatments. Molecular studies provide evidence on which pathways mediate treatment resistance and may lead to improved treatment for metastatic castration-resistant prostate cancer. This review provides, firstly a concise overview of the clinical development, use and effectiveness of enzalutamide in the treatment of advanced prostate cancer, secondly it describes translational research addressing enzalutamide response vs resistance and lastly highlights novel potential treatment strategies in the enzalutamide-resistant setting.