Luisa Circelli

Lessons to be learned from the clinical management of a MEN 2A patient bearing a novel 634/640/700 mutation of the RET proto‐oncogene

A cluster of germline gain-of-function mutations of the RET proto-oncogene are responsible for Multiple Endocrine Neoplasia type 2A (MEN 2A), an autosomal dominant, inherited disorder characterized by medullary thyroid carcinoma (MTC), phaeochromocytoma (Phaeo) and hyperparathyroidism. Genetic screening of MEN 2A patients has been available for the past decade and useful genotype–phenotype correlations have been established: specific RET mutations are associated with age at first diagnosis and tumour aggressiveness. Accordingly, MEN 2A patients can be stratified into three risk groups depending on the RET mutation. Management uncertainties remain regarding patients bearing uncommon RET mutations or genetic variations for which mutation-specific risk profiles and treatment recommendations are unavailable. Here we report the thirteen-year clinical and surgical follow-up of a patient with MEN 2A bearing three de novo RET mutations at codons 634, 640 and 700 (p. C634R, p.A640G and p.M700L) in exon 11: a combination of mutations which has not previously been described. In May 1998, a 26-year-old female patient was admitted to our unit because of recurrent episodes of hypertension, tachycardia and headache. She had recently been diagnosed with a MTC which had been removed surgically, with associated cervical central lymphectomy. Elevated urinary catecholamine levels and imaging examinations showing a left adrenal mass were suggestive of a Phaeo. Hyperplasia of the contralateral gland was also detected. The patient underwent left “open” adrenalectomy 3 months later; post-operative catecholamine levels decreased to normal values, while the serum calcitonin remained elevated (Fig. 1). The diagnosis of MEN 2A was confirmed by testing the patient’s DNA for RET mutations. Two heterozygous germline mutations were identified: a transition at position c.1900 replaced a T with a C and a transversion at position c.1919 replaced a C with a G, resulting in the substitution of a cysteine with an arginine and an alanine with a glycine at positions p.634 and p.640, respectively. The patient presented with MTC and Phaeo without parathyroid gland involvement, so we speculated that this clinical picture could be correlated with the two RET mutations identified and the unusual feature of calcitonin production by the adrenal tissue. No clinical symptoms suggestive of MEN 2A and no RET mutations were found in either parent or any of the available relatives tested (three sisters and one brother). In 2003, at

CDKN1B V109G polymorphism a new prognostic factor in sporadic medullary thyroid carcinoma

CONTEXT CDKN1B encodes the cyclin-dependent kinase inhibitor p27Kip1 and is mutated in multiple endocrine neoplasia-like syndromes. CDKN1B also harbors single nucleotide polymorphisms; the T/G transversion at nucleotide 326 (the V109G variant) has been reported to be protective in breast, hereditary prostate, and pancreatic tumors. Association of CDNK1B mutations or polymorphisms with sporadic medullary thyroid carcinoma (MTC) has not been investigated yet. OBJECTIVE AND DESIGN We screened germline DNA from 84 patients affected by sporadic MTC and 90 healthy age- and gender-matched controls for CDKN1B mutations or polymorphisms by PCR amplification and sequencing of the amplicons. We also tested all germline and 50 tumor tissue DNA for RET proto-oncogene mutations. Computed tomography, ultrasound scans, and serum calcitonin were carried out before surgery and during the follow-up and associated with CDKN1B polymorphism and disease remission. RESULTS The T/G transversion at nucleotide 326 was the only DNA variation detected. The overall frequency of the T/G and G/G alleles in combination was 46.4%. This variant (V109G) was correlated with post-operative calcitonin levels in the normal range and biochemical remission. Conversely, the wild-type (T/T) allele was associated with post-operative calcitonin levels above normal and a higher risk to develop clinical recurrence and distant metastases. Somatic RET mutations were significantly associated with a more aggressive behavior especially in wild-type allele-bearing patients. CONCLUSIONS Collectively, in sporadic MTC, the CDKN1B V109G polymorphism correlates with a more favorable disease progression than the wild-type allele and might be considered a new promising prognostic marker.

Impact of long-acting octreotide in patients with early-stage MEN1-related duodeno-pancreatic neuroendocrine tumours

Somatostatin analogues (SSA) represent one of the main therapeutic option in patients affected with functioning well‐differentiated neuroendocrine tumours (NETs). There are no studies specifically focusing on NETs associated with Multiple Endocrine Neoplasia type 1 (MEN1).

Animal models of medullary thyroid cancer: state of the art and view to the future

Medullary thyroid carcinoma is a neuroendocrine tumour originating from parafollicular C cells accounting for 5-10% of thyroid cancers. Increased understanding of disease-specific molecular targets of therapy has led to the regulatory approval of two drugs (vandetanib and cabozantinib) for the treatment of medullary thyroid carcinoma. These drugs increase progression-free survival; however, they are often poorly tolerated and most treatment responses are transient. Animal models are indispensable tools for investigating the pathogenesis, mechanisms for tumour invasion and metastasis and new therapeutic approaches for cancer. Unfortunately, only few models are available for medullary thyroid carcinoma. This review provides an overview of the state of the art of animal models in medullary thyroid carcinoma and highlights future developments in this field, with the aim of addressing salient features and clinical relevance.

Prognostic role of the CDNK1B V109G polymorphism in multiple endocrine neoplasia type 1.

CDKN1B encodes the cyclin‐dependent kinase inhibitor p27/Kip1. CDKN1B mutations and polymorphisms are involved in tumorigenesis; specifically, the V109G single nucleotide polymorphism has been linked to different tumours with controversial results. Multiple endocrine neoplasia type 1 (MEN1) is a rare autosomal dominant syndrome, characterized by the development of different types of neuroendocrine tumours and increased incidence of other malignancies. A clear genotype–phenotype correlation in MEN1 has not been established yet. In this study, we assessed whether the CDKN1B V109G polymorphism was associated with the development of aggressive tumours in 55 consecutive patients affected by MEN1. The polymorphism was investigated by PCR amplification of germline DNA followed by direct sequencing. Baseline and follow‐up data of tumour types and their severity were collected and associated with the genetic data. MEN1‐related aggressive and other malignant tumours of any origin were detected in 16.1% of wild‐type and 33.3% of polymorphism allele‐bearing patients (P = NS). The time interval between birth and the first aggressive tumour was significantly shorter in patients with the CDKN1B V109G polymorphism (median 46 years) than in those without (median not reached; P = 0.03). Similarly, shorter was the time interval between MEN1 diagnosis and age of the first aggressive tumour (P = 0.02). Overall survival could not be estimated as 96% patients were still alive at the time of the study. In conclusion, CDKN1B V109G polymorphism seems to play a role in the development of aggressive tumours in MEN1.

Immunological effects of a novel RNA-based adjuvant in liver cancer patients

Evaluation of biological effects of adjuvants on immune cells has been assessed in a limited number of studies. Moreover, no data are available on samples derived from cancer patients who may have a severe immune impairment. The effects of a novel RNA-based adjuvant (RNAdjuvant® developed by CureVac) were assessed in an ex vivo setting on PBMCs obtained from 8 healthy volunteers and 17 HCC patients, using a multiparametric approach to analyze network dynamics of early immune responses. Evaluation of CD80, CD86 and HLA-DR expression, cytokine production as well as gene expression was performed. Moreover, the downstream effect on CD4+ T cell phenotyping was evaluated. Treatment with RNAdjuvant® showed comparable effects on PBMCs of both HCC and healthy subjects. In particular, CD80, CD86 and HLA-DR expression was found up-regulated in circulating dendritic cells, which promoted a CD4+ T cell differentiation toward an effector phenotype. A mixed Th1/Th2 cytokine pattern was induced, although a more predominant production of TNFα and IFNγ was observed in HCC patients versus healthy controls. The cytokine profile was further confirmed by gene transcriptional analysis, which showed up-regulation of several genes involved in innate and adaptive immune-related pathways. The present study is the first demonstration that HCC patients and healthy subjects are equally responsive to an adjuvant. This may suggest that the same vaccine formulation including the RNAdjuvant® might have similar potency in healthy subjects and cancer patients.

CXCR4/CXCL12/CXCR7 axis is functional in neuroendocrine tumors and signals on mTOR

Objective To evaluate the possible crosstalk between C-X-C chemokine receptor 4 (CXCR4)/C-X-C motif chemokine 12 (CXCL12)/C-X-C chemokine receptor 7 (CXCR7) axis with the mammalian target of rapamycin (mTOR) pathway in neuroendocrine tumors (NETs). Methods Sixty-one human NETs were included into the study. CXCR4/CXCL12/CXCR7 axis and mTOR pathway were assessed by qRT-PCR and immunohistochemistry (IHC). The effect of mTOR inhibitor, RAD001, was evaluated on CXCR4 pathway through proliferation and p-Erk and p-AKT induction. Results: CXCR4/CXCL12/CXCR7 axis and p-mTOR were found to be active and correlated with grading, Ki67 index and tumor stage. mTOR pathway activation significantly correlated with poor prognosis. In human NET cells, CXCL12 induced mTOR signalling while AMD3100 (CXCR4-antagonist) impaired it. The mTOR-antagonist, RAD001, impaired the CXCL12-dependent induction of CXCR4 downstream effectors. Combination of AMD3100 and RAD001 potentiate cell growth inhibition. Conclusions CXCR4/CXCL12/CXCR7 axis is active in NETs and signals on mTOR. CXCR4 might be considered a prognostic factor in NETs. Combined treatment with AMD3100 and RAD001 may provide clinical benefits in NET patients with drug-resistant.

Epigenome-wide association study in hepatocellular carcinoma: Identification of stochastic epigenetic mutations through an innovative statistical approach

Hepatocellular carcinoma (HCC) results from accumulation of both genetic and epigenetic alterations. We investigated the genome-wide DNA methylation profile in 69 pairs of HCC and adjacent non-cancerous liver tissues using the Infinium HumanMethylation 450K BeadChip array. An innovative analytical approach has been adopted to identify Stochastic Epigenetic Mutations (SEMs) in HCC. HCC and peritumoral tissues showed a different epigenetic profile, mainly characterized by loss of DNA methylation in HCC. Total number of SEMs was significantly higher in HCC tumor (median: 77,370) than in peritumoral (median: 5,656) tissues and correlated with tumor grade. A significant positive association emerged between SEMs measured in peritumoral tissue and hepatitis B and/or C virus infection status. A restricted number of SEMs resulted to be shared by more than 90% of HCC tumor samples and never present in peritumoral tissue. This analysis allowed the identification of four epigenetically regulated candidate genes (AJAP1, ADARB2, PTPRN2, SDK1), potentially involved in the pathogenesis of HCC. In conclusion, HCC showed a methylation profile completely deregulated and very far from adjacent non-cancerous liver tissues. The SEM analysis provided valuable clues for further investigations in understanding the process of tumorigenesis in HCC.

Second-line sunitinib as a feasible approach for iodine-refractory differentiated thyroid cancer after the failure of first-line sorafenib

About 5 % of patients with differentiated thyroid cancer (DTC) show RAI-refractory disease, thus having a poor prognosis [1, 2]. Tyrosine-kinase inhibitors (TKIs) has represented a revolution in the management of iodinerefractory DTC [3]. Sorafenib has been the most studied TKI in this field, showing encouraging results in several retrospective and phase II studies [4–8]. Effectiveness of sorafenib in RAI-refractory DTC has been definitely demonstrated in the phase III trial DECISION, where a significant improvement of median progression-free survival (PFS) in the treatment group, as compared with placebo, was reported (10.8 vs 5.8 months; HR 0.58, 95 % CI 0.45–0.75, p\ 0.0001) [9]. Following this finding, sorafenib has became the first TKI approved by the US Food and Drug Administration (FDA) for the treatment of RAIrefractory DTC. Given that the study cohort of the DECISION trial included only TKIs-naive patients, sorafenib can be fully considered the first-line systemic therapy for this clinical setting. Nevertheless, sorafenib has some crucial limits. As reported for all TKIs, it is never curative and has a temporally limited effect. Furthermore, sorafenib induced the development of adverse events leading to drug withdrawal in about 20 % of patients [9]. To date, clear indications about management of RAI-refractory DTC patients after the failure of first-line sorafenib are lacking. Sunitinib is a TKI with a pharmacodynamic profile similar to sorafenib, but broader, targeting RET, c-Kit, VEGFR1, -2, PDGFR-a and -b [10]. Despite few studies have been performed so far, sunitinib seems to be effective for the treatment of RAI-refractory DTC [11–14]. Furthermore, several trials of renal cancer have showed that sunitinib was effective in achieving clinical benefit in the majority of patients who experienced the failure of first-line sorafenib [15], even inducing a longer median PFS. Hence, sunitinib may represent a feasible option as salvage treatment after sorafenib failure also in iodine-refractory DTC. Here we report clinical histories of 3 patients (followed at Federico II University, Department of Clinical Medicine and Surgery, Section of Endocrinology, Naples) with iodinerefractory DTC who were treated with sunitinib after the failure of first-line sorafenib.

Systems Biology Approach for Cancer Vaccine Development and Evaluation

Therapeutic cancer vaccines do not hold promise yet as an effective anti-cancer treatment. Lack of efficacy or poor clinical outcomes are due to several antigenic and immunological aspects that need to be addressed in order to reverse such trends and significantly improve cancer vaccines’ efficacy. The newly developed high throughput technologies and computational tools are instrumental to this aim allowing the identification of more specific antigens and the comprehensive analysis of the innate and adaptive immunities. Here, we review the potentiality of systems biology in providing novel insights in the mechanisms of the action of vaccines to improve their design and effectiveness.