In silico approach of modified melanoma peptides and their immunotherapeutic potential.

Melanoma is a type of skin cancer with increasing incidence worldwide and high lethality. Conventional forms of treatment are not effective in advanced cancer stages. Hence, immunotherapeutic approaches have been tested to modulate immune response against tumor cells. Some vaccine models using tumor-associated antigens (TAAs) such as glycoprotein 100 (gp100) have been studied, but their expected effectiveness has not been shown until now. Antigen immunogenicity is a crucial point to improve the immune response, and therefore mutations are inserted in peptide sequences. It is possible to understand the interactions which occur between peptides and immune system molecules through computer simulation, and this is essential in order to guide efficient vaccine models. In this work, we have calculated the interaction binding energies of crystallographic data based on modified gp100 peptides and HLA-A*0201 using density functional theory (DFT) and the molecular fractionation with conjugated caps (MFCC) approach. Our results show the most relevant residue-residue interactions, the impact of three mutations in their binding sites, and the main HLA-A*0201 amino acids for peptide-HLA binding.

Negative correlation between tumour size and cortisol/ACTH ratios in patients with Cushing's disease harbouring microadenomas or macroadenomas.

PURPOSE: Pituitary macroadenomas (MACs) represent 10-30 % of Cushing's disease (CD) cases. The aim of this study was to report the clinical, laboratorial and imaging features and postsurgical outcomes of microadenoma (MIC) and MAC patients. METHODS: Retrospective study with 317 CD patients (median 32 years old, range 9-71 years) admitted between 1990 and 2014, 74 (23.3 %) of whom had MAC. RESULTS: Hirsutism, plethora facial, muscular weakness and muscular atrophy were more frequent in the MIC patients. Nephrolithiasis, osteopenia, hyperprolactinaemia and galactorrhoea were more prevalent in MAC patients. The morning serum cortisol (Fs), nocturnal salivary cortisol (NSC), nocturnal Fs (Fs 2400 h), low- and high-dose dexamethasone suppression test results and CRH and desmopressin test results were similar between the subgroups. MIC patients showed higher urinary cortisol at 24 h (UC), and MAC patients presented higher ACTH levels but lower Fs/ACTH, Fs 2400 h/ACTH, NSC/ACTH and UC/ACTH ratios. There were negative correlations of tumour size with Fs/ACTH, Fs 2400 h/ACTH, NSC/ACTH and UC/ACTH ratios. Overall, the postsurgical remission and recurrence rates were similar between MIC and MAC. However, patients in remission (MIC + MAC) showed smaller tumour diameters and a lower prevalence of invasion and extension on MRI. CONCLUSIONS: Despite exhibiting higher plasma ACTH levels, CD patients with MAC presented lower cortisol/ACTH ratios than did patients with MIC, with a negative correlation between tumour size and cortisol/ACTH ratios. The overall postsurgical remission and recurrence rates were similar between MIC and MAC patients, with those with larger and/or invasive tumours showing a lower remission rate.