Potential novel targets for Alzheimer pharmacotherapy: II. Update on secretase inhibitors and related approaches.

WHAT IS KNOWN AND OBJECTIVE: The prevailing theory regarding Alzheimer disease (AD) is that insoluble amyloid ß-peptide (Aß) plays a critical role in the cortical plaques characteristic of the disease. Because Aß is formed from the sequential splicing of amyloid precursor protein (APP) catalysed by 'secretase' enzymes (α, ß and γ), clinical trials of secretase inhibitors will either result in beneficial pharmacotherapy or, if negative, cast doubt on the role of Aß in AD. With recent clinical trial failures, is the Aß theory wrong? METHODS: Literature searches were conducted on the topics of secretases and clinical trials, including PubMed searches, United States clinical trials directory, pharmaceutical company websites and news reports. The information was collected and evaluated for relevance and quality. RESULTS AND DISCUSSION: Several direct-acting (e.g. CTS-21166, LY2811376) and indirect-acting (e.g. ACI-91) ß-secretase inhibitors and several γ-secretase inhibitors (e.g. avagacestat, JNJ-40418677 and semagacestat) have not fared well in early clinical trials due to the lack of efficacy or concerns over possible serious side effects. WHAT IS NEW AND CONCLUSION: The failures of secretase inhibitors in clinical trials appear to bring into question the long-hypothesized association between AD and Aß production. However, the disease might have been too advanced in these patients to benefit from this type of therapy (mainly preventive). Secretase inhibitors are still being studied, along with new diagnostic tools, with the hope of testing patients earlier, that is, with less advanced disease. If these trials also fail, the prevailing view of the role of Aß in AD will truly be in doubt.

Total neoadjuvant therapy for rectal cancer: Making sense of the results from the RAPIDO and PRODIGE 23 trials.

A few months ago, results from two randomised phase III trials of total neoadjuvant therapy (TNT) in locally advanced rectal cancer were presented (RAPIDO and PRODIGE 23), consistently showing better short- and long-term outcomes with TNT as compared with standard neoadjuvant long-course chemoradiotherapy (CRT) or short-course radiotherapy (SCRT). These results represent corroborating evidence in support of a practice that many centres had already implemented based on promising preliminary data. Also, they provide new, high-level evidence to endorse TNT as a new management option in the treatment algorithm of stage II-III rectal cancer in those centres where CRT and SCRT have long remained the only accepted standard neoadjuvant treatments. Having two consistently positive trials is certainly reassuring regarding the potential of TNT as a general treatment approach. Nevertheless, substantial differences between these trials pose important challenges in relation to the generalisability and applicability of their results, and translation of the same into practical clinical recommendations. In this article, we address a number of key questions that the RAPIDO and PRODIGE 23 trials have raised among the broad community of gastrointestinal oncologists, proposing an interpretation of the data that may help the decision making, and highlighting grey areas that warrant further investigation.

Triple blockade of EGFR, MEK and PD-L1 has antitumor activity in colorectal cancer models with constitutive activation of MAPK signaling and PD-L1 overexpression.

BACKGROUND: Molecular mechanisms driving acquired resistance to anti-EGFR therapies in metastatic colorectal cancer (mCRC) are complex but generally involve the activation of the downstream RAS-RAF-MEK-MAPK pathway. Nevertheless, even if inhibition of EGFR and MEK could be a strategy for overcoming anti-EGFR resistance, its use is limited by the development of MEK inhibitor (MEKi) resistance. METHODS: We have generated in vitro and in vivo different CRC models in order to underline the mechanisms of MEKi resistance. RESULTS: The three different in vitro MEKi resistant models, two generated by human CRC cells quadruple wild type for KRAS, NRAS, BRAF, PI3KCA genes (SW48-MR and LIM1215-MR) and one by human CRC cells harboring KRAS mutation (HCT116-MR) showed features related to the gene signature of colorectal cancer CMS4 with up-regulation of immune pathway as confirmed by microarray and western blot analysis. In particular, the MEKi phenotype was associated with the loss of epithelial features and acquisition of mesenchymal markers and morphology. The change in morphology was accompanied by up-regulation of PD-L1 expression and activation of EGFR and its downstream pathway, independently to RAS mutation status. To extend these in vitro findings, we have obtained mouse colon cancer MC38- and CT26-MEKi resistant syngeneic models (MC38-MR and CT26-MR). Combined treatment with MEKi, EGFR inhibitor (EGFRi) and PD-L1 inhibitor (PD-L1i) resulted in a marked inhibition of tumor growth in both models. CONCLUSIONS: These results suggest a strategy to potentially improve the efficacy of MEK inhibition by co-treatment with EGFR and PD-L1 inhibitors via modulation of host immune responses.

Seroepidemiologic study of HCV genotypes in the district of Messina and Catania.

Aim of the study was to identify the different hepatitis C virus (HCV) genotypes in chronic hepatitis patients living in the districts of Messina and Catania (Sicily, Italy), for epidemiological reasons but also to determine the effect of interferon therapy on therapeutic response of different viral genotypes. Genotyping was carried out by reverse-hybridization after amplification by polymerase chain reaction. The study was conducted on 271 patients with HCV-RNA positive chronic liver disease belonging to categories at risk or not for infection. HCV genotype sub-type 1b was the most common viral genotype identified.

Hepatitis C virus genotypes in elderly patients with chronic hepatitis C.

The importance of determination of hepatitis C virus (HCV) genotypes and subtypes has been demonstrated not only as epidemiological characteristics, but also as prognostic factors regarding the seriousness of the disease and response to interferon (IFN) in patients with chronic hepatitis C (CHC). Aim of this study was to determine HCV genotypes in a group of elderly patients with CHC, in order to acquire epidemiological data on the prevalence of HCV genotypes in Eastern Sicily, and to evaluate any relationship with the seriousness of the disease and with the response to IFN. The study was carried out on 22 patients with CHC, aged from 65 to 75 years. The prevalence of HCV-RNA subtypes in elderly patients (Group A) was compared with two other groups: Group B aged from 36 to 64 years; and Group C aged from 20 to 35 years. HCV-RNA proved to be positive in 20 of the 22 patients in Group A, and in 100% of these cases the prevalent subtype was 1b; in the other two groups the occurrence of other subtypes was more frequent, especially in the younger ages. In conclusion, the subtype 1b is indigenous in our region and it cannot be proposed as the only prognostic factor for seriousness of the disease and response to IFN, especially in elderly patients.

Chronic hepatitis C in elderly patients: clinical, histological and virological features.

Some clinical, histological and virological features, efficacy and safety of interferon (IFN) therapy were evaluated in elderly patients with chronic hepatitis C (CHC). We enrolled 22 patients aged 65-75 (mean age: 68.3 +/- 3.17 years); 15 males and 7 females. In all cases the hepatitis C virus RNA (HCV-RNA) was determined before, during and after the therapy, and HCV sub-types were established; 15 patients underwent hepatobiopsy. At entry, the duration of disease was: 6 patients 1-3 years, 2 patients 4-10 years, 14 patients 11-30 years; alanine-aminotransferase (ALT) = (3.17 +/- 1.15) x N (N = normal value); aspartate-transaminase (AST) = 2.28 +/- 1.6 x N; gamma-glutamyl-transpeptidase (gGT) = 1.4 +/- 1.1 x N; platelets = 164,000 +/- 66,000/mm(3); histological pattern: 2 mild chronic active hepatitis (CAH), 5 CAH, 2 severe CAM, 6 CAH with liver cirrhosis (LC); histological activity index (HAI) (14 patients) = 11.14 +/- 4.5 (range 5-17); scores according to Scheuer: lobular 2.28 +/- 1.13, portal 2.71 +/- 0.99, fibrosis 2.35 +/-1.33; HCV-RNA +ve: 20 patients, HCV-RNA -ve: 2 patients; HCV-subtypes: 1b 20/20 (100%), 1b+1a 1/20 (5%), 1b+ 2a 1/20 (5%). Treatment was applied to 18 patients, for 3-12 months; 5 received alpha-IFN2a; 5 received alpha-IFN2b, 3 lymphoblastoid IFN, all at a dose of 3 mU thrice per week; 3 patients received 6 mU beta-IFN thrice per week. Therapy over 6 months was applied to 16 patients: Complete response (CR) was observed in 8 patients (50%), one of them was with long-term CR (over 12 months after therapy); 5 have had relapse and 2 patients are still under treatment. Partial response (PR) was observed in 4 patients (25%), no response (NR) in 4 patients (25%). Side effects were moderate and self-limited. Loss of HCV-RNA was shown in some patients with PR and in all patients with CR, but only temporarily.

[Single maxillary central incisor and holoprosencephaly]. / Incisivo mascellare centrale unico e oloprosencefalia.

A holoprosencephalic female was born to a mother with a single central maxillary incisor. The newborn had microcephaly, hypotelorism, cebocephaly, palatoschisis, micrognathia, and normal chromosomes. Her brain computed tomography showed alobar holoprosencephaly. The mother was of normal intelligence and stature, and her brain computed tomography was normal. Other relatives did not have single central maxillary incisors, hypotelorism, or oral clefts. We show a further evidence of a single central maxillary incisor as an indicator of potential holoprosencephaly in the next generation, confirming an autosomal dominant trait with wide variety in penetrance and expressivity.

[10 years' surveillance of congenital malformations in Liguria (1978-1987)]. / Dieci anni di sorveglianza sulle malformazioni congenite in Liguria (1978-1987).

In 10 years 26,945 newborns were born in 4 different hospitals in Liguria. The incidence rates of 26 specific malformations are reported. The regional data are related to those of the Italian Multicentric Monitoring System for Birth Defects.