Preclinical Models to study the Biology and Therapy of Ovarian Cancer

Ovarian cancer (OC) is one of the most common gynaecological malignancies and a cause of mortality among western women. Standard-of-care treatment consists of platinum/taxane-based chemotherapy, but 5-years survival rate remains low. Germline and somatic mutations in BRCA are present in half of the high grade serous (HGS) ovarian cancer. Olaparib, a PARP inhibitor affecting DNA damage repair pathway, has been approved in the treatment of germline-BRCA-mutated patients. The combination with cediranib, an angiogenesis inhibitor, has shown promising results, increasing progression-free survival in women with recurrent HGS ovarian cancer. In this thesis, patient-derived ovarian cancer xenografts (OC-PDX) were used to study olaparib therapy and mechanisms underlying the observed benefit of the combination. Next Generation Sequencing and gene expression analysis were performed on OC-PDX to identify mutations/aberrations in BRCA1/2 and other genes connected to the DNA repair pathway. A cohort (n=13) of OC-PDX was selected and classified as BRCAness and Not BRCAness, accordingly to their proficiency or deficiency in DNA damage repair. Olaparib and cediranib were administered in short-term (4 weeks) or maintenance (until progression) regimens. Olaparib showed activity in BRCAness OC-PDX; the effect was improved by cediranib, inducing durable responses even after treatment suspension. Of note, the combination was also beneficial in Not BRCAness OC-PDX, promoting stable disease and regression. The effect of the combination on changes in tumor-associated vasculature and hypoxia (likely due to cediranib) and DNA damage repair (due to olaparib), together with preliminary data on gene expression and mutational status, suggested a potential “cumulative” effect of the combination after 4 weeks of treatment. Studies are ongoing, to understand the molecular determinants that accompany the response of OC-PDX to the combination. The results obtained compel us to believe that the combination of olaparib with cediranib is advantageous both in DNA repair proficient and, most importantly, in deficient patients, and has to be administered until tumor progression

Platinum sensitivity and DNA repair in a recently established panel of patient-derived ovarian carcinoma xenografts

A xenobank of patient-derived (PDX) ovarian tumor samples has been established consisting of tumors with different sensitivity to cisplatin (DDP), from very responsive to resistant. As the DNA repair pathway is an important driver in tumor response to DDP, we analyzed the mRNA expression of 20 genes involved in the nucleotide excision repair, fanconi anemia, homologous recombination, base excision repair, mismatch repair and translesion repair pathways and the methylation patterns of some of these genes. We also investigated the correlation with the response to platinum-based therapy. The mRNA levels of the selected genes were evaluated by Real Time-PCR (RT-PCR) with ad hoc validated primers and gene promoter methylation by pyrosequencing. All the DNA repair genes were variably expressed in all 42 PDX samples analyzed, with no particular histotype-specific pattern of expression. In high-grade serous/endometrioid PDXs, the CDK12 mRNA expression levels positively correlated with the expression of TP53BP1, PALB2, XPF and POLB. High-grade serous/endometrioid PDXs with TP53 mutations had significantly higher levels of POLQ, FANCD2, RAD51 and POLB than high-grade TP53 wild type PDXs. The mRNA levels of CDK12, PALB2 and XPF inversely associated with the in vivo DDP antitumor activity; higher CDK12 mRNA levels were associated with a higher recurrence rate in ovarian patients with low residual tumor. These data support the important role of CDK12 in the response to a platinum based therapy in ovarian patients

Combination therapy in cancer: effects of angiogenesis inhibitors on drug pharmacokinetics and pharmacodynamics

Abstract Validated preclinical studies have provided evidence that anti-vascular endothelial growth factor (VEGF) compounds enhance the activity of subsequent antitumor therapy, but the mechanism of this potentiation is far from clear. The most widespread explanation is enhanced delivery of therapeutics due to vascular remodeling, lower interstitial pressure, and increased blood flow. While the antiangiogenic effects on vascular morphology have been fairly consistent in both preclinical and clinical settings, the improvement of tumor vessel function is debated. This review focuses on the effect of anti-VEGF therapy on tumor microenvironment morphology and functions, and its therapeutic benefits when combined with other therapies. The uptake and spatial distribution of chemotherapeutic agents into the tumor after anti-VEGF are examined

Testing for fecal gluten immunogenic peptides: a useful tool to evaluate compliance with gluten-free diet by celiacs

Background: Although experts agree that strict dietary compliance is fundamental for the health of celiac patients, there are no evidence-based recommendations on the best way to assess dietary compliance. Detection of gluten immunogenic peptides (GIPs) in feces was recently proposed as an effective method of assessing the dietary compliance of celiac patients. Methods: Fifty-five consecutive celiac patients (27 adults and 28 children, age 6-72 years), who had been on a gluten-free diet for at least 2 years, were enrolled. All patients were evaluated clinically for symptoms, physical parameters and laboratory parameters. Dietary compliance was assessed with the Biagi questionnaire and serum anti-tissue transglutaminase (tTG) IgA antibodies were measured. GIPs were determined by immunoenzymatic assay on an automated Chorus analyzer (DIESSE Diagnostica Senese), after extraction of fecal samples by the method developed by DIESSE. Results: Eight patients tested positive for GIPs (GIPs+); 71.4% of GIP-positive patients were asymptomatic; tTG antibodies were detected in 3/8 GIP+ patients. The Biagi score was significantly associated with fecal positivity for GIPs (P=0.02). However, according to the Biagi score, 57.1% of GIP+ patients followed the diet strictly and 5.4% of GIP- subjects did not comply with the diet or made substantial mistakes. Conclusions: Assay of fecal GIPs identified more patients who did not comply with the diet than did the Biagi questionnaire, evaluation of symptoms or anti-tTG antibodies. Detection of fecal GIPs offers a direct, objective, quantitative assessment of even occasional exposure to gluten and is confirmed as a practical way to check dietary compliance. © 2020, Hellenic Society of Gastroenterology. All rights reserved

Disturbi dell’umore e patologie glutine correlate. Mood disorders and gluten-related diseases

Background. Immune activation against gluten has been studied and well described in several mental disorders, including Schizophrenia, but systematic and conclusive data pertaining to mood disorders (MD) is still lacking. The study aims to assess whether MD are related to an immune response against gluten. Methods. Patients were administered the following psychometric tools: (a) Mini International Neuropsychiatric Interview (MINI), i.e. a semi-structured clinical interview, to confirm the diagnosis; (b) Hamilton Rating Scale for Depression (HAM-D) and Hamilton Rating Scale for Anxiety (HAM-A) to evaluate depressive and anxiety symptomatology, respectively; (c) Positive and Negative Symptoms Scale (PANSS) e Young Mania Rating Scale to evaluate psychotic and manic symptoms. Controls received the Structured Clinical Interview for DSM-IV-Non Patients Version (SCID-NP) to rule out the presence of current or past psychiatric disorders. Statistical analyses were performed with non-parametric tests. Serum samples from the 60 patients diagnosed with MD and from the 48 healthy controls, genetically unrelated with the 60 patients, were analyzed for IgA and IgG anti-transglutaminase antibodies (tTG), IgA antiendomysial antibodies (EMA), IgA and IgG anti-gliadin antibodies (AGA) and IgA and IgG anti-deamidated gliadin peptides antibodies (DGP). All antibody tests were run with enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence technique (IFI) (Eurospital, Trieste, Italy). Results. Only the tTG IgG levels resulted significantly higher in patients than controls (p < 0.007), whose mean values were 16.3 ± 11.8 in the patient group and 11.2±10.0 in the control group. When evaluating subgroups of recruited subject-patients with/without comorbidity of autoimmune or inflammatory diseases, controls with/without comorbidity of autoimmune or inflammatory diseases-tTG IgG results were similar in patients with or without comorbidity. On the contrary, a significant difference (p <0.004) in the subgroups without comorbidity was observed between tTG IgG of patients (16.6 ± 11.7) and tTG IgG of controls (10.2± 8.8). Conclusions. Subjects with MD do not seem to be at higher risk of suffering celiac disease (CD) or non-celiac gluten sensitivity than general population. tTG IgG autoantibodies seem to be typical of MD, in whom may not be related to a specific/primary autoimmune or inflammatory disease. Yet, they might represent an aetiopathogenetic factor for the development of psychatric disorder or a secondary effect of the psychiatric disorder on the immunary syste

A study on the association of mood disorders and gluten-related diseases

Our study aimed to evaluate the presence of antibodies related to gluten intolerance in patients with mood disorders. A total of 60 patients with a diagnosis of bipolar disorder or depressive disorder were recruited. Fourty-eight subjects randomly selected among unrelated family members were included as controls. Celiac disease-associated antibodies were assayed both in the patients and controls. Mean values of IgA/IgG anti-gliadin antibodies, IgA/IgG anti-deamidated gliadin peptide antibodies and IgA anti-transglutaminase (tTG) antibodies were not different between patients and controls. However, a significant difference was found for anti-tTG IgG antibodies. Even if both in controls and in patients the mean anti-tTG IgG value was below the cutoff, the estimates produced by the statistical model showed that each unit increase in the anti-tTG IgG antibody value corresponded to an approximately 5% increased chance of having a mood disorder. The patient group showed a more frequent presence of symptoms associated to non-celiac gluten sensitivity. However, as there was neither any correlation between antibody levels and gastrointestinal symptoms, nor with the intensity of the psychiatric symptoms, it may be conceivable that the increase in anti-tTG IgG antibodies is not disorder-related but possibly an outcome of the psychiatric disorder itself