Project description:Background and aimsHepatoblastoma (HBL) is a devastating pediatric liver cancer with multiple treatment options, but it ultimately requires surgery for a cure. The most malicious form of HBL is a chemo-resistant aggressive tumor that is characterized by rapid growth, metastases, and poor response to treatment. Very little is known of the mechanisms of aggressive HBL, and recent focuses have been on developing alternative treatment strategies. In this study, we examined the role of human chromosomal regions, called aggressive liver cancer domains (ALCDs), in liver cancer and evaluated the mechanisms that activate ALCDs in aggressive HBL.ResultsWe found that ALCDs are critical regions of the human genome that are located on all human chromosomes, preferentially in intronic regions of the oncogenes and other cancer-associated genes. In aggressive HBL and in patients with Hepatocellular (HCC), JNK1/2 phosphorylates p53 at Ser6, which leads to the ph-S6-p53 interacting with and delivering the poly(adenosine diphosphate ribose) polymerase 1 (PARP1)/Ku70 complexes on the oncogenes containing ALCDs. The ph-S6-p53-PARP1 complexes open chromatin around ALCDs and activate multiple oncogenic pathways. We found that the inhibition of PARP1 in patient-derived xenografts (PDXs) from aggressive HBL by the Food and Drug Administration (FDA)-approved inhibitor olaparib (Ola) significantly inhibits tumor growth. Additionally, this is associated with the reduction of the ph-S6-p53/PARP1 complexes and subsequent inhibition of ALCD-dependent oncogenes. Studies in cultured cancer cells confirmed that the Ola-mediated inhibition of the ph-S6-p53-PARP1-ALCD axis inhibits proliferation of cancer cells.ConclusionsIn this study, we showed that aggressive HBL is moderated by ALCDs, which are activated by the ph-S6-p53/PARP1 pathway. By using the PARP1 inhibitor Ola, we suppressed tumor growth in HBL-PDX models, which demonstrated its utility in future clinical models.
Project description:BackgroundThe search for biomarkers to evaluate ovarian cancer (OC) homologous recombination (HR) function and predict the response to therapy is an urgent clinical need to improve the selection of patients who could benefit from platinum- and olaparib (poly-ADP ribose polymerase inhibitors, PARPi)-based therapies.MethodsWe used a large collection of OC patient-derived xenografts (PDXs) (n = 47) and evaluated their HR status based on BRCA1/2 mutations, BRCA1 promoter methylation and the HRDetect score. RAD51 foci were quantified in formalin-fixed, paraffin-embedded untreated tumour specimens by immunofluorescence and the messenger RNA expression of 21 DNA repair genes by real-time PCR.ResultsTumour HR deficiency predicted both platinum and olaparib responses. The basal level of RAD51 foci evaluated in geminin-positive/replicating cells strongly inversely correlated with olaparib response (p = 0.011); in particular, the lower the foci score, the greater the sensitivity to olaparib, while low RAD51 foci score seems to associate with platinum activity.ConclusionsThe basal RAD51 foci score is a candidate predictive biomarker of olaparib response in OC patients as it can be easily translatable in a clinical setting. Moreover, the findings corroborate the importance of OC-PDXs as a reliable tool to identify and validate biomarkers of response to therapy.
Project description:PurposeTo determine the ability of RAD51 foci to predict platinum chemotherapy response in high-grade serous ovarian cancer (HGSOC) patient-derived samples.Experimental designRAD51 and γH2AX nuclear foci were evaluated by immunofluorescence in HGSOC patient-derived cell lines (n = 5), organoids (n = 11), and formalin-fixed, paraffin-embedded tumor samples (discovery n = 31, validation n = 148). Samples were defined as RAD51-High if >10% of geminin-positive cells had ≥5 RAD51 foci. Associations between RAD51 scores, platinum chemotherapy response, and survival were evaluated.ResultsRAD51 scores correlated with in vitro response to platinum chemotherapy in established and primary ovarian cancer cell lines (Pearson r = 0.96, P = 0.01). Organoids from platinum-nonresponsive tumors had significantly higher RAD51 scores than those from platinum-responsive tumors (P < 0.001). In a discovery cohort, RAD51-Low tumors were more likely to have a pathologic complete response (RR, 5.28; P < 0.001) and to be platinum-sensitive (RR, ∞; P = 0.05). The RAD51 score was predictive of chemotherapy response score [AUC, 0.90; 95% confidence interval (CI), 0.78-1.0; P < 0.001). A novel automatic quantification system accurately reflected the manual assay (92%). In a validation cohort, RAD51-Low tumors were more likely to be platinum-sensitive (RR, ∞; P < 0.001) than RAD51-High tumors. Moreover, RAD51-Low status predicted platinum sensitivity with 100% positive predictive value and was associated with better progression-free (HR, 0.53; 95% CI, 0.33-0.85; P < 0.001) and overall survival (HR, 0.43; 95% CI, 0.25-0.75; P = 0.003) than RAD51-High status.ConclusionsRAD51 foci are a robust marker of platinum chemotherapy response and survival in ovarian cancer. The utility of RAD51 foci as a predictive biomarker for HGSOC should be tested in clinical trials.
Project description:Mucinous ovarian carcinoma (mEOC) represents a rare subtype of epithelial ovarian cancer, accounting for 3-4% of all ovarian carcinomas. The rarity of this tumor type renders both the preclinical and clinical research compelling. Very few preclinical in vitro and in vivo models exist. We here report the molecular, metabolic and pharmacological characterization of two patient derived xenografts (PDXs) from mEOC, recently obtained in our laboratory. These PDXs maintain the histological and molecular characteristics of the patient's tumors they derived from, including a wild type TP53. Gene expression analysis and metabolomics profile suggest that they differ from high grade serous/endometrioid ovarian carcinoma PDXs. The pharmacological characterization was undertaken testing the in vivo antitumor activity of both cytotoxic agents (cisplatin, paclitaxel, yondelis, oxaliplatin and 5-fluorouracile) and targeted agents (bevacizumab and lapatinib). These newly established mucinous PDXs do recapitulate mEOC and will be of value in the preclinical development of possible new therapeutic strategies for this tumor type.
Project description:PurposePatient-derived tumor xenografts (PDXs) can provide more reliable information about tumor biology than cell line models. We developed PDXs for epithelial ovarian cancer (EOC) that have histopathologic and genetic similarities to the primary patient tissues and evaluated their potential for use as a platform for translational EOC research.Materials and methodsWe successfully established PDXs by subrenal capsule implantation of primary EOC tissues into female BALB/C-nude mice. The rate of successful PDX engraftment was 48.8% (22/45 cases). Hematoxylin and eosin staining and short tandem repeat analysis showed histopathological and genetic similarity between the PDX and primary patient tissues.ResultsPatients whose tumors were successfully engrafted in mice had significantly inferior overall survival when compared with those whose tumors failed to engraft (p=0.040). In preclinical tests of this model, we found that paclitaxel-carboplatin combination chemotherapy significantly deceased tumor weight in PDXs compared with the control treatment (p=0.013). Moreover, erlotinib treatment significantly decreased tumor weight in epidermal growth factor receptor-overexpressing PDX with clear cell histology (p=0.023).ConclusionPDXs for EOC with histopathological and genetic stability can be efficiently developed by subrenal capsule implantation and have the potential to provide a promising platform for future translational research and precision medicine for EOC.
Project description:PurposeRecurrence and chemoresistance (CR) are the leading causes of death in patients with high-grade serous carcinoma (HGSC) of the ovary. The aim of this study was to identify genetic changes associated with CR mechanisms using a patient-derived xenograft (PDX) mouse model and genetic sequencing.Materials and methodsTo generate a CR HGSC PDX tumor, mice bearing subcutaneously implanted HGSC PDX tumors were treated with paclitaxel and carboplatin. We compared gene expression and mutations between chemosensitive (CS) and CR PDX tumors with whole exome and RNA sequencing and selected candidate genes. Correlations between candidate gene expression and clinicopathological variables were explored using the Cancer Genome Atlas (TCGA) database and the Human Protein Atlas (THPA).ResultsThree CR and four CS HGSC PDX tumor models were successfully established. RNA sequencing analysis of the PDX tumors revealed that 146 genes were significantly up-regulated and 54 genes down-regulated in the CR group compared with the CS group. Whole exome sequencing analysis showed 39 mutation sites were identified which only occurred in CR group. Differential expression of SAP25, HLA-DPA1, AKT3, and PIK3R5 genes and mutation of TMEM205 and POLR2A may have important functions in the progression of ovarian cancer chemoresistance. According to TCGA data analysis, patients with high HLA-DPA1 expression were more resistant to initial chemotherapy (p=0.030; odds ratio, 1.845).ConclusionWe successfully established CR ovarian cancer PDX mouse models. PDX-based genetic profiling study could be used to select some candidate genes that could be targeted to overcome chemoresistance of ovarian cancer.
Project description:Ovarian cancer is the most lethal gynecologic malignancy. About 75% of ovarian cancer patients relapse and/or develop chemo-resistant disease after initial response to standard-of-care treatment with platinum-based therapies. HER2 amplifications and overexpression in ovarian cancer are reported to vary, and responses to HER2 inhibitors have been poor. Next generation sequencing technologies in conjunction with testing using patient-derived xenografts (PDX) allow validation of personalized treatments. Using a whole-genome mate-pair next generation sequencing (MPseq) protocol, we identified several high grade serous ovarian cancers (HGS-OC) with DNA alterations in genes encoding members of the ERBB2 pathway. The efficiency of anti-HER2 therapy was tested in three different PDX lines with the identified alterations and high levels of HER2 protein expression. Treatment responses to pertuzumab or pertuzumab/trastuzumab were compared in each PDX line WITH standard carboplatin and paclitaxel combination treatment. In all three PDX models, HER2-targeted therapy resulted in significant inhibition of tumor growth compared with untreated controls. However, the responses in each case were inferior to those to chemotherapy, even for chemo-resistant lines. When chemotherapy and HER2-targeted therapy were administered together, a significant regression of tumor was observed after 6 weeks of treatment compared with chemotherapy alone. Post-treatment analysis of these tissues revealed that inhibition of the ERBB2 pathway occurred at the level of phosphorylation and expression of downstream targets. In conclusion, while targeting of presumably activated ERBB2 pathway alone in HGS-OC results in a modest treatment benefit, a combination therapy including both chemotherapy drugs and HER2 inhibitors provides a far better response. Further studies are needed to address development of recurrence and sensitivity of recurrent disease to HER2-targeted therapy.
Project description:BackgroundOlaparib has single-agent activity against breast/ovarian cancer (BrCa/OvCa) in germline BRCA1 or BRCA2 mutation carriers (gBRCAm). We hypothesized addition of olaparib to carboplatin can be administered safely and yield preliminary clinical activity.MethodsEligible patients had measurable or evaluable disease, gBRCAm, and good end-organ function. A 3 + 3 dose escalation tested daily oral capsule olaparib (100 or 200mg every 12 hours; dose level1 or 2) with carboplatin area under the curve (AUC) on day 8 (AUC3 day 8), then every 21 days. For dose levels 3 to 6, patients were given olaparib days 1 to 7 at 200 and 400 mg every 12 hours, with carboplatin AUC3 to 5 on day 1 or 2 every 21 days; a maximum of eight combination cycles were permitted, after which daily maintenance of olaparib 400mg every12 hours continued until progression. Dose-limiting toxicity was defined in the first two cycles. Peripheral blood mononuclear cells were collected for polymorphism analysis and polyADP-ribose incorporation. Paired tumor biopsies (before/after cycle 1) were obtained for biomarker proteomics and apoptosis endpoints.ResultsForty-five women (37 OvCa/8 BrCa) were treated. Dose-limiting toxicity was not reached on the intermittent schedule. Expansion proceeded with olaparib 400mg every 12 hours on days 1 to 7/carboplatin AUC5. Grade 3/4 adverse events included neutropenia (42.2%), thrombocytopenia (20.0%), and anemia (15.6%). Responses included 1 complete response (1 BrCa; 23 months) and 21 partial responses (50.0%; 15 OvCa; 6 BrCa; median = 16 [4 to >45] in OvCa and 10 [6 to >40] months in BrCa). Proteomic analysis suggests high pretreatment pS209-eIF4E and FOXO3a correlated with duration of response (two-sided P < .001; Pearson's R (2) = 0.94).ConclusionsOlaparib capsules 400mg every 12 hours on days 1 to 7/carboplatin AUC5 is safe and has activity in gBRCAm BrCa/OvCa patients. Exploratory translational studies indicate pretreatment tissue FOXO3a expression may be predictive for response to therapy, requiring prospective validation.
Project description:- Within ovarian cancer research, patient-derived xenograft (PDX) models recapitulate histologic features and genomic aberrations found in original tumors. However, conflicting data from published studies have demonstrated significant transcriptional differences between PDXs and original tumors, which challenges the fidelity of these models. We employed a quantitative mass spectrometry-based proteomic approach coupled with the generation of patient-specific databases using RNA-seq data to investigate the proteogenomic landscape of serially-passaged PDX models established from two patients with distinct subtypes of ovarian cancer.
Project description:PurposeBRCA1/BRCA2 predictive test negatives are proven noncarriers of a BRCA1/BRCA2 mutation that is carried by their relatives. The risk of developing breast cancer (BC) or epithelial ovarian cancer (EOC) in these women is uncertain. The study aimed to estimate risks of invasive BC and EOC in a large cohort of BRCA1/BRCA2 predictive test negatives.MethodsWe used cohort analysis to estimate incidences, cumulative risks, and standardized incidence ratios (SIRs).ResultsA total of 1,895 unaffected women were eligible for inclusion in the BC risk analysis and 1,736 in the EOC risk analysis. There were 23 incident invasive BCs and 2 EOCs. The cumulative risk of invasive BC was 9.4% (95% confidence interval (CI) 5.9-15%) by age 85 years and the corresponding risk of EOC was 0.6% (95% CI 0.2-2.6%). The SIR for invasive BC was 0.93 (95% CI 0.62-1.40) in the overall cohort, 0.85 (95% CI 0.48-1.50) in noncarriers from BRCA1 families, and 1.03 (95% CI 0.57-1.87) in noncarriers from BRCA2 families. The SIR for EOC was 0.79 (95% CI 0.20-3.17) in the overall cohort.ConclusionOur results did not provide evidence for elevated risks of invasive BC or EOC in BRCA1/BRCA2 predictive test negatives.