Project description:Head and neck squamous cell carcinoma (HNSCC) is a deadly and disfiguring disease for which better systemic therapy is desperately needed. The development of new therapies for HNSCC and the understanding of its biology both depend upon clinically relevant animal models. An increasingly promising xenograft model, the patient derived xenograft (PDX), is developed by surgically implanting tumor tissue directly from a patient into an immunocompromised mouse. We transplanted 30 HNSCC primary tumors directly into mice. The histology and stromal components were analyzed using immunohistochemistry. Gene expression analysis with Affymetrix U133A-microarrays was conducted on patient tumors, including third generation and one tenth generation PDX; one PDX-derived cell line; and 2 established HNSCC cell lines. Five of 30 (17%) transplanted tumors could be serially passaged and used for therapeutic and mechanistic studies. One cell line has been established from a tongue primary. The tumors maintained the histologic appearance of the parent tumor although human stromal components were lost upon engraftment. One PDX model was derived from an HPV-positive tumor. From the >54,000 probes tested, there were widespread differences in gene expression between the tumors growing in mice vs. the corresponding human tumors from which they were derived. For genes differing between parent tumors and human cell lines in culture, the PDXs’ expression pattern was very similar to that of the parent tumors. There were also widespread expression differences between the human tumors that subsequently grew in mice vs. those that did not - suggesting that this model enriches for cancers with distinct biological features. Our results demonstrate the feasibility of a PDX model of HNSCC. Gene expression patterns suggest that the PDX more closely recapitulated the parental tumor than do cells in culture. The histology of the tumors in mice is similar to that of the same tumor in humans. Additionally, gene expression patterns and histology are stable over multiple generations. We transplanted HNSCC primary tumors directly into mice. Gene expression analysis with Affymetrix U133A-microarrays was conducted on patient tumors, including third generation and one tenth generation PDX; one PDX-derived cell line; and 2 established HNSCC cell lines.

Project description:Head and neck squamous cell carcinoma (HNSCC) is a deadly and disfiguring disease for which better systemic therapy is desperately needed. The development of new therapies for HNSCC and the understanding of its biology both depend upon clinically relevant animal models. An increasingly promising xenograft model, the patient derived xenograft (PDX), is developed by surgically implanting tumor tissue directly from a patient into an immunocompromised mouse. We transplanted 30 HNSCC primary tumors directly into mice. The histology and stromal components were analyzed using immunohistochemistry. Gene expression analysis with Affymetrix U133A-microarrays was conducted on patient tumors, including third generation and one tenth generation PDX; one PDX-derived cell line; and 2 established HNSCC cell lines. Five of 30 (17%) transplanted tumors could be serially passaged and used for therapeutic and mechanistic studies. One cell line has been established from a tongue primary. The tumors maintained the histologic appearance of the parent tumor although human stromal components were lost upon engraftment. One PDX model was derived from an HPV-positive tumor. From the >54,000 probes tested, there were widespread differences in gene expression between the tumors growing in mice vs. the corresponding human tumors from which they were derived. For genes differing between parent tumors and human cell lines in culture, the PDXs’ expression pattern was very similar to that of the parent tumors. There were also widespread expression differences between the human tumors that subsequently grew in mice vs. those that did not - suggesting that this model enriches for cancers with distinct biological features. Our results demonstrate the feasibility of a PDX model of HNSCC. Gene expression patterns suggest that the PDX more closely recapitulated the parental tumor than do cells in culture. The histology of the tumors in mice is similar to that of the same tumor in humans. Additionally, gene expression patterns and histology are stable over multiple generations.

Project description:Engraftment of primary pancreas ductal adenocarcinomas (PDAC) in mice to generate patient derived xenograft (PDX) models is a promising platform to for biological and therapeutic studies in this disease. However, these models are still incompletely characterized. Here, we measured the impact of the murine environment on the gene expression of the engrafted human tumoral cells. We have analyzed gene expression profiles from 35 new PDX models and compared them with previously published microarray data from PDAC and hepatocellular carcinoma (HCC). Our results showed that PDX models derived from PDAC, or HCC, were clearly different to the cell lines derived from the same cancer tissues. Indeed, PDAC- and HCC-derived cell lines are indistinguishable one from the other based in their gene expression profiles. In contrast, the transcriptomes of PDAC and HCC PDX models are clearly different and more similar to their original tumor than to PDX models from the other tumor type. Interestingly, the main differences between pancreatic PDX models and human PDAC is the expression of genes involved in pathways related with extracellular matrix interactions and cell cycle regulation likely reflecting the adaptations of the tumors to the new environment. Furthermore, most of these differences are detected in the first passages after the tumor engraftment, indicating early phases of the adaptation process. In conclusion, different from conventional cancer cell lines, PDX models of PDAC retain similar gene expression profiles of PDAC. Expression changes are mainly related to genes involved in stromal pathways likely reflecting the adaptation to new environments. We also provide evidence of the stability of gene expression patterns over subsequent passages. We have analyzed gene expression profiles from 35 new PDX models and compared them with previously published in GEO microarray data. We used PDX models, primary tumors and cell lines from PDAC and hepatocellular carcinoma. All these public data were re-process in order to compare with our 35 samples

Project description:Osteosarcoma (OS) and Ewing’s sarcoma (EW) are the two most common pediatric solid tumors, after brain tumors. Multimodal treatments have significantly improved prognosis in localized disease but outcome is still poor in metastatic patients, for whom therapeutic options are often inadequate. Preclinical drug testing to identify promising treatment options that match the molecular make-up of these tumors is hampered by the lack of appropriate and molecularly well-characterized patient-derived models. To address this need, a panel of patient-derived xenografts (PDX) was established by subcutaneous implantation of fresh, surgically resected OS and EW tumors in NSG mice. Tumors were re-transplanted to next mice generations and fragments were collected for histopathological and molecular characterization. A model was considered established after observing stable histological and molecular features for at least three passages. To evaluate the similarity of the model with primary tumor, we performed a global gene expression profiling and tissue microarrays (TMA), to assess tumor specific biomarkers on tissues from OS/EW tumors and their PDXs (1st and 3rd passage). Moreover, we verified the feasibility of these models for preclinical drug testing. We implanted 61 OS and 29 EW samples: 14/38 (37%) primary OS and 9/23 (39%) OS lung metastases successfully engrafted; while among EW, 5/26 (19%) primary samples and 1/3 (33%) metastases were established. Comparison between patient samples and PDXs, highlighted that histology and genetic characteristics of PDXs were stable and maintained over passages. In particular, correlative analysis between OS and EW samples and their PDXs was extremely high (Pearson’s r range r=0.94-0.96), while patient-derived primary cultures displayed reduced correlation with human samples (r=0.90-0.93), indicating that in vitro adaptation superimpose molecular alterations that create genetic diversion from original tumors. No significant differentially expressed gene profile was observed from the comparison between EW samples and PDXs (fold change > 2, adjusted p <0.05 at paired t-test). In OS, the comparison between OS patient-derived tumors and PDX indicated differences in 397 genes, mostly belonging to immune system functional category. This is in line with the idea that human immune cells are gradually replaced by murine counterparts upon engraftment in the mouse. As proof-of concept, two EW PDX and one OS PDX have been treated with conventional and innovated drugs to test their value in terms of drug-sensitivity prediction. Overall, our study indicated that PDX models maintained the histological and genetic markers of the tumor samples and represent reliable models to test sensitivity to novel drug associations.

Project description:Triple negative breast cancer (TNBC) is an aggressive subtype of breast cancer, with approximately 50% of patients having residual disease after neoadjuvant chemotherapy (NACT) and worse prognosis with higher residual cancer burden (RCB). Patient-derived xenograft (PDX) models of breast cancer are an effective discovery platform and tool for preclinical pharmacologic testing and biomarker identification. There is a need for PDX models encompassing the heterogeneity of TNBC both pre- and post- therapy and for identifying clinical and molecular features of patient’s tumors that are associated with success in establishing these models. Using fine-needle aspirates (FNAs), we established orthotopic PDX models of TNBC from the primary breast tumors of patients prior to and following neoadjuvant systemic therapy while enrolled in the ARTEMIS trial (NCT02276443). ARTEMIS is a prospective neoadjuvant clinical trial for women with primary TNBC who are treated with four cycles of Adriamycin combined with cyclophosphamide (AC) followed by taxane +/- different experimental therapies. Serial biopsies were obtained from patients prior to treatment (pre-therapy), from poorly responsive disease after four cycles of AC (mid-NACT), and in cases of AC-resistance, after a three-month course of different experimental therapies and/or additional chemotherapy (post-NACT). Our study cohort includes a total of 269 FNA biopsies from 217 women, generating a total of 62 successful PDX models (overall success-rate = 23%). This cohort includes five serial pre- and mid-NACT PDX pairs, as well as one serial pre-, mid-, post-NACT triplet. Success of PDX engraftment was generally higher from cancers that proved to be treatment-resistant: whether poor response to AC determined by ultrasound measurements mid-NACT (p=0.063), RCB II/III status after NACT (p=0.046), or metastatic relapse within two years of surgery (p=0.008). TNBC molecular subtype determined from gene expression microarrays of pre-NACT tumor revealed no significant association with PDX engraftment rate (p=0.877). Finally, we developed a statistical model predictive of PDX engraftment using percent Ki67 positive cells in the patient’s diagnostic biopsy, positive lymph node status at diagnosis, and low volumetric reduction of the patient’s tumor following AC treatment. This novel bank of 62 PDX models of TNBC provides a valuable resource for biomarker discovery and preclinical therapeutic trials aimed at improving neoadjuvant response rates for patients with TNBC.

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Targeted sequencing of head and neck squamous cell carcinomas

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