Patient-Derived Xenograft Models in Cervical Cancer: A Systematic Review

Background: Patient-derived xenograft (PDX) models have been a focus of attention because they closely resemble the tumor features of patients and retain the molecular and histological features of diseases. They are promising tools for translational research. In the current systematic review, we identify publications on PDX models of cervical cancer (CC-PDX) with descriptions of main methodological characteristics and outcomes to identify the most suitable method for CC-PDX. Methods: We searched on PubMed to identify articles reporting CC-PDX. Briefly, the main inclusion criterion for papers was description of PDX created with fragments obtained from human cervical cancer specimens, and the exclusion criterion was the creation of xenograft with established cell lines. Results: After the search process, 10 studies were found and included in the systematic review. Among 98 donor patients, 61 CC-PDX were established, and the overall success rate was 62.2%. The success rate in each article ranged from 0% to 75% and was higher when using severe immunodeficient mice such as severe combined immunodeficient (SCID), nonobese diabetic (NOD) SCID, and NOD SCID gamma (NSG) mice than nude mice. Subrenal capsule implantation led to a higher engraftment rate than orthotopic and subcutaneous implantation. Fragments with a size of 1–3 mm3 were suitable for CC-PDX. No relationship was found between the engraftment rate and characteristics of the tumor and donor patient, including histology, staging, and metastasis. The latency period varied from 10 days to 12 months. Most studies showed a strong similarity in pathological and immunohistochemical features between the original tumor and the PDX model. Conclusion: Severe immunodeficient mice and subrenal capsule implantation led to a higher engraftment rate; however, orthotopic and subcutaneous implantation were alternatives. When using nude mice, subrenal implantation may be better. Fragments with a size of 1–3 mm3 were suitable for CC-PDX. Few reports have been published about CC-PDX; the results were not confirmed because of the small sample size.

Subrenal capsule (SRC) implantation of tumor tissue v1

This protocol describes the steps required for the successful implantation of tumor tissues under the subrenal capsule. The subrenal capsule is an optimum site for the propagation of tumor tissue as it provides an environment rich with blood vessels and growth factors.

Extracellular Matrix Induces Periodontal Ligament Reconstruction In Vivo

One of the problems in dental implant treatment is the lack of periodontal ligament (PDL), which supports teeth, prevents infection, and transduces sensations such as chewiness. The objective of the present study was to develop a decellularized PDL for supporting an artificial tooth. To this end, we prepared mouse decellularized mandible bone with a PDL matrix by high hydrostatic pressure and DNase and detergent treatments and evaluated its reconstruction in vivo. After tooth extraction, the decellularized mandible bone with PDL matrix was implanted under the subrenal capsule in rat and observed that host cells migrated into the matrix and oriented along the PDL collagen fibers. The extracted decellularized tooth and de- and re-calcified teeth, which was used as an artificial tooth model, were re-inserted into the decellularized mandible bone and implanted under the subrenal capsule in rat. The reconstructed PDL matrix for the extracted decellularized tooth resembled the decellularized mandible bone without tooth extraction. This demonstrates that decellularized PDL matrix can reconstruct PDL tissue by controlling host cell migration, which could serve as a novel periodontal treatment approach.

Establishment of Patient-Derived Tumor Xenograft Models of High-Risk Endometrial Cancer

ObjectiveHigh-risk endometrial cancers (ECs), including high-grade EC, serous carcinoma (SC), clear cell carcinoma, and carcinosarcoma, account for 50% of deaths due to ECs. Therapies for these cancers are limited, and patient-derived tumor xenograft (PDTX) models are useful tools for preclinical drug evaluation, biomarker identification, and personalized medicine strategies. Here, we used and compared 2 methods to establish PDTX models.MethodsFresh tumor tissues collected from 18 primary high-risk EC patients (10 high-grade ECs, 6 SCs, 1 clear cell carcinoma, and 1 carcinosarcoma) were engrafted subcutaneously and in the subrenal capsule in NOD/SCID for establishment and Balb/c-nu/nu mice for expansion. Histology and cytokeratin, estrogen receptor, progesterone receptor, and P53 expression were evaluated to assess the similarity of primary tumors and different generations of PDTX tumors. Whole-exome sequencing (WES) and RNA sequencing were used in 2 high-grade EC models to verify whether the genetic mutation profiles and gene expression were similar between primary and PDTX tumors.ResultsThe total tumor engraftment rate was 77.8% (14/18) regardless of the engraft method. The tumor engraftment rate was increased in subrenal capsule models compared with subcutaneous models (62.5% vs 50%, P = 0.464). The time to tumor formation varied significantly from 2 to 11 weeks. After subrenal capsular grafting, grafted tumors could be successfully transplanted to subcutaneous sites. We observed good similarity between primary tumors and corresponding different passages of xenografts.ConclusionsThe combination of 2 engrafting methods increases the tumor engraftment rate. The high tumor engraftment rate ensures the establishment of a high-risk EC biobank, which is a powerful resource for performing preclinical drug-sensitivity tests and identifying biomarkers for response or resistance.

An Aqueous Extract of Marine Microalgae Exhibits Antimetastatic Activity through Preferential Killing of Suspended Cancer Cells and Anticolony Forming Activity

Research on marine natural products as potential anticancer agents is still limited. In the present study, an aqueous extract of a Canadian marine microalgal preparation was assessed for anticancer activities using various assays and cell lines of human cancers, including lung, prostate, stomach, breast, and pancreatic cancers, as well as an osteosarcoma.In vitro, the microalgal extract exhibited marked anticolony forming activity. In addition, it was more toxic, as indicated by increased apoptosis, to nonadherent cells (grown in suspension) than to adherent cells.In vivo, an antimetastatic effect of the extract was observed in NOD-SCID mice carrying subrenal capsule xenografts of PC3 prostate cancer cells. The results of the present study suggest that the antimetastatic effect of the aqueous microalgal extract is based on inhibition of colony forming ability of cancer cells and the preferential killing of suspended cancer cells. Further research aimed at identification of the molecular basis of the anticancer activities of the microalgal extract appears to be warranted.

Use of an optimized primary ovarian cancer xenograft model to mimic patient tumor biology and heterogeneity.

5036 Background: Current xenograft and transgenic models of ovarian cancer are mainly homogeneous and poorly predict response to therapy. Use of patient tumors may represent a better model for tumor biology and offer potential to test personalized medicine approaches, but poor take rates and questions of recapitulation of patient tumors have limited this approach. We have developed a protocol for improved feasibility of such a model and examined its similarity to the patient tumor. Methods: Under IRB and IACUC approval, 23 metastatic ovarian cancer samples were collected at the time of tumor reductive surgery. Samples were implanted either subcutaneously (SQ), intraperitoneally (IP), in the mammary fat pad (MFP), or in the subrenal capsule (SRC) and monitored for tumor growth. Cohorts from 8 xenolines were treated with combined carboplatin and paclitaxel or vehicle, and response to therapy compared between xenografts and patients. Expression of tumor-initiating cell (TIC) markers ALDH1, CD133, and CD44 was assessed by immunohistochemistry in tumors from patients and treated and untreated xenografts. Results: At least one SQ implanted tumor developed in 91.3% of xenografts, significantly higher than in the MFP (63.6%), IP (23.5%), or SRC (8%). Xenografts were similar in expression of putative TIC’s compared to patient tumors. The patients and the xenografts also have similar responses to chemotherapy in that xenografts from patients with a partial response responded more slowly than those from patients achieving a complete response (45 vs 21 days, p=.004). Treated xenografts were more densely composed of TICs. ALDH1 increased to 36.1% from 16.2% (p=0.002) and CD133 increased to 33.8% from 16.2% (p=0.026). Conclusions: Xenoline development can be achieved at a high rate when tumors collected from metastatic sites are implanted SQ. These xenografts are similar to patient tumors with regard to chemotherapy response and TIC expression.. This model may be a more accurate model for in vivo pre-clinical studies as compared to current models. Also, as treated xenografts become chemoresistant, this model is well positioned to evaluate targeted therapies aimed at the most aggressive populations in a heterogeneous tumor.