Layer-by-Layer Analysis of In Vitro Skin Models

In vitro human skin models are evolving into versatile platforms for the study of skin biology and disorders. These models have many potential applications in the fields of drug testing and safety assessment, as well as cosmetic and new treatment development. The development of in vitro skin models that accurately mimic native human skin can reduce reliance on animal models and also allow for more precise, clinically relevant testing. Recent advances in biofabrication techniques and biomaterials have led to the creation of increasingly complex, multilayered skin models that incorporate important functional components of skin, such as the skin barrier, mechanical properties, pigmentation, vasculature, hair follicles, glands, and subcutaneous layer. This improved ability to recapitulate the functional aspects of native skin enhances the ability to model the behavior and response of native human skin, as the complex interplay of cell-to-cell and cell-to-material interactions are incorporated. In this review, we summarize the recent developments in in vitro skin models, with a focus on their applications, limitations, and future directions.

Compound shougong powder inhibits the malignant phenotype of hepatocellular carcinoma cells by targeting the DNA damage repair pathway

OBJECTIVES

Compound Shougong Powder (SGS), a traditional Chinese medicine formulation, has been used to treat cancer for many years with remarkable efficacy. However, the mechanisms underlying the therapeutic effect of SGS in Hepatocellular carcinoma (HCC) are not completely clear.

METHODS

The survival and metastasis of HCC cells were examined by CCK-8 assay, EdU assay, Wound-healing and Transwell assay. The anti-tumour effect of SGS was studied using hoechst 33258 staining and flow cytometry. RNA sequencing was applied to detect the underlying mechanism. Comet DNA, qRT-PCR and WB experiments were performed for validation. In addition, HCC nude mouse model was constructed to detect SGS effect in vivo.

KEY FINDINGS

SGS inhibited the proliferation, migration and invasion of HCC cells and induced apoptosis in vitro. In addition, SGS also suppressed tumour growth in a nude mouse model of HCC in a dose-dependent manner. RNA sequencing of the suitably treated HCC cells revealed significant changes in the expression levels of genes involved in the DNA damage repair pathway. The sequencing results were verified by Comet DNA, qRT-PCR, WB assays and molecular docking.

CONCLUSIONS

Taken together, SGS inhibits the malignant phenotype of HCC cells by down-regulating DNA repair genes and consequently inducing DNA damage.

Patient-derived orthotopic xenograft (PDOX) nude mouse model of soft-tissue sarcoma more closely mimics the patient behavior in contrast to the subcutaneous ectopic model

AIM

Soft-tissue sarcomas are a group of rare mesenchymal carcinomas that include approximately 50 histological types, and account for 1% of all adult cancer cases. The yearly incidence of soft-tissue sarcomas in the USA is approximately 11,280 cases, with an overall mortality of 3,900 deaths per year.

MATERIALS AND METHODS

In this study, we established a patient-derived orthotopic xenograft (PDOX) from a patient with a soft-tissue sarcoma of the retroperitoneum in nude mice and compared it to a subcutaneous patient-derived model of the same tumor for histology.

RESULTS

In the PDOX model, a bulky tumor grew in the left retroperitoneum in the same manner as the patient's tumor. Upon histological examination, the majority of the PDOX tissue section comprised sarcomatous high-grade spindle cells of varying sizes, similar to the original patient tumor. In contrast, the majority of the subcutaneously-implanted tumor comprised round to oval cells.

CONCLUSION

These results indicate that the PDOX recapitulated the histology of the original tumor more than the subcutaneous model.