Establishment of humanised xenograft models as in vivo study for lung metastasis of osteosarcoma.

Humanised xenograft models and cancer cell lines are widely used for preclinical drug evaluation, biological studies, and targeted therapy strategies in cancer research. A humanised mouse model is a laboratory mouse that has been genetically modified to contain specific human genes, cells, or tissues. By introducing human-specific elements into rodents, researchers can create a more accurate representation of human physiological and pathological processes. Lacking an appropriate animal model for osteosarcoma (OS), hindered understanding of underlying mechanisms in OS metastasis progression. Markedly, metastasis influences the prognosis and treatment of osteosarcoma. Gaining insight into the mechanisms and occurrences of metastasis could potentially facilitate oncologists in improving therapies. Hence, it is important to develop a lung metastatic OS model to study the basic biology of its progression. This study has established a tumour-bearing mouse model using HOS-143B cell line which was injected into male NOD.SCID gamma (NSG) mice at two locations; intramuscularly (hind leg) and subcutaneously (back) respectively. The primary and metastatic tumour size was monitored by palpating the area of tumour induced and quantified using digital calliper. H&E staining was performed by pathologist to confirm metastasis. Our results showed that mice injected with 1 million cancer cells were unable to produce tumours. Meanwhile, mice injected with three million cancer cells showed tumour development and lung metastasis after 25 days of cancer cell inoculation. In conclusion, this study has successfully established a lung metastatic OS mouse model that could be useful for biological studies of OS. These findings imply that this model is essential for safety and efficacy before clinical trials, accelerate the translation from basic research to therapeutic applications.

Leptin-induced increase in blood pressure and markers of endothelial activation during pregnancy in Sprague Dawley rats is prevented by resibufogenin, a marinobufagenin antagonist.

Levels of leptin and marinobufagenin (MBG), a cardiotonic steroid, are elevated in the serum of women with pre-eclampsia. Besides this, leptin administration to pregnant rats increases systolic blood pressure (SBP), urinary protein excretion and serum markers of endothelial activation. The link between leptin and MBG is unknown and it is also unclear if leptin-induced increases in blood pressure and proteinuria in the pregnant rat could be prevented by an MBG antagonist. To ascertain this link, this study investigated the effect of resibufogenin (RBG), a marinobufagenin antagonist, on leptin-induced increases in blood pressure and proteinuria during pregnancy in rats. Four groups of Sprague-Dawley rats, aged 12 weeks, were given either normal saline (CONTROL) or 120 µg/kg/day of leptin (LEP), or 120 µg/kg/day of leptin+30 µg/kg/day of resibufogenin (L + RBG) or 30 µg/kg/day of resibufogenin (RBG) from Day 1-20 of pregnancy. Systolic blood pressure and urinary protein excretion (UPE) were measured during the study period. Animals were euthanized on day 21 of pregnancy and vascular cell adhesion molecule 1, (VCAM-1), soluble intracellular cell adhesion molecule 1 (sICAM-1), E-selectin and endothelin-1 (ET-1) were estimated in the serum. SBP, UPE, VCAM-1, sICAM-1 and ET-1 were significantly higher only in the LEP group when compared with those in CONT and in L + RBG and RBG groups. The prevention by RBG of leptin-induced increases in SBP, proteinuria, and endothelial activation during pregnancy seem to suggest a potential role for MBG in leptin-induced adverse effects on blood pressure, urinary protein excretion and endothelial activity during pregnancy in the rat.

Investigating the role of the IGF axis as a predictor of biochemical recurrence in prostate cancer patients post-surgery.

BACKGROUND: Between 20% and 35% of prostate cancer (PCa) patients who undergo treatment with curative intent (ie, surgery or radiation therapy) for localized disease will experience biochemical recurrence (BCR). Alterations in the insulin-like growth factor (IGF) axis and PTEN expression have been implicated in the development and progression of several human tumors including PCa. We examined the expression of the insulin receptor (INSR), IGF-1 receptor (IGF-1R), PTEN, and AKT in radical prostatectomy tissue of patients who developed BCR post-surgery. METHODS: Tissue microarrays (TMA) of 130 patients post-radical prostatectomy (65 = BCR, 65 = non-BCR) were stained by immunohistochemistry for INSR, IGF-1R, PTEN, and AKT using optimized antibody protocols. INSR, IGF1-R, PTEN, and AKT expression between benign and cancerous tissue, and different Gleason grades was assessed. Kaplan-Meier survival curves were used to examine the relationship between proteins expression and BCR. RESULTS: INSR (P < 0.001), IGF-1R (P < 0.001), and AKT (P < 0.05) expression was significantly increased and PTEN (P < 0.001) was significantly decreased in cancerous versus benign tissue. There was no significant difference in INSR, IGF-1R, or AKT expression in the cancerous tissue of non-BCR versus BCR patients (P = 0.149, P = 0.990, P = 0.399, respectively). There was a significant decrease in PTEN expression in the malignant tissue of BCR versus non-BCR patients (P = 0.011). Combinational analysis of the tissue proteins identified a combination of decreased PTEN and increased AKT or increased INSR was associated with worst outcome. We found that in each case, our hypothesized worst group was most likely to experience BCR and this was significant for combinations of PTEN+INSR and PTEN+AKT but not PTEN+IGF-1R (P = 0.023, P = 0.028, P = 0.078, respectively). CONCLUSIONS: Low PTEN is associated with BCR and this association is strongly modified by high INSR and high AKT expression. Measurement of these proteins could help inform appropriate patient selection for postoperative adjuvant therapy and prevent BCR.