A short-term chick embryo in vivo xenograft model to study retinoblastoma cancer stem cells

Purpose: Cancer stem cells (CSCs) reported in various tumors play a crucial role in tumorigenesis and metastasis of retinoblastoma (Rb). Following the efforts to reduce, replace, and refine the use of mammalian models, we aimed to establish a short?term xenograft for Rb to evaluate the CSC properties of CD133? Rb Y79 cells, using the well?established chick embryo chorioallantoic membrane (CE?CAM) assay. Methods: Y79 cells were cultured, labeled with two different dyes (CM?Dil Y79 and enhanced green fluorescent protein (eGFP)) and sorted for CD133? and CD133 + subsets. Two million cells from each of the labeled groups were transplanted onto the abraded CAM on embryonic day 7 (E7). On E14, the tumor nodule formation on CAM and spontaneous metastasis to the embryos were evaluated by confocal microscopy, in vivo imaging, and histology. Results: Y79 cells formed pink–white raised perivascular nodules with feeder vessels on the CAM with both the types of labeled CD133? cells. CD133? cells, when compared to CD133 + cells, demonstrated significantly larger tumor volume (40.45 ± 7.744 mm3 vs 3.478 ± 0.69 mm3, P = 0.0014) and higher fluorescence intensity (CM?Dil: AUF = 6.37 × 107 ± 7.7 × 106 vs 1.08 × 107 ± 1.6 × 106; P < 0.0001; eGFP: AUF = 13.94 × 104 ± 2.54 × 104 vs AUF = 1.39 × 104 ± 0.4 × 104; P = 0.0003). The metastatic potential of CD133? cells was also observed to be higher as noted by in vivo imaging and histopathology. Conclusion: This study highlights that CE?CAM is a feasible alternative nonmammalian model for evaluating tumorigenicity and metastatic potential of Y79 CSCs. Increased tumorigenicity and metastatic potential of CD133? subset of tumor cells substantiate their CSC properties

Combination therapy of low-fluence photodynamic therapy and intravitreal ranibizumab for choroidal neovascular membrane in choroidal osteoma.

Choroidal osteoma is an unusual form of intraocular calcification seen in otherwise healthy eyes. It is a benign idiopathic osseous tumor of the choroid, typically seen in young females. Choroidal neovascular membrane (CNVM) is a complication seen in one-third of these patients and carries a poor visual outcome. We report a case of a 25-year-old hyperthyroid female with choroidal osteoma and subfoveal CNVM in her left eye which was successfully treated using low-fluence photodynamic therapy (PDT) with verteporfin followed by a single injection of intravitreal ranibizumab.

Combination treatment of low fluence photodynamic therapy and intravitreal ranibizumab for choroidal neovascular membrane secondary to angioid streaks in Paget's disease – 12 month results.

Angioid streaks also called Knapp striae are small breaks in the Bruch's membrane and have been reported with a host of systemic diseases. Rupture of streaks or development of secondary choroidal neovascular membrane (CNVM) carries a dismal visual prognosis. We report the successful treatment of CNVM secondary to Paget's disease using low fluence photodynamic therapy (PDT) and intravitreal ranibizumab.