Treatment of angiogenesis disorders

1. A method for quantifying a RNA-encoding nucleic acid, comprising,

introducing a polynucleotide encoding an exogenous shRNA, RNAi, microRNA, or non-coding RNA molecule into a population of starting cancer cells to generate a population of engineered cancer cells;

transplanting a first portion of said population of engineered cancer cells into a tissue of the body of an animal;

maintaining the animal for a period of time to allow the transplanted engineered cancer cells to form a tumor;

assessing the quantity of a nucleic acid encoding the exogenous shRNA, RNAi, microRNA, or non-coding RNA molecule in the tumor, and

comparing said quantity to a reference quantity, wherein the reference quantity is obtained in the same manner from a second portion of said population of engineered cancer cells except that said second portion has not be transplanted to any tissue.

2. The method of claim 1 , wherein the population of starting cancer cells is obtained according to a method for generating a population of mammalian cancer cells with increased metastatic tissue colonization potential, comprising performing serial rounds of transplantation, isolation, and repeat transplantation of a population of labeled or unlabeled cancer cells into a living tissue.

3. The method of claim 1 , wherein the assessing step is performed using microarray analysis, DNA sequencing technology, deep sequencing technology, or cloning analysis.

4. The method of claim 1 , wherein the exogenous shRNA, RNAi, microRNA, or non-coding RNA molecule is overexpressed in the engineered cancer cells.

5. The method of claim 1 , wherein the introducing step comprises introducing a retrovirus having said polynucleotide into said population of starting cancer cells.

6. The method of claim 1 , wherein a decrease in said quantity relative to said reference quantity indicates that a target gene of the exogenous shRNA, RNAi, microRNA, or non-coding RNA molecule represents a gene required for metastatic colonization of said tissue.

7. The method of claim 1 , wherein the nucleic acid is genomic DNA.

8. The method of claim 5 , wherein the nucleic acid is genomic DNA.

9. The method of claim 8 , wherein the genomic DNA is derived from the retrovirus.

10. The method of claim 1 , wherein the starting cancer cells have increased metastatic tissue colonization potential.

11. The method of claim 10 , wherein the starting cancer cells are generated by a process comprising performing serial rounds of transplantation, isolation, and repeat transplantation of a population of labeled or unlabeled cancer cells into a living tissue.