Compositions and methods relating to induction of intestinal stem cell homeogenesis and/or regeneration

1. A method for treating and/or preventing intestinal tissue damage resulting from exposure to an intestinal stem cell damaging event, comprising administering to a subject in need thereof a composition comprising a R-spondin 1 (Rspo1) agent and a Slit guidance ligand 2 (Slit2) agent, wherein said Rspo1 agent is a human Rspo1 protein, wherein said Slit2 agent is a human Slit2 protein,

wherein said intestinal tissue comprises Roundabout 1 (Robo1) expression,

wherein said Rspo1 agent is capable of binding the location on Robo1 where endogenous Rspo1 binds Robo1,

wherein said Slit2 agent is capable of binding the location on Robo1 where endogenous Slit2 binds Robo1,

wherein said administering of said composition comprising a Rspo1 agent and a Slit2 agent results in binding of said Rspo1 agent with Robo1 and binding of said Slit2 agent with Robo1 within said intestinal tissue,

wherein said administering of said composition results in induction of intestinal stem cell homeogenesis and/or regeneration,

wherein said subject is a human,

wherein said intestinal stem cell damaging event is radiation therapy and/or chemotherapy, and

wherein said composition comprising a Rspo1 agent and a Slit2 agent is administered prior to, concurrently with, and/or after exposure to the intestinal stem cell damaging event.

2. The method of claim 1 , wherein said human has cancer and is undergoing radiation treatment.

3. The method of claim 1 ,

wherein said binding of said Rspo1 agent with Robo1 and said binding of said Slit2 agent with Robo1 results in binding of Robo1 with lipoprotein receptor-related protein 6 (LRP6),

wherein said binding of Robo1 with LRP6 occurs at the CC3 motif within Robo1, and

wherein said binding of Robo1 with LRP6 results in phosphorylation of said LRP6.

4. The method of claim 3 , wherein said binding of said Rspo1 agent with Robo1 and said binding of said Slit2 agent with Robo1 results in at least one of the following:

association of Robo1 with leucine-rich repeat-containing G-protein coupled receptor 5 (LRG5),

β-catenin translocation, and

Wnt/β-catenin activation within said intestinal tissue, wherein said Wnt/β-catenin activation within said intestinal tissue transcriptionally represses p53 expression and inhibits p53-mediated intestinal stem cell (ISC) apoptosis.

5. The method of claim 1 , wherein said intestinal tissue is small intestinal tissue.

6. The method of claim 1 , wherein said intestinal tissue is the crypt region of a small intestine.

7. The method of claim 1 , wherein said intestinal stem cell damaging event is an exposure to a medical procedure involving radiation.

8. The method of claim 7 , wherein the medical procedure involving radiation is selected from the group consisting of photon radiotherapy, particle beam radiation therapy, brachytherapy, interstitial irradiation, intracavity irradiation, radioimmunotherapy, and ionizing (electromagnetic) radiotherapy.

9. A method for treating a human subject having a disorder, comprising administering to said subject a medical procedure involving radiation, and further administering during the course of said medical procedure a composition comprising a R-spondin 1 (Rspo1) agent and a Slit guidance ligand 2 (Slit2) agent, wherein said Rspo1 agent is a human Rspo1 protein, wherein said Slit2 agent is a human Slit2 protein,

wherein said intestinal tissue comprises Roundabout 1 (Robo1) expression,

wherein said Rspo1 agent is capable of binding the location on Robo1 where endogenous Rspo1 binds Robo1,

wherein said Slit2 agent is capable of binding the location on Robo1 where endogenous Slit2 binds Robo1,

wherein said administering of said composition comprising a Rspo1 agent and a Slit2 agent results in binding of said Rspo1 agent with Robo1 and binding of said Slit2 agent with Robo1 within said intestinal tissue,

wherein said binding of said Rspo1 agent with Robo1 and said binding of said Slit2 agent with Robo1 results in binding of Robo1 with lipoprotein receptor-related protein 6 (LRP6), wherein said binding of Robo1 with LRP6 occurs at the CC3 motif within Robo1, wherein said binding of Robo1 with LRP6 results in phosphorylation of said LRP6,

wherein said administration of said composition treats and/or prevents intestinal tissue damage resulting from said medical procedure,

wherein said administering of said composition results in induction of intestinal stem cell homeogenesis and/or regeneration,

wherein said disorder is cancer,

wherein said medical procedure involving radiation is selected from the group consisting of photon radiotherapy, particle beam radiation therapy, brachytherapy, interstitial irradiation, intracavity irradiation, radioimmunotherapy, and ionizing (electromagnetic) radiotherapy, and

wherein said composition comprising a Rspo1 agent and a Slit2 agent is administered prior to, concurrently with, and/or after administration of said medical procedure involving radiation.

10. The method of claim 9 , wherein said binding of said Rspo1 agent with Robo1 and said binding of said Slit2 agent with Robo1 results in one or more of the following:

association of Robo1 with leucine-rich repeat-containing G-protein coupled receptor 5 (LRG5),

β-catenin translocation, and

Wnt/β-catenin activation within said intestinal tissue, wherein said Wnt/β-catenin activation within said intestinal tissue transcriptionally represses p53 expression and inhibits p53-mediated intestinal stem cell (ISC) apoptosis.

11. The method of claim 9 , wherein said intestinal tissue is small intestinal tissue.

12. The method of claim 9 , wherein said intestinal tissue is the crypt region of a small intestine.