Methods, Agents, and Compound Screening Assays for Inducing Differentiation of Undifferentiated Mammalian Cells into Osteoblasts

An agent for inducing the differentiation of undifferentiated mammalian cells into osteoblasts, selected from the group consisting of an antisense polynucleotide, a ribozyme, and a small interfering RNA (siRNA), wherein said agent comprises a nucleic acid sequence complementary to, or engineered from, a naturally-occurring polynucleotide sequence encoding a polypeptide comprising an amino acid sequence selected from the group consisting of SEQ ID NO:

• 194-309.

A method for in vitro production of bone tissue, comprising the steps of contacting undifferentiated mammalian cells with a polynucleotide sequence comprising a sequence selected from the group consisting of SEQ ID No:

• 1-77 for a time sufficient to differentiate the undifferentiated cells into osteoblasts, thereby producing a continuous bone matrix.

A method for diagnosing a pathological condition involving a systemic or local decrease in mean bone density or a susceptibility to the condition in a subject, comprising determining the amount of polypeptide comprising an amino acid sequence selected from the group consisting of SEQ ID NO:

• 194-309 in a biological sample, and comparing the amount with the amount of the polypeptide in a healthy subject, wherein an increase of the amount of polypeptide compared to the healthy subject is indicative of the presence of the pathological condition.