Organization for rare diseases India (ORDI) - addressing the challenges and opportunities for the Indian rare diseases' community.

In order to address the unmet needs and create opportunities that benefit patients with rare disease in India, a group of volunteers created a not-for-profit organization named Organization for Rare Diseases India (ORDI; www.ordindia.org).

Induction of p16ink4a and p19ARF by TGFbeta1 contributes to growth arrest and senescence response in mouse keratinocytes.

TGFbeta1 acts as a potent negative regulator of the cell cycle and tumor suppressor in part through induction of cyclin dependent kinase inhibitors p15(ink4b), p21, and p57. We previously showed that primary mouse epidermal keratinocytes (MEK) expressing a v-ras(Ha) oncogene undergo hyperproliferation followed by growth arrest and senescence that was dependent on TGFbeta1 signaling and associated with increased levels of p16(ink4a) and p19(ARF). Here we show that the induction of both p16(ink4a) and p19(ARF) in v-ras(Ha) expressing keratinocytes is dependent on TGFbeta1 signaling, as TGFbeta1 treatment or Smad3 overexpression induces both p16(ink4a) and p19(ARF) protein and mRNA, while Smad3 depletion or Smad7 overexpression blocks induction.

Strain-dependent differences in malignant conversion of mouse skin tumors is an inherent property of the epidermal keratinocyte.

The multistage evolution of squamous skin tumors induced by chemical or viral carcinogens on mice from different genetic backgrounds has been a valuable model to define low penetrance loci that determine cancer susceptibility or resistance. Susceptibility determinants are multigenic, stage-specific, dependent on the carcinogenesis protocol, and in the case of initiating events, intrinsic properties of keratinocytes. In this study we examined the malignant conversion frequency of keratinocytes derived from FVB/N, inbred SENCARA/Pt, BALB/c or C57BL/6 mouse strains that differ substantially in the frequency of progression from papilloma to carcinoma.

Smad3 regulates senescence and malignant conversion in a mouse multistage skin carcinogenesis model.

Transforming growth factor beta (TGF-beta) is a growth-inhibitory cytokine for epithelial cells. In the mouse multistage skin carcinogenesis model, defects in TGF-beta 1 signaling reduce senescence in vitro and accelerate malignant progression in vivo. However, the precise postreceptor signaling pathways and specific roles played by Smad proteins in this process have not been defined.