RITA

RITA, a p53 inducer, attenuated Cr(VI)-induced HIF-1α and LC3-II in A549 cells, suggesting that p53 might be the mechanism underlying the different effects of Cr(VI) on HIF-1α in A549 and HELF cells. Thus, p53-dependent HIF-1α / autophagy-mediated glycolysis plays a role in facilitating Cr(VI)-induced carcinogenesis.

We also found that while wt-p53 expression contributes to 5-FU sensitivity in colon cancer cells, the RITA p53 reactivating molecule counteracted the resistance against 5-FU in cells expressing mut-p53. Our results indicate that mut-p53 GOF acts as a positive regulator of canonical Wnt signaling and participates in the induction of resistance to 5-FU in colon cancer cells.

Simultaneously, inverse changes occurred at Serine S4 of the NPM. These new findings of RITA mechanism of action could establish the NPM pT199/pS4 ratio as a marker for suitability of RITA treatment of AML cells.

Loss of BAP1 results in the sensitivity of cutaneous melanoma cells to p53 activator RITA. In melanoma cells, the activity of ubiquitinase in BAP1 is directly related to their sensitivity to RITA. An increased expression of p53 protein induced by BAP1 knockout is probably a key reason for RITA sensitivity of melanoma cells, suggesting the potential of RITA as a targeted therapeutic agent for cutaneous melanoma carrying BAP1-inactivating mutations.

This discovery revealed the specific mechanism of ferroptosis induced by apatinib combined with olaparib in p53 wild-type ovarian cancer cells and provided a theoretical basis for the clinical combined use of apatinib and olaparib in p53 wild-type ovarian cancer patients.

The inhibitory effect of RITA on human OSCC cell proliferation is mediated by apoptosis induction through p53 and Bax.

First, compounds targeting degradation or direct inhibition of WT p53, such as PM2, RITA, nutlin-3 and CH1iB, achieve p53 reactivation by affecting p53 inhibitors such as MDM2 and MDMX/4 or by preventing the breakdown of p53 by inhibiting the proteasomal complex. Second, compounds that directly affect mutated p53 by binding it and restoring the WT conformation and transcriptional activity (PRIMA-1, APR-246, COTI-2, CP-31398). Third, treatments that specifically affect HPV cancer cells by targeting the viral enzymes E6/E7 which are responsible for the breakdown of p53 such as Ad-E6/E7-As and bortezomib. In this review, we describe and discuss p53 regulation and its targeting in combination with existing therapies for HNSCC through a new classification of such cancers based on p53 mutation status and HPV infection.

RITA can inhibit the proliferation and induce the apoptosis of Mino cells significantly. The mechanism may be dependent on the Caspase pathway, but independent on the P53 pathway.

Comparison of different inhibitors of WIP1 showed that SL-176 was the most potent compound inhibiting medulloblastoma and neuroblastoma growth and had similar or more potent effects on cell survival than the MDM2 inhibitor Nutlin-3 or the p53 activator RITA. SL-176 monotherapy significantly suppressed the growth of established medulloblastoma and neuroblastoma xenografts in nude mice. These results suggest that the development of clinically applicable compounds inhibiting the activity of WIP1 is of importance since PPM1D activating mutations, genetic gain or amplifications and/or overexpression of WIP1 are frequently detected in several different cancers.

Andrographolide inhibited the colony formation abilities in SGC7901 in a p53-dependent manner followed by induction of mitochondrial intrinsic apoptosis through activation of caspases-9 and -3, cleavage of PARP, and inhibition of pro-apoptotic Bcl-2. Andrographolide induced p53 mediated apoptosis in gastric carcinoma cells which adds to a novel approach in anticancer therapies.

No abstract available