CIP2A regulates MYC translation (via its 5'UTR) in colorectal cancer.

BACKGROUND: Deregulated expression of MYC is a driver of colorectal carcinogenesis, suggesting that decreasing MYC expression may have significant therapeutic value. CIP2A is an oncogenic factor that regulates MYC expression. CIP2A is overexpressed in colorectal cancer (CRC), and its expression levels are an independent marker for long-term outcome of CRC. Previous studies suggested that CIP2A controls MYC protein expression on a post-transcriptional level. METHODS: To determine the mechanism by which CIP2A regulates MYC in CRC, we dissected MYC translation and stability dependent on CIP2A in CRC cell lines. RESULTS: Knockdown of CIP2A reduced MYC protein levels without influencing MYC stability in CRC cell lines. Interfering with proteasomal degradation of MYC by usage of FBXW7-deficient cells or treatment with the proteasome inhibitor MG132 did not rescue the effect of CIP2A depletion on MYC protein levels. Whereas CIP2A knockdown had marginal influence on global protein synthesis, we could demonstrate that, by using different reporter constructs and cells expressing MYC mRNA with or without flanking UTR, CIP2A regulates MYC translation. This interaction is mainly conducted by the MYC 5'UTR. CONCLUSIONS: Thus, instead of targeting MYC protein stability as reported for other tissue types before, CIP2A specifically regulates MYC mRNA translation in CRC but has only slight effects on global mRNA translation. In conclusion, we propose as novel mechanism that CIP2A regulates MYC on a translational level rather than affecting MYC protein stability in CRC.

Stabilization of nuclear oncoproteins by RNF4 and the ubiquitin system in cancer.

RNF4, a SUMO-targeted ubiquitin ligase, stabilizes a selected group of oncoproteins. It potentiates oncoprotein activity and serves as a positive feedback agonist of Wnt and Notch pathways. RNF4 is essential for cancer cell survival and its levels are elevated in human cancers, correlating with poor outcome in a subset of cancer patients.

[Experimental treatment of malignant melanoma and its rationale]. / Experimentelle Tumortherapie beim malignen Melanom und ihre Rationale.

To treat malignant melanoma successfully currently means to recognize the tumor at an early stage and to remove it immediately. Aside from individual cases, available treatment modalities are not able to increase survival, especially in the palliative situation. Thus innovative experimental approaches are urgently needed to strongly improve the palliative and adjuvant treatment of melanoma. Anti-tumor effects are expected from targeted therapies, which are directed against defined molecules decisive for tumor pathogenesis. Crucial points of attack are signaling pathways, angiogenesis and apoptosis resistance. New diagnostic and therapeutic developments have enhanced the efficacy of chemotherapies. Increasing insights into tumor immunology provide new treatment approaches of vaccination, cell transfer and especially of blocking immune tolerance mechanisms. It will be challenging for the future to identify and characterize more precisely those patients who might most benefit from a certain treatment approach.

Acupuncture compared to placebo-acupuncture for postoperative nausea and vomiting prophylaxis: a randomised placebo-controlled patient and observer blind trial.

This randomised, placebo-controlled, patient and observer blinded trial was conducted to determine whether acupuncture at the acupuncture point P6 is effective in preventing postoperative nausea and vomiting (PONV) compared to placebo acupuncture. Female patients (n = 220) scheduled for gynaecological or breast surgery were randomly assigned to two groups receiving either acupuncture (n = 109) or placebo acupuncture (n = 111). Each group was stratified for type of surgery and included two subgroups receiving intervention either before or after induction of anaesthesia. The incidence of PONV and/or antiemetic rescue medication within 24 h after surgery was the main outcome measure which showed no statistically significant difference between groups (43.7% acupuncture, 50.9% placebo, p = 0.27). The differences were more pronounced for patients having gynaecological surgery (48.9% acupuncture, 67.6% placebo, p = 0.07) than for those having breast surgery (38.7% acupuncture, 40.3% placebo, p = 0.86). The secondary outcome, vomiting, was significantly reduced by acupuncture from 39.6% to 24.8% (p = 0.03). Subgroup analysis showed no difference between applications of acupuncture before compared to after induction of anaesthesia.