Phosphoproteome and drug-response effects mediated by the three protein phosphatase 2A inhibitor proteins CIP2A, SET, and PME-1

Protein phosphatase 2A (PP2A) critically regulates cell signaling and is a human tumor suppressor. PP2A complexes are modulated by proteins such as cancerous inhibitor of protein phosphatase 2A (CIP2A), protein phosphatase methylesterase 1 (PME-1), and SET nuclear proto-oncogene (SET) that often are deregulated in cancers. However, how they impact cellular phosphorylation and how redundant they are in cellular regulation is poorly understood. Here, we conducted a systematic phosphoproteomics screen for phosphotargets modulated by siRNA-mediated depletion of CIP2A, PME-1, and SET (to reactivate PP2A) or the scaffolding A-subunit of PP2A (PPP2R1A) (to inhibit PP2A) in HeLa cells. We identified PP2A-modulated targets in diverse cellular pathways, including kinase signaling, cytoskeleton, RNA splicing, DNA repair, and nuclear lamina. The results indicate nonredundancy among CIP2A, PME-1, and SET in phosphotarget regulation. Notably, PP2A inhibition or reactivation affected largely distinct phosphopeptides, introducing a concept of nonoverlapping phosphatase inhibition- and activation-responsive sites (PIRS and PARS, respectively). This phenomenon is explained by the PPP2R1A inhibition impacting primarily dephosphorylated threonines, whereas PP2A reactivation results in dephosphorylation of clustered and acidophilic sites. Using comprehensive drug-sensitivity screening in PP2A-modulated cells to evaluate the functional impact of PP2A across diverse cellular pathways targeted by these drugs, we found that consistent with global phosphoproteome effects, PP2A modulations broadly affect responses to more than 200 drugs inhibiting a broad spectrum of cancer-relevant targets. These findings advance our understanding of the phosphoproteins, pharmacological responses, and cellular processes regulated by PP2A modulation and may enable the development of combination therapies

Gene Organization in Rice Revealed by Full-Length cDNA Mapping and Gene Expression Analysis through Microarray

Rice (Oryza sativa L.) is a model organism for the functional genomics of monocotyledonous plants since the genome size is considerably smaller than those of other monocotyledonous plants. Although highly accurate genome sequences of indica and japonica rice are available, additional resources such as full-length complementary DNA (FL-cDNA) sequences are also indispensable for comprehensive analyses of gene structure and function. We cross-referenced 28.5K individual loci in the rice genome defined by mapping of 578K FL-cDNA clones with the 56K loci predicted in the TIGR genome assembly. Based on the annotation status and the presence of corresponding cDNA clones, genes were classified into 23K annotated expressed (AE) genes, 33K annotated non-expressed (ANE) genes, and 5.5K non-annotated expressed (NAE) genes. We developed a 60mer oligo-array for analysis of gene expression from each locus. Analysis of gene structures and expression levels revealed that the general features of gene structure and expression of NAE and ANE genes were considerably different from those of AE genes. The results also suggested that the cloning efficiency of rice FL-cDNA is associated with the transcription activity of the corresponding genetic locus, although other factors may also have an effect. Comparison of the coverage of FL-cDNA among gene families suggested that FL-cDNA from genes encoding rice- or eukaryote-specific domains, and those involved in regulatory functions were difficult to produce in bacterial cells. Collectively, these results indicate that rice genes can be divided into distinct groups based on transcription activity and gene structure, and that the coverage bias of FL-cDNA clones exists due to the incompatibility of certain eukaryotic genes in bacteria

Extracorporeal Irradiation and Reimplantation with Total Hip Arthroplasty for Periacetabular Pelvic Resections: A Review of 9 Cases.

We report the early results of nine patients with periacetabular malignancies treated with Enneking and Dunham type 2 resection and reconstruction using extracorporeally irradiated (ECI) tumour bone combined with total hip arthroplasty (THA). Diagnosis was chondrosarcoma in six patients, osteosarcoma in two patients, and metastatic renal cell carcinoma in one patient. All patients underwent surgical resection and the resected specimen was irradiated with 50 Gy in a single fraction before being prepared for reimplantation as a composite autograft. The mean follow-up was 21 months (range, 3-59). All patients were alive at latest follow-up. No local recurrence was observed. One patient serially developed three pulmonary metastases, all of which were resected. One experienced hip dislocation due to incorrect seating of an acetabular liner. This was successfully treated with revision of the liner with no further episodes of instability. There were no cases of deep infection or loss of graft. The average Musculoskeletal Tumor Society (MSTS) score was 75% (range, 57-87%). Type 2 pelvic reconstruction with ECI and THA has shown excellent early oncological and functional results in our series. Preservation of the gluteus maximus and hip abductors is important for joint stability and prevention of infection

Clinical Features of High-Grade Extremity and Trunk Sarcomas in Patients Aged 80 Years and Older: Why Are Outcomes Inferior?

Background: The population of many countries is aging and a significant number of elderly patients with soft-tissue sarcoma are being seen at cancer centers. The unique therapeutic and prognostic implications of treating soft-tissue sarcoma in geriatric patients warrant further consideration in order to optimize outcomes. Patients and Methods: This is a single-institution retrospective study of consecutive non-metastatic primary extremity and trunk high-grade sarcomas surgically treated between 1996 and 2012, with at least 2 years of follow-up for survivors. Patient characteristics and oncological outcomes were compared between age groups (≥80 vs. <80 years), using Chi-square or Fisher-exact test and Log-Rank or Wilcoxon test, respectively. Deaths from other causes were censored for disease-specific survival estimation. A p< 0.05 was regarded as statistically significant. Results: A total of 333 cases were eligible for this study. Thirty-six patients (11%) were aged ≥80 years. Unplanned surgery incidence and surgical margin status were comparable between the age groups. Five-year local-recurrence-free, metastasis-free and disease-specific survivals were 72% (≥80 years) vs. 90% (<80 years) (p = 0.004), 59 vs. 70% (p = 0.07) and 55 vs. 80% (p < 0.001), respectively. A significantly earlier first metastasis after surgery (8.3 months vs. 20.5 months, mean) and poorer survival after first metastasis (p = 0.03) were observed. Cox analysis revealed "age ≥80 years" as an independent risk factor for local failure and disease-specific mortality, with hazard ratios of 2.41 (95% CI: 1.09-5.32) and 2.52 (1.33-4.13), respectively. A competing risks analysis also showed that "age ≥80 years" was significantly associated with the disease-specific mortality. Conclusions: Oncological outcomes were significantly worse in high-grade sarcoma patients aged ≥80 years. The findings of more frequent local failure regardless of a consistent primary treatment strategy, an earlier time to first metastasis after surgery, and poorer prognosis after first metastasis suggest that more aggressive tumor biology, in addition to multiple co-morbidity, may explain the inferiority

PKCζ regulates Notch receptor routing and activity in a Notch signaling-dependent manner

\u3cp\u3eActivation of Notch signaling requires intracellular routing of the receptor, but the mechanisms controlling the distinct steps in the routing process is poorly understood. We identify PKCζ as a key regulator of Notch receptor intracellular routing. When PKCζ was inhibited in the developing chick central nervous system and in cultured myoblasts, Notch-stimulated cells were allowed to undergo differentiation. PKCζ phosphorylates membrane-tethered forms of Notch and regulates two distinct routing steps, depending on the Notch activation state. When Notch is activated, PKCζ promotes re-localization of Notch from late endosomes to the nucleus and enhances production of the Notch intracellular domain, which leads to increased Notch activity. In the non-activated state, PKCζ instead facilitates Notch receptor internalization, accompanied with increased ubiquitylation and interaction with the endosomal sorting protein Hrs. Collectively, these data identify PKCζ as a key regulator of Notch trafficking and demonstrate that distinct steps in intracellular routing are differentially modulated depending on Notch signaling status.\u3c/p\u3

Phosphorylation of Notch1 by Pim kinases promotes oncogenic signaling in breast and prostate cancer cells

\u3cp\u3eTumorigenesis is a multistep process involving co-operation between several deregulated oncoproteins. In this study, we unravel previously unrecognized interactions and crosstalk between Pim kinases and the Notch signaling pathway, with implications for both breast and prostate cancer. We identify Notch1 and Notch3, but not Notch2, as novel Pim substrates and demonstrate that for Notch1, the serine residue 2152 is phosphorylated by all three Pim family kinases. This target site is located in the second nuclear localization sequence (NLS) of the Notch1 intracellular domain (N1ICD), and is shown to be important for both nuclear localization and transcriptional activity of N1ICD. Phosphorylation-dependent stimulation of Notch1 signaling promotes migration of prostate cancer cells, balances glucose metabolism in breast cancer cells, and supports in vivo growth of both types of cancer cells on chick embryo chorioallantoic membranes. Furthermore, Pim-induced growth of orthotopic prostate xenografts in mice is associated with enhanced nuclear Notch1 activity. Finally, simultaneous inhibition of Pim and Notch abrogates the cellular responses more efficiently than individual treatments, opening up new vistas for combinatorial cancer therapy.\u3c/p\u3