Protein kinase CK2 in health and disease: CK2: a key player in cancer biology

Elevated levels of protein kinase CK2 (formerly casein kinase 2 or II) have long been associated with increased cell growth and proliferation both in normal and cancer cells. The ability of CK2 to also act as a potent suppressor of apoptosis offers an important link to its involvement in cancer since deregulation of both cell proliferation and apoptosis are among the key features of cancer cell biology. Dysregulated CK2 may impact both of these processes in cancer cells. All cancers that have been examined show increased CK2 expression, which may also relate to prognosis. The extensive involvement of CK2 in cancer derives from its impact on diverse molecular pathways controlling cell proliferation and cell death. Downregulation of CK2 by various approaches results in induction of apoptosis in cultured cell and xenograft cancer models suggesting its potential as a therapeutic target.

The formation of an aligned 1D nanostructure on annealed Fe/ZnSe bilayers

A highly aligned one-dimensional (1D) nanostructure was realized at the surface of Fe/ZnSe bilayers grown on GaAs(001) substrates through thermal annealing. These 1D nano-grooves were found to align along the [110] direction resulting in bent reflection high energy electron diffraction (RHEED) patterns when the sample was rotated relative to the e-beam. A model based on Ewald construction is presented to explain the unusual RHEED observation. The formation mechanism of this 1D nanostructure is possibly related to the minimization of surface energy, together with an Fe-Se exchange interaction and Fe-induced decomposition of several top ZnSe atomic layers during thermal annealing.

Small molecule pan-bcl-2 inhibitor AT-101 induces apoptosis in NSCLC by up-regulating noxa and enhances antitumor activity of docetaxel or targeted kinase inhibitors

e14591

Background: AT-101 is an orally active pan Bcl-2 inhibitor currently under clinical development in Phase II trials. We investigated the effect of AT-101 alone or in combination with chemotherapies or targeted kinase inhibitors in NSCLC both in vitro and in vivo. Methods: Growth inhibition was measured by WST assays. The CalculSyn method was used to assess drug interaction by calculating the Combination Index (CI) value. The ability of AT-101 to potentiate the anti-cancer effect of chemotherapies or kinase inhibitors was evaluated in xenograft models. Results: A panel of 11 NSCLC cell lines with overexpression of Bcl-2, Bcl- XL or Mcl-1 proteins was treated with AT-101, docetaxel, pemetrexed, erlotinib, sorafenib, sunitinib, rapamycin, as a single agent and in combination. AT-101 inhibited the growth with IC50 at 3–9 uM. When treating cells simultaneously with both agents, AT-101 demonstrated strong synergy with those agents in A549 or H460 cells with CI values < 1.0. Protein analysis results indicated that AT-101 caused apoptosis by a time- and dose-dependent induction of Noxa expression in those cells. The expression of Bcl- XL was not influenced by AT-101. Pro-Caspase-3 was reduced with increasing doses of AT-101. In vivo, combined treatment of AT-101 with docetaxel, erlotinib, or sorafenib synergistically suppressed subcutaneous NSCLC A549 cells tumor growth compared with treatment with either agent alone. The synergist effects with the ErbB1 inhibitor Erlotinib is associated with the overexpression of the target protein ErbB1 in those cells. Only combination therapy resulted in significant tumor growth delay and no significant toxicities were observed. Conclusions: Our results demonstrate that AT-101significantly enhances the anti-tumor activity of chemotherapy and targeted agents and may represent a promising new anticancer agent with a novel molecular mechanism. Molecular targeted therapy with AT-101 may improve the outcome of current chemotherapy for NSCLC with Bcl-2, Bcl-xL and/or Mcl-1 overexpression.

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Skp2, a prognostic marker and potential therapeutic target in metastatic melanoma

11034

Background: Skp2, a known oncogene, is overexpressed in several types of tumors and is associated with worse recurrence rate and overall survival in primary melanoma patients. Moreover, the anti-proliferative effects of Skp2 siRNA on various tumor cell lines have prompted the preclinical testing of Skp2 small molecule inhibitors. In this study, we assessed the clinical relevance and molecular mechanism(s) underlying Skp2 overexpression in metastatic melanoma patients. Methods: Skp2 protein levels were measured in 122 metastatic melanoma specimens using immunohistochemistry (IHC), and the association between Skp2 overexpression and post-recurrence survival was examined. Moreover, 22 cell lines (2 normal primary melanocytes, 2 primary immortal melanocytes, 4 primary melanoma cell lines, and 18 metastatic melanoma cell lines) were evaluated for Skp2 genomic amplification using Single Nucleotide Polymorphism (SNP) arrays (Affymetrix 6.0) and Skp2 gene expression using mRNA arrays (Affymetrix U133A 2.0) and quantitative RT-PCR. We also screened 18 cell lines for Skp2 mutation by sequencing. Results: Skp2 overexpression, defined as >25% tumor cells, was associated with shorter 3-yr post-recurrence survival (37%) compared to Skp2 expression ≤25% (55%) (HR=1.89, 95%, CI= 1.04, 3.42, p=0.04). Skp2 overexpression was significantly associated with the site of melanoma metastasis: visceral (n= 12; 89%), lymph node (n=49; 36%), brain (n=15; 14%), and soft-tissue (n=36; 6%) (p<0.001). SNP array revealed genomic amplification at the Skp2 locus in 6 (33%) metastatic cell lines and one primary melanoma cell line. Skp2 genomic amplification was associated with increased transcript expression. No Skp2 mutations were identified. Conclusions: Skp2 protein overexpression is associated with worse prognosis in metastasis in melanoma. Our results also support that gene amplification, rather than a Skp2 gene mutation, may be the major mechanism responsible for Skp2 aberrant expression in metastatic melanoma.

No significant financial relationships to disclose.

A broadband imaging system for research applications

We have developed a compact, computer-piloted, high sensitivity broadband imaging system for laboratory research that is compatible with various detectors. Mirror optics allow application from the visible to the far infrared spectral range. A prototype tested in conjunction with a mercury cadmium telluride detector exhibits a peak detectivity of 6.7x10(10) cm Hz(1/2)/W at a wavelength of 11.8 microm. Temperature and spatial resolutions of 0.06 K and 1.6 mrad, respectively, were demonstrated.

Observation of two-source interference in the photoproduction reaction AuAu --> AuAurho0

In ultraperipheral relativistic heavy-ion collisions, a photon from the electromagnetic field of one nucleus can fluctuate to a quark-antiquark pair and scatter from the other nucleus, emerging as a rho{0}. The rho{0} production occurs in two well-separated (median impact parameters of 20 and 40 F for the cases considered here) nuclei, so the system forms a two-source interferometer. At low transverse momenta, the two amplitudes interfere destructively, suppressing rho{0} production. Since the rho{0} decays before the production amplitudes from the two sources can overlap, the two-pion system can only be described with an entangled nonlocal wave function, and is thus an example of the Einstein-Podolsky-Rosen paradox. We observe this suppression in 200 GeV per nucleon-pair gold-gold collisions. The interference is 87%+/-5%(stat.)+/-8%(syst.) of the expected level. This translates into a limit on decoherence due to wave function collapse or other factors of 23% at the 90% confidence level.

The Pirh2-keratin 8/18 interaction modulates the cellular distribution of mitochondria and UV-induced apoptosis

Intermediate filaments (IFs) provide crucial structural support in higher eukaryotic cells. Accumulating evidences show that IFs also participate in various cellular activities including stress responses, cell growth, cell death and cell migration through dynamic interactions with various non-structure proteins. Here we report the identification of Pirh2, a RING-H2-type ubiquitin E3 ligase, as a novel binding partner of the cytoplasmic IF proteins keratin 8/18 (K8/18). Phosphorylation of either Pirh2 or K8/18 affects their association. Although Pirh2 was not found to influence the stability of K8/18, it displayed an unexpected role in regulating the organization of the network of K8/18 keratin filaments. Disruption of Pirh2-K8/K18 interaction by either UV irradiation or knockdown with Pirh2 or K18 led to the aggregation of K8/18 keratin filaments. It further induced mitochondrial redistribution, and this process is likely through a microtubule-mediated pathway. The abnormal localization of mitochondria in Pirh2-knockdown cells may partially account for its increased cell sensitivity to UV-induced apoptosis, probably through enhancing the release of pro-apoptotic proteins, such as cytochrome c and Smac/DIABLO to the cytosol. Overall, our data reveal the novel role of the Pirh2-K8/18 complex in governing the distribution of mitochondria.

Rac1 signaling regulates CTGF/CCN2 gene expression via TGFbeta/Smad signaling in chondrocytes

OBJECTIVE

Connective tissue growth factor (CTGF) has been implicated in regulation of chondrocyte differentiation at multiple steps and has been implicated in the progression of diseases such as scleroderma and osteoarthritis. However, the pathways mediating the expression of CTGF/CCN2 and related factors in cartilage are not fully understood. We have previously shown that the Rho family of proteins and the actin cytoskeleton regulate both early and late chondrocyte differentiation.

RESULTS

Here we demonstrate that several CTGF/Cyr61/Nov (CCN) family members are differentially affected by either inhibition of actin polymerization (cytochalasin D treatment), promotion of actin polymerization (jasplakinolide treatment), inhibition of RhoA/rho kinase (ROCK) signaling (Y27632 treatment) and Rac1 signaling. We also show that the Smad site in the CTGF/CCN2 promoter is responsive to both Rac1 inhibition and cytochalasin D treatment, suggesting a role of TGFbeta/Smad signaling in mediating the effects of actin dynamics and Rac1.

CONCLUSION

Collectively, these data show that Rac1 and actin pathways control CTGF/CCN2 expression in chondrocytes which might be relevant to both skeletal development and associated diseases such as osteoarthritis.

Indications of conical emission of charged hadrons at the BNL relativistic heavy ion collider

Three-particle azimuthal correlation measurements with a high transverse momentum trigger particle are reported for pp, d+Au, and Au+Au collisions at sqrt[s_{NN}]=200 GeV by the STAR experiment. Dijet structures are observed in pp, d+Au and peripheral Au+Au collisions. An additional structure is observed in central Au+Au data, signaling conical emission of correlated charged hadrons. The conical emission angle is found to be theta=1.37+/-0.02(stat)-0.07+0.06(syst), independent of p_{ perpendicular}.

Identification of genes that confer tumor cell resistance to the aurora B kinase inhibitor, AZD1152

AZD1152 is a highly selective Aurora B kinase inhibitor currently undergoing Phase I and II clinical evaluation in patients with acute myelogenous leukemia and advanced solid malignancies. We have established two AZD1152-resistant cell lines from SW620 colon and MiaPaCa pancreatic carcinoma lines, which are >100-fold resistant to the active metabolite of AZD1152, AZD1152 HQPA and interestingly, cross-resistant to the pan-Aurora kinase inhibitor, VX-680/MK0457. Using whole-genome microarray analysis and comparative genomic hybridization, we were able to identify MDR1 and BCRP as the causative genes that underlie AZD1152 HQPA-resistance in these models. Furthermore, the upregulation of either of these genes is sufficient to render in vivo tumor growth insensitive to AZD1152. Finally, the upregulation of MDR1 or BCRP is predictive of tumor cell sensitivity to this agent, both in vitro and in vivo. The data provide a genetic basis for resistance to Aurora kinase inhibitors, which could be utilized to predict clinical response to therapy.

Application of cumulative odds logistic model on risk factors analysis for sexually transmitted infections among female sex workers in Kaiyuan city, Yunnan province, China

OBJECTIVES

To investigate the epidemiology of sexually transmitted infections (STI) among female sex workers (FSW) in Kaiyuan city, Yunnan province, China, and to identify risk factors associated with STI.

METHODS

A cross-sectional study of 737 FSW was carried out from March to May 2006, with confidential interviews and laboratory tests for STI. A cumulative logit model was used to evaluate the risk factors for STI.

RESULTS

The overall prevalence of HIV is 10.3%. The prevalence of syphilis, herpes simplex virus type 2, gonorrhoea, chlamydia and trichomonas was 7.5%, 68.1%, 8.3%, 25.9% and 10.6%, respectively. In multivariate cumulative odds logistic analysis, the factors associated with STI were education level, living in the entertainment location, injection drug use, non-injection drug use, over five clients in the previous week and inconsistent use of condoms with clients.

CONCLUSION

The findings highlight the gravity of the STI epidemic among FSW in China, where sexual transmission has now overtaken unsafe injection practices as the dominant mode of HIV transmission. Targeted intervention programmes for FSW should focus on increasing condom use, strengthening knowledge and awareness of STI/HIV and encouraging routine screening and treatment-seeking behaviours. Reducing the spread of STI also has profound implications for the prevention of HIV.

Awareness of breast cancer among women in an urban region of China

Abstract #2104

Introduction: Even though breast cancer can be cured if detected early and treated appropriately, it remains the most common cause of cancer mortality for women living in some major cities in China. Moreover, the incidence of this disease has increased steadily in China over the last two decades. The aim of this cross-sectional study was to investigate the knowledge about breast cancer concerning risk factors, signs and symptoms, effective screening methods, treatment choices and prognosis among native Chinese women.&#x2028; Method: Two hundred and seventy healthy women were invited to complete a self-administered questionnaire in Taiyuan city of China. Participants' characteristics, including age, education, occupation, and awareness of breast cancer diagnosis, treatment and prognosis were collected and analyzed.&#x2028; Results: Two hundred and thirty nine women had returned the questionnaire. The response rate was 88.5%. The median age of women in this study was 44 years old (range: 25 – 72). Among them, more than one third had received tertiary education, 6.7% had breast cancer family history, and one quarter ever had benign breast disease. Most of the participants (60.3%) did not know how to perform breast self-examination (BSE), whereas 61.5% never did BSE. Only 2.9% of those who had performed BSE did so regularly. As for effective screening methods, more than half of the participants chose clinical breast examination (CBE), and 21.8% regarded mammography as a reliable mean. Most of women considered breast cancer a curable disease and assumed that therapeutic approaches should include surgery, chemotherapy, endocrine therapy, radiotherapy, and in some cases, traditional Chinese medicine. Only 8.8% of the participants identified two or more of the eight breast cancer risk factors. The factors mostly identified included breast cancer family history (33.5%), late birth (10%), and early age at menarche (9.6%). The breast cancer signs and symptoms mostly indicated were breast lump (54.4%), breast pain (26.4%), and nipple discharge (23.9%). Women who received high level education appeared to be more likely to perform BSE and possessed more knowledge regarding to breast cancer risk factors and treatment.&#x2028; Conclusion: The study indicates that awareness of breast cancer among Chinese women needs to be improved, and that breast cancer early-detection measures needs to be enhanced in China.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2104.

Search for weakly interacting massive particles with the first five-tower data from the cryogenic dark matter search at the soudan underground laboratory

We report results from the Cryogenic Dark Matter Search at the Soudan Underground Laboratory (CDMS II) featuring the full complement of 30 detectors. A blind analysis of data taken between October 2006 and July 2007 sets an upper limit on the weakly interacting massive particle (WIMP) nucleon spin-independent cross section of 6.6x10;{-44} cm;{2} (4.6x10;{-44} cm;{2} when combined with previous CDMS II data) at the 90% confidence level for a WIMP mass of 60 GeV/c;{2}. This achieves the best sensitivity for dark matter WIMPs with masses above 44 GeV/c;{2}, and significantly restricts the parameter space for some favored supersymmetric models.