Function of HES6 an Inhibitor of HES1, in the Breast Cancer Cell Lines T47D and MCF-7 Is to Up-Regulate E2F-1 and Increased Proliferation

Hormone resistance remains as a major obstacle in breast cancer treatment. The majority of breast tumors are dependent on estrogens to grow, therefore anti-estrogens such as Tamoxifen is an effective treatment option. We have found that a transcription factor Hes6, earlier described in the nervous tissue, is up-regulated in hormone-independent breast cancer cells compared to normal estrogen sensitive breast cancer cells. By using a lenti-virus system, we have over-expressed Hes6 in T47D cells which are estrogen sensitive. This resulted in increased proliferation. We also found that estrogen treatment of MCF-7 breast cancer cells induced expression of endogenous Hes6 in the G1-phase. We could not find any binding of estrogen receptor α to the HES6 gene but instead found a binding site up-steam of the promoter in the ASCL1 gene. ASCL1 is a known inducer of HES6 and we are showing that ASCL1 is up-regulated by 17β-estradiol in MCF-7 cells. To find the mechanism behind the tumorogenic effects of Hes6, we analysed important factors of the cell-cycle. We found that the G1-phase factor E2F-1 was up-regulated in response to increased Hes6 expression. Since HES6 have been shown to be an inhibitor of HES1, this is in agreement with a previous study where we found that HES1 inhibited proliferation by binding to the promoter of and down-regulating E2F-1 expression. E2F-1 is an important limiting factor in late G1-phase of the cell cycle and can drive cell proliferation.We believe that the HES1-HES6 interplay is important in antiestrogen-resistant breast cancer. Studies are now ongoing to investigate if Hes6 is up-regulated in estrogen-independent human breast cancer samples.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2153.

Chromate reduction by zero-valent Al metal as catalyzed by polyoxometalate

In spite of a high reduction potential of zero-valent Al (ZVAl), its ability to reduce Cr(VI), a widespread pollutant, to less toxic Cr(III) remains to be uncovered. In the present study, Cr(VI) reduction by ZVAl was conducted to evaluate the potential application of Al as a reductant for Cr(VI). Polyoxometalate (POM, HNa(2)PW(12)O(40)), a catalyst, was used to accelerate Cr(VI) reduction by Al. The reaction of 0.192mM Cr(VI) on ZVAl was investigated in the presence of N(2) or O(2) at pH 1. A slight decrease in Cr(VI) concentration was observed on as-received (uncleaned) ZVAl due to the presence of oxide layer with a low surface area (ca. 3.4x10(-3)m(2)/g) of ZVAl. On addition of 0.1mM POM, Cr(VI) reduction on uncleaned ZVAl increased significantly. This is attributed to the unique properties of POM, which has a Brphinsted acidity higher than usual inorganic acids such as H(2)SO(4) and HCl. Thus, POM could remove rapidly the oxidize layer on ZVAl, followed by acting as a shuttle for electron transfer from ZVAl to Cr(VI). Under a N(2) atmosphere, one- or two-electron reduction of POM by ZVAl was responsible for Cr(VI) reduction in the early stage of the reaction. However, during reaction with ZVAl over 120min, three-electron reduction of POM predominated over Cr(VI) reduction. On interaction of O(2) with reduced POM, the formation of H(2)O(2) was responsible for subsequent Cr(VI) reduction. The results suggest that POM is an efficient catalyst for Cr(VI) reduction by Al due to the extremely rapid consumption of reduced POM or H(2)O(2) by Cr(VI).

Effects of cryoprotectant on the embryos of banded coral shrimp (Stenopus hispidus); preliminary studies to establish freezing protocols

The addition of cryoprotectants is a necessary step in cryopreservation procedures because they can minimize cellular injury during cryopreservation. Toxicity of cryoprotectant depends on the type, concentration, temperature and exposure period. The aim of this study was to investigate the toxicity of cryoprotectant to embryos of banded coral shrimp (Stenopus hispidus) in order to inform the development of a cryopreservation protocol. Three stages of embryonic development (eye-formation, heart beat and pre-hatch stage) embryos were selected and exposed to different concentration of cryoprotectants (0.25M-5M) for an equilibration period of 10, 20 or 30 min at room temperature. Hatching percentage indicated that the toxicity of tested cryoprotectants increased in the order of methanol, ethylene glycol (EG), dimethyl sulphoxide (DMSO), glycerol and dimethylacetamide (DMA). The No Observed Effect Concentrations (NOECs) for eye-formation stage embryos were 1M, 0.25M, 0.25M, 0.25M and 0.25M respectively after 10 min incubation whilst the NOECs for heart beat and pre-hatch stage embryos were 1M, 0.5M, 0.5M, 0.5M and 0.25M respectively. Pre-hatch stage embryos appeared to be more tolerant to cryoprotectant toxicity than eye-formation and heart beat stage embryos.

Toxic effects of two acid sulfate soils from the Dabaoshan Mine on Corymbia citriodora var.variegata and Daphnia carinata

Acidic, metal-stressed conditions encountered in the acid sulfate soils significantly inhibited the growth of Corymbia citriodora var.variegata, possibly due to the reduced rate of photosynthesis and plant root activity. However, the plant's self-protection mechanism to counteract stress-induced cellular damage by reactive oxygen species still functioned well even at a soil pH as low as 2.81. This may explain the high tolerance of this plant species to the extremely acidic environments. The observed phytotoxicity symptoms were not accompanied by elevated concentrations of heavy metals in the plant tissues, suggesting that heavy metal levels in plant tissue alone are not valid indications of phytotoxicity to the tested plant species. Leachates from the acid sulfate soils had strong toxicity to Daphnia carinata. Median lethal dilution factor (LDF50) was much higher for the leachate from the highly acidic acid sulfate soils (ASS) than that from the mildly acidic ASS. Although the concentration of various metals markedly decreased with increasing number of leaching cycle, leachate toxicity to Daphnia carinata did not decrease accordingly. This suggests that levels of heavy metals and Al in the leachate are not good indicators of the mine water biotoxicity.

The OptIPuter microscopy demonstrator: enabling science through a transatlantic lightpath

The OptIPuter microscopy demonstrator project has been designed to enable concurrent and remote usage of world-class electron microscopes located in Oxford and San Diego. The project has constructed a network consisting of microscopes and computational and data resources that are all connected by a dedicated network infrastructure using the UK Lightpath and US Starlight systems. Key science drivers include examples from both materials and biological science. The resulting system is now a permanent link between the Oxford and San Diego microscopy centres. This will form the basis of further projects between the sites and expansion of the types of systems that can be remotely controlled, including optical, as well as electron, microscopy. Other improvements will include the updating of the Microsoft cluster software to the high performance computing (HPC) server 2008, which includes the HPC basic profile implementation that will enable the development of interoperable clients.

Detection of locally advanced breast cancer in the I-SPY TRIAL (CALGB 150007/150012, ACRIN 6657) in the interval between routine screening

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Background: It is assumed that most locally advanced breast cancers (LABC) could be detected at an earlier stage with routine screening. However, LABCs may present between screens as interval cancers (IC). ICs present at an earlier age, with higher grade, larger size, and are associated with lower survival, compared to screen-detected cancers (SDC), and comprise 17% of cancers from population-based screening programs. We evaluated the screening history in patients with LABCs from the I SPY TRIAL, to determine the frequency of screening and ICs. Methods: Of 221 pts enrolled in the I-SPY TRIAL, a multisite neoadjuvant study for women with LABCs > 3cm in size, screening history and presentation were retrospectively collected for 154. Two groups, screened (S), defined as a mammogram within 2 years, or non screened (NS), previous mammogram more than 2 years prior, were evaluated (Table). The frequency of ICs at 1 and 2 years was determined in S pts. Frequency of mammographically occult (MO) tumors was determined for all. Results: Of the total, 99 (64%) and 55 (36%) were NS and S, respectively. Mean tumor size for all pts was 6.7cm. Only 11 (20%) of S pts were SDCs and 44 (80%) were ICs, with 24 (63%) diagnosed within 1 year and 14 (37%) between 1 and 2 yrs of their last normal mammogram. 24 (24%) NS patients were younger than the recommended screening age of 40; in the remaining 75 pts, 9 (12%) were MO. Only 20% of IC tumors were MO. ICs were of higher grade (44% vs 11% grade III), and tumor size (7.0cm vs 4.4cm) than their SDC counterparts. 80% of cancers detected in I SPY were NKI70 gene test poor prognosis. Relationship to breast density and subtype is currently being assessed. Conclusions: Women presenting with LABCs have a high likelihood (80%) of an IC. This suggests that the growth rate of LABCs precludes early detection by conventional screening. Understanding the biology of ICs will be important to develop better strategies for prevention and early detection.

[Table: see text]

No significant financial relationships to disclose.

Evaluation of the effect of screening on the detection of good and poor prognosis breast cancers

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Background: Since the advent of screening, breast cancer incidence has significantly increased in the United States as well as other countries. SEER data from the US shows that the increase is largely in localized disease without a concomitant or significant decrease in regionalized disease. In addition, the increase has occurred essentially in women over 50. We asked whether molecular characterization of tumors would shed light on the types of tumors detected in screening and in locally advanced breast cancers (LABC). Methods: We identified two groups of patients from European studies before and after the introduction of population based screened (in 1995) where the 70-gene prognosis test (MammaPrint) results were available. The first source is the European Validation Study (EVS) (Buyse et al, J Natl Cancer Inst. 2006). The second was a prospective implementation trial of MammaPrint in the Netherlands (RASTER study) (Bueno de Mesquita et al, Lancet Oncol. 2007). The source of LABC patients comes from the multicenter I-SPY TRIAL (CALGB 150007/150012) who underwent routine screening (prior mammogram within 2 years of diagnosis). Results: In women age 50–60, the fraction of cancers that were MammaPrint good prognosis were 40% and 60% prior to and after the introduction of screening, respectively. For women 50–60 who were actually undergoing screening, the fraction of tumors that were MammaPrint good prognosis was 67%. For patients aged 30–40 with stage I and II lymph node-negative disease, who did not undergo screening in either period, the fraction of MammaPrint good prognosis tumors did not change (29% and 31%, for EVS and Raster, respectively). For patients with LABC, from the I-SPY TRIAL, the fraction of tumors that are MammaPrint good prognosis is 7% and 29% for women aged 30–40 and 50–60, respectively. Of the LABC patients undergoing screening, 80% presented clinically during the interval between routine mammograms. Conclusions: Current screening programs are increasing the burden of low-risk cancers. Screening programs should consider including molecular profiles at the time of diagnosis to reduce overtreatment. The majority of LABCs have high-risk molecular profiles and do not present as screen detected cancers. New strategies are needed for early detection of LABC.

[Table: see text]

Protective role of silibinin on matrix metalloproteinase-2 and activator protein-1 on LoVo cells

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Background: Silibinin, a flavonoid and the major active component of milk thistle, has been as a safe diet supplement for several decades. It has been proved with anti-hepatotoxic properties and pleiotropic anticancer capabilities. Current study aimed to investigate the role of silibinin as potential therapeutic target of colon cancer through antiangiogenesis and its related molecular mechanisms with matrix metalloproteinase- 2 (MMP-2) and activator protein-1 (AP-1). Colon cancer cell line, LoVo cells, treated with a major prognostic factor, interleukin-6 (IL-6), was studied. Methods and Results: By western blot analysis, silibinin suppressed MMP- 2 protein expression in time- and concentration-dependent manners. Furthermore, the inhibitors of JNK/AP-1 binding activity abolished the expression of MMP-2 in IL-6-stimulated LoVo cells, but not PI3K pathways. We also demonstrated that silibinin inhibited IL-6- stimulated LoVo cell migration and further tumor angiogenesis, which similar to the effects from addition with AP-1 inhibitor. By EMSA, the binding activity of AP-1 in LoVo cells was also decreased with silibinin treatment. In addition, the imaging of confocal microscopy revealed that AP-1 presentation was attenuated on IL-6-stimulated LoVo cells plus silibinin treatment. Conclusions: Taken together, these data indicated that silibinin inhibits angiogenesis through the suppression of MMP-2 expression and AP-1 binding activity in colon cancer cells. It suggests a novel anti-metastatic application of silibinin in colon cancer chemoprevention.

No significant financial relationships to disclose.

Induction chemotherapy followed by concurrent chemoradiotherapy with/without esophagectomy for locally advanced esophageal squamous cell carcinoma

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Background: To assess the feasibility of preoperative induction chemotherapy in addition to concurrent chemoradiotherapy (CCRT) followed by esophagectomy if possible for locally advanced esophageal squamous cell carcinoma (ESCC) with a special emphasis on M1a or nodal M1b disease. Methods: Patients who had histologic proof of T3N1M0, M1a, or nodal M1b ESCC first received up to 3 courses of induction chemotherapy (paclitaxel 70 mg/m2 or docetaxel 40 mg/m2 IV 1-hr D 1, 8; cisplatin 35 mg/m2 IV 2-hr D 1, 8; 5-fluorouracil 2000 and leucovorin 300 mg/m2 IV 24-hr D 1, 8; repeated every 28 days). This was followed by CCRT (paclitaxel 35 mg/m2 1-hr D 1, 4 /wk, cisplatin 15 mg/m2 1-hr D 2, 5/wk, and radiotherapy 2 Gy D 1–5 /wk) (Lin CC et al. Ann Oncol 18:93–8,2007). When the accumulated radiation dose reached 40 Gy, the feasibility of esophagectomy was evaluated in all patients. In patients for whom esophagectomy was not feasible, CCRT was continued to a dose of 60 Gy. Results: Fifty-six patients (M:F = 51:5, median age 58, range 41–78) with locally advanced (T3N1M0:M1a:M1b[nodal] = 30:7:19) ESCC (upper:mid:lower = 15:25:16) were enrolled from June 22, 2006 to December 17, 2008. By December 31, 2008, 10 patients are still under protocol treatment. Eighteen (T3N1:M1a:M1b[nodal] = 14:3:1) (40%) and 20 of 46 patients underwent surgery and continued CCRT up to 60 Gy, respectively. Nine (T3N1:M1a:M1b[nodal] = 7:2:0) (20%) and 5 patients had pathologic complete response and microscopic residual disease, respectively. With a median follow-up of 8.4 months (range 0.5–30.8), 17 (T3N1:M1a:M1b[nodal] = 9:2:6) patients had relapse. Four and 13 patients had local recurrence and distant metastasis, respectively. The median progression-free survival was 20.3 months. The median overall survival had not reached yet with 1- and 2-year overall survival being 76 and 57%, respectively. There was no difference in progression- free or overall survival among patients with T3N1M0, M1a, or nodal M1b disease. Conclusions: Three-step strategy of preoperative taxane-based induction chemotherapy then CCRT followed by esosphagectomy if possible appears quite active in locally advanced ESCC patients with 46% having M1a or nodal M1b disease.

No significant financial relationships to disclose.

Evaluation of estrogen receptor expression as a prognostic factor for very young women (below 35 years) with breast cancer in Taiwan

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Background: In the past two decades, the incidence of very young (<35 years) breast cancer in Taiwanese has been rapidly increasing to quite close to that of Caucasian Americans. However, the clinicopathological features of this group of patients appear to be different from their Western counterpart. Here, we sought to determine the prognostic value of ER expression for this newly emerging population in Taiwan. Methods: We retrospectively collected information on all consecutive very young patients (age <35 years) with stage I-III breast cancer treated at National Taiwan University Hospital between 1997 and 2005. ER expression was evaluated by immunohistochemistry on formalin-fixed paraffin-embedded tissue sections. Tumor with more than 10% positive nuclei was considered ER positive. Results: A total of 178 patients with a median age of 32 (range: 21–35) years were included. The median follow-up time was 62.5 (95% confidence interval, 42.0–64.2) months. Univariate analysis showed that ER expression was significantly associated with favorable OS (HR=0.48, P=0.03), but not with DFS (hazard ratio [HR]=0.79, P=0.42). Multivariate analysis showed that stage and ER were independent prognostic factors. Conclusions: In contrast to the findings in Caucasians, ER expression was an independent prognostic factor for favorable overall survival in Taiwanese patients with very young breast cancer.

No significant financial relationships to disclose.

Helicobacter pylori-independent MALT lymphoma patients responsive to thalidomide—the molecular mechanism and the clinical application

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Background: We have recently demonstrated that nuclear expression of BCL10 or NF-κB helps predict H. pylori-independent status; and inflammatory cytokines such as TNF-α may be related to BCL10 nuclear translocation (Blood 2005;106:1037–41;J Biol Chem 2006;281:167–75). Recent studies have been shown that the chimeric protein of t(11;18)(q21;q21) can lead to constitutive NF-κB activity and thereby mediate cell survival and anti-apoptotic signals. The present study was conducted to investigate the molecular mechanism and the clinical efficacy of thalidomide, an TNF-α or NF-κB inhibitor, in H. pylori-independent MALT lymphoma. Methods: Between October 2003 and June 2007, our study enrolled 11 H. pylori-independent MALT lymphoma patients ( 7 men and 4 women; age range, 43 to 79 years; 7 patients who had failed chemotherapy or rituximab) with nuclear expression of BCL10 or NF-κB in pretreatment lymphoma tissues treated at National Taiwan University Hospital with thalidomide 100mg to 200 mg oral given daily. The presence of t(11;18)(q21;q21) was identified by a multiplex reverse transcriptase polymerase chain reaction of the API2-MALT1 chimeric transcript. Results: Three (27.3%) of 11 patients achieved a complete response (CR), and 3 (27.3) of 11 patients achieved a partial response (PR), resulting in an overall response rate of 54.5% (95% CI, 19.5%-89.6%). The median time from thalidomide therapy to CR was 3.0 months (range, 2.7–4.9 months). At a median follow-up of 41.6 months (range, 17.7–63.8 months), the 3-year event-free survival and overall survival after thalidomide treatment was 80.8%, and 88.9%, respectively. The API2-MALT1 fusion transcript for t(11;18)(q21;q21) was detected in 1 (16.7%) of 6 patients with CR or PR, and 4 (80.0%) of 5 patients with stable or progressive disease (P = 0.08). Conclusions: Our results indicate that thalidomide can be an adjuvant treatment for H. pylori-independent MALT lymphoma patients. Additional investigation of the molecular mechanisms and biologic significance of the API2-MALT1 fusion transcript responsible for thalidomide resistance in this group of tumors is needed.

No significant financial relationships to disclose.

Phase II study of cetuximab plus weekly cisplatin and 24-hour infusion of high-dose 5-fluorouracil and leucovorin for the first-line treatment of advanced gastric cancer

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Background: Cisplatin-HDFL regimen, using weekly 24-hour infusions of cisplatin and high-dose 5-fluorouracil (5-FU) and leucovorin, is commonly used in Taiwan for patients with advanced gastric cancer (GC), showing an overall response rate of approximately 60% (95% CI: 45%-76%) [J Clin Oncol (Suppl) 2006; 24(18S): A14063 ]. We have demonstrated that cetuximab is cytotoxic to human GC cells, and has a chemosensitizing effect for cisplatin and 5-FU in GC cells [Proc AACR 2006; 47: A1233]. Methods: All patients had pathologically confirmed metastatic/ recurrent chemonaive GC, at least 1 measurable lesion, a fasting serum triglyceride level > 70 mg/dl, WHO PS 0/1/2, adequate hepatic, renal, and bone marrow functions. Cetuximab 400 mg/m2 was given as 2h infusion, initially (i.e., D1 of cycle 1); and followed by weekly 1h infusion of 250 mg/m2 (i.e., D8, D15, D22 of cycle 1, and D1, D8, D15, D22 of cycle 2). Cisplatin 35 mg/m2 was given as a 24h infusion, admixing with 5-FU 2,000 mg/m2 and leucovorin 300 mg/m2 (HDFL), D1, D8. A 24h infusion of HDFL was given on D15. Cycles were repeated every 28 days, and response evaluation was performed every 2 cycles & at the end of protocol treatment. The primary end-point was confirmed objective response rate (RR) by RECIST. Results: Between Dec. 2005 and Nov. 2008, 35 patients (M:19, F:16) with a median age of 56 (40–74) were enrolled and evaluable for response assessment. The overall RR was 68.6% (51–83%, 95% C.I.) with 1 CR and 23 PRs. Among a total of 269 cycles (median: 7, range: 2 to 22+ cycles) given, Gr3/4 neutropenia, infection, and hepatic toxicity developed in 6.0%, 4.8%, and 0.74% of 269 cycles, respectively. Two patients have developed acute hepatitis B flare-up among seven HBsAg (+) carriers, and were well controlled by lamivudine. Gr1, Gr2, and Gr3 acne- like rashes have developed in 57.1%, 31.4%, 5.7%; and Gr1, Gr2, Gr3 paronychia have developed in 40.0%, 8.6%, and 2.9% of 35 patients, respectively. Median PFS (range: 3 to 22+ months) and median OS (range: 3 to 35+ months) was11.0 and 14.5 months, respectively. Conclusions: Cetuximab plus infusional cisplatin-HDFL is a highly effective regimen with low toxicity and favourable survival in the first-line treatment of advanced GC.

No significant financial relationships to disclose.

MicroRNAs 15a and 16–1 regulates tumor proliferation in multiple myeloma

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Background: MicroRNAs (miRNAs) are non-coding RNAs that act as negative regulators of gene expression. They have been described to play roles in solid tumors and hematologic malignancies. However the role of miRNAs in multiple myeloma (MM) has not been yet fully described. Methods: We performed miRNA-profiling of primary bone marrow-derived CD138+ MM cells, compared to their normal cellular counterparts and validated data by qRT-PCR. In vitro and in vivo functional studies were performed on miRNA-15a- and -16–1-precursors-transfected MM cells. Effect of miRNA-15a and -16–1 on signaling cascades have been evaluated by western blot and immunofluorescence. NF-kB activity has been studied using the Active Motif TransAM kit. In vivo MM cell growth has been evaluated by either using an in vivo imaging model or bioluminescence. Angiogenesis has been studied both in vitro and in vivo using the chorioallantoic membrane model. Results: We identified a MM-specific miRNA signature characterized by down-expression of miRNA-15a, -16–1 and over-expression of miRNA-222/-221/-382/-181a/-181b (P<0.01). Data were confirmed by qRT-PCR on matched samples. Predicted targets for the decreased miRNAs in MM patients included pro-angiogenic cytokines, oncogenes, cell cycle regulators, NFkB activators. Conversely, predicted targets for the increased miRNAs included cell cycle inhibitors, suppressors of cytokine signaling, and pro-apoptotic factors. We demonstrated that miRNA-15a and - 16–1 regulate proliferation and growth of MM cells. Indeed, transfected cells showed decreased DNA synthesis; decreased cyclinD1/cyclinD3/CDC25a/pRb protein expression; phase G1 cell cycle arrest. Moreover, transfected cells showed inhibition of NFkB pathway as shown by reduced p65-/p50-/p52-NFkB activities; downregulation of p-p65/p50/p52 nuclear protein level; upregulation of cttosolic phospho-IkB; and inhibited translocation of p-p65 from the cytolplasm to the nucleus. Similarly, inhibition of MM cell growth was confirmed in vivo; and anti-angiogenic properties of miRNA-15a and -16–1 were demonstrated both in vitro and in vivo. Conclusions: These data indicate that miRNAs play a pivotal role in the biology of MM; providing the basis for the development of new miRNA-based targeted therapies in this disease.

No significant financial relationships to disclose.