Differential expression of small ubiquitin-like modifier family of proteins in patients with colorectal adenocarcinoma

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Background: The cytotoxic effects of radiation and chemotherapy are mediated in part by DNA damage. The small ubiquitin-like modifier (SUMO) family of proteins regulates DNA repair pathways by activating factors involved in homologous recombination (HR) or non- homologous end joining (NHEJ). Our objective was to determine the potential role of SUMO proteins in patients with colorectal cancer.

Methods: We first assessed two established colorectal cancer cell lines (HCT116 and HT29) and two normal colonic mucosa cell populations utilizing ultra high-throughput expression analysis (Solexa) to examine differential expression of genes involved in SUMOylation (SAE1, SAE2, PIAS-1, and DNAPKcs). To verify the clinical relevance of SUMOylation in colorectal cancer, we obtained archived specimens from patients with colorectal cancer (n=51) and examined the expression of these proteins in both benign and malignant tissue by immunohistochemistry (IHC).

Results: Ultra high-throughput expression analysis of cancer and normal cells revealed a 10 to 15-fold upregulation of SAE2 (heterodimer of the E1 activation enzyme in SUMOylation), a 10 to 11-fold upregulation of DNAPKcs (catalytic subunit in NHEJ repair pathway), and a 6-fold upregulation of SAE1 in cancer cells. In contrast, PIAS-1 showed similar expression levels between cancer and normal colonic cells. By IHC, SAE1 and SAE2 were highly expressed in 65% and 53% of tumor specimens, respectively; but only in 7% and 0% of normal tissues, respectively. DNAPKcs was also highly expressed in tumor tissues (63%) with corresponding low expression (0%) in normal tissues. Corroborating the cell line results, PIAS-1 was infrequently expressed in both tumor (10%) and normal tissues (0%).

Conclusions: We are the first to demonstrate the differential expression of SUMO proteins in colorectal cancer cell lines and in clinical specimens. SUMO proteins have a role in DNA repair and their expression in colorectal cancer may modify tumor response to chemoradiotherapy.

No significant financial relationships to disclose.

The CKLF1-C19 peptide attenuates allergic lung inflammation by inhibiting CCR3- and CCR4-mediated chemotaxis in a mouse model of asthma

BACKGROUND

  Human chemokine-like factor 1 (CKLF1) is a functional ligand for human CCR4, which is highly expressed on Th2 lymphocytes and plays an important role in the pathogenesis of asthma. The expression and function of CKLF1 are associated with asthma. The CKLF1 C-terminal peptides C19 and C27 also interact with human CCR4. Albeit with weaker chemotactic activity, C19 can inhibit chemotaxis induced by both CKLF1 and CCL17. Here, we explore whether C19 can act as an antagonist in the development of asthma.

METHODS

  A mouse model of asthma and in vitro and in vivo chemotaxis assays were used.

RESULTS

  Using a mouse model of asthma, we demonstrate here that C19 reduces airway eosinophilia, lung inflammation and airway hyperresponsiveness; in contrast, C27 has little effect on these parameters. The inhibitory effects of C19 on CCR4-mediated chemotaxis could be observed in human Th2 lymphocytes and in the splenocytes from ovalbumin-sensitized mice. Furthermore, we show that C19 can inhibit CCL11-induced chemotaxis of mouse eosinophils and human CCR3-transfected or mouse Ccr3-transfected HEK293 cells. In vivo chemotaxis assays revealed that C19 and C27 can reduce CCL11-mediated recruitment of eosinophils into the peritoneal cavity and that this inhibitory effect is stronger for C19 than for C27.

CONCLUSIONS

  Thus, C19 can attenuate airway eosinophilia and lung inflammation by inhibiting CCR3- and CCR4-mediated chemotaxis in a mouse model of asthma. Given its ability to inhibit human CCR3- and CCR4-meditated chemotaxis, C19 has great therapeutic potential for use in the treatment and control of allergic asthma.

Use of the XRCC1 single nucleotide polymorphism to predict pathologic complete response to neoadjuvant chemoradiation in stage II/III rectal cancer

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Background: The X-ray repair cross-complementing protein 1 (XRCC1) gene plays an important role in DNA damage repair; and the R194W and R399Q single nucleotide polymorphisms (SNPs) are associated with attenuated DNA repair activity. Our objective was to determine whether XRCC1 SNPs were associated with response to neoadjuvant chemoradiation therapy (CRT) in rectal cancer patients.

Methods: We conducted a prospective multicenter phase II trial to investigate the effect of additional chemotherapy with a longer CRT-to-surgery interval on treatment response in patients with rectal cancer. Paired normal and rectal cancer tissues were prospectively collected from enrolled patients (n=110). DNA was extracted from normal rectal mucosa and analyzed for XRCC1 R194W and R399Q by polymerase chain reaction and sequencing. Each SNP was compared to response to CRT. Response to CRT was determined by a central pathologist.

Results: Of the 110 patients, 25% (n=27) achieved a pathologic complete response (pCR). We examined the XRCC1 R194W SNP and observed that the allelic frequency of patients with the R/R genotype was 84% (n=92), the R/W genotype was 14% (n=16), the W/W genotype was 1% (n=2). By Fisher's Exact test, patients harboring either the R/W or W/W genotype, had a significantly higher rate of pCR compared to patients with the R/R genotype (44% vs. 21%, respectively; p=0.04). We then examined the R399Q SNP and observed that the allelic frequency of patients with the R/R genotype was 34% (n=37), the R/Q genotype was 49% (n=54), and the Q/Q genotype was 17% (n=19). In contrast, the detection of XRCC1 R399Q SNPs was not associated with pCR.

Conclusions: We demonstrate that XRCC1 R194W SNP is associated with increased rate of pCR in our prospective multi-center trial. Although the detection of XRCC1 R399Q SNP is not associated with pCR, the detection of XRCC1 SNPs that predict treatment response may help identify patients who are unlikely to respond to CRT and therefore may potentially avoid treatment-associated morbidities.

No significant financial relationships to disclose.

Adjuvant chemotherapy for gastric cancer: Less drug, same efficacy

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Background: Adjuvant chemotherapy is proved to improve survival in gastric cancer by meta-analyses. However, no evidence showed the best regimen. We conducted a retrospective analysis to compare triplets with doublets in the adjuvant setting.

Methods: We collected data from January 2004 to December 2008 from patients performed radical surgery and adjuvant chemotherapy. Doublets were defined as 5-FU 750 mg/m2 (d1- 5) or capecitabine 1,000 mg/m2 (d1-14) plus cisplatin 60 mg/m2 (d1) or oxaliplatin 130 mg/m2 (d1), while triplets had epirubicin 50 mg/m2 (d1) added. Chemotherapy was initiated within 6 weeks after surgery, repeated every three weeks and planned for 6 cycles. Patients were followed up in the outpatient clinic until death or April 30, 2010. Cox proportional-hazard model and chi-square test were used to test statistical difference.

Results: A total of 316 patients (210 in doublets, 106 in triplets) had a median follow-up time of 47 months. 77 patients died at the end of follow-up (3-year survival of 67.4%).Two groups were well balanced except age (median age of 57 in doublets, 51 in triplets, p < 0.001). All the patients tolerated well, with few grade 3/4 side effects (21.9% in doublets, 30.2% in triplets, p = 0.107). Two groups had similar disease-free survival (median DFS, 16 months vs. 23 months, p = 0.656) and overall survival (3-year survival rate, 59.6% vs. 64.8%, p = 0.293). Subgroup analysis showed the same benefit on survival between the two groups.

Conclusions: Our study suggested doublets and triplets had the same efficacy as the adjuvant chemotherapy. Furthermore, doublets seem more cost-effective.

[Table: see text]

No significant financial relationships to disclose.

Use of genetic variations to predict toxicity associated with neoadjuvant chemoradiation for AJCC stage II/III rectal cancer

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Background: Genetic polymorphisms have been associated with toxicity from chemotherapeutic agents for colon cancer, but none has been identified for rectal cancer. We examined the association between polymorphisms in genes for DNA repair, cell cycle progression, angiogenesis, and drug metabolism with toxicity from neoadjuvant chemoradiation treatment (CRT) for rectal cancer.

Methods: Patients with AJCC stage II/III rectal adenocarcinoma were enrolled in a phase II multicenter trial examining timing of rectal cancer response to neoadjuvant CRT. There were two treatment arms: (I) radiation (XRT) and 5-FU followed by surgery and (II) XRT/5-FU and FOLFOX followed by surgery. Treatment toxicity, classified by the NCI Common Terminology Criteria guidelines as grade 3 and above, was recorded. DNA was extracted from normal rectal mucosa and analyzed for 22 polymorphisms in 17 genes.

Results: We evaluated 110 patients (group I, n = 52; group II, n = 58). A total of 19 patients experienced grade 3+ adverse events (AE) [group I, n = 10 (19%); group II, n = 9 (16%)]. Gastrointestinal symptoms were the most common AE [group I, n = 5 (10%); group II, n = 4 (7%)]. The detection of lys allele (lys/lys or lys/gln genotypes) at codon 751 of the Xeroderma pigmentosum group D (XPD) gene was associated with increased toxicity in group II (p = 0.03), whereas homozygosity for the arg allele (i.e., arg/arg genotype) at codon 399 of the X-ray cross-complementing protein 1 (XRCC1) gene was associated with a significant increase in toxicity in both treatment groups (p = 0.009).

Conclusions: Genetic polymorphisms in DNA damage repair genes XPD and XRCC1 are associated with toxicity in rectal cancer patients receiving CRT. The identification of gene polymorphisms that predict adverse events may help to optimize patient therapy while minimizing morbidities.

No significant financial relationships to disclose.

CIP2A is over-expressed in acute myeloid leukaemia and associated with HL60 cells proliferation and differentiation

INTRODUCTION

CIP2A is a newly identified inhibitor of PP2A. It can stabilize c-Myc and promote anchorage-independent cell growth and tumour formation. CIP2A is over-expressed in some solid tumours although its expression in acute myeloid leukaemia (AML) is still unknown.

METHODS

CIP2A mRNA and protein expressions were determined in bone marrow mononuclear cells of both patients with AML and healthy controls using reverse transcription polymerase chain reaction and Western blot, respectively. We used siRNA to knock-down CIP2A expression in HL60 cells and then examined its potential roles during the pathological progression of AML.

RESULTS

CIP2A mRNA was present in 54 of 70 (77.14%) patients with newly diagnosed AML and in 11 of 14 (70.86%) patients with relapsed AML, which was significantly higher than complete remission specimens and healthy controls (P<0.001). Knock-down of CIP2A in HL60 cells slowed down cell proliferation, decreased clonogenic activity and promoted cell differentiation.

CONCLUSION

These results suggest that CIP2A is over-expressed in patients with newly diagnosed/relapsed AML and the expression of CIP2A could have potential use as a clinical marker for AML relapse after treatment. The high expression of CIP2A in HL60 cells may be related to active cell proliferation and arrest of cell differentiation. This study may shed light on the molecular function of CIP2A in myeloid leukemogenesis.

LITAF and TNFSF15, two downstream targets of AMPK, exert inhibitory effects on tumor growth

Lipopolysaccharide (LPS)-induced tumor necrosis factor (TNF) α factor (LITAF) is a multiple functional molecule whose sequence is identical to the small integral membrane protein of the lysosome/late endosome. LITAF was initially identified as a transcription factor that activates transcription of proinflammatory cytokine in macrophages in response to LPS. Mutations of the LITAF gene are associated with a genetic disease, called Charcot-Marie-Tooth syndrome. Recently, we have reported that mRNA levels of LITAF and TNF superfamily member 15 (TNFSF15) are upregulated by 5' adenosine monophosphate (AMP)-activated protein kinase (AMPK). The present study further assesses their biological functions. Thus, we show that 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR), a pharmacological activator of AMPK, increases the abundance of LITAF and TNFSF15 in LNCaP and C4-2 prostate cancer cells, which is abrogated by small hairpin RNA (shRNA) or the dominant-negative mutant of AMPK α1 subunit. Our data further demonstrate that AMPK activation upregulates the transcription of LITAF. Intriguingly, silencing LITAF by shRNA enhances proliferation, anchorage-independent growth of these cancer cells and tumor growth in the xenograft model. In addition, our study reveals that LITAF mediates the effect of AMPK by binding to a specific sequence in the promoter region. Furthermore, we show that TNFSF15 remarkably inhibits the growth of prostate cancer cells and bovine aortic endothelial cells in vitro, with a more potent effect toward the latter. In conjuncture, intratumoral injection of TNFSF15 significantly reduces the size of tumors and number of blood vessels and induces changes that are characteristic of tumor cell differentiation. Therefore, our studies for the first time establish the regulatory axis of AMPK-LITAF-TNFSF15 and also suggest that LITAF may function as a tumor suppressor.

Search for stopped Gluinos in pp collisions at square root s=7 TeV

The results of the first search for long-lived gluinos produced in 7 TeV pp collisions at the CERN Large Hadron Collider are presented. The search looks for evidence of long-lived particles that stop in the CMS detector and decay in the quiescent periods between beam crossings. In a dataset with a peak instantaneous luminosity of 1×10(32) cm-2 s-1, an integrated luminosity of 10 pb-1, and a search interval corresponding to 62 hours of LHC operation, no significant excess above background was observed. Limits at the 95% confidence level on gluino pair production over 13 orders of magnitude of gluino lifetime are set. For a mass difference mg - mχ1(0) >100 GeV/c2, and assuming BR(g→gχ1(0))=100%, mg < 370 GeV/c2 are excluded for lifetimes from 10 μs to 1000 s.

Search for quark compositeness with the dijet centrality ratio in pp collisions at √s=7 TeV

A search for quark compositeness in the form of quark contact interactions, based on hadronic jet pairs (dijets) produced in proton-proton collisions at √s=7 TeV, is described. The data sample of the study corresponds to an integrated luminosity of 2.9 pb(-1) collected with the CMS detector at the LHC. The dijet centrality ratio, which quantifies the angular distribution of the dijets, is measured as a function of the invariant mass of the dijet system and is found to agree with the predictions of the standard model. A statistical analysis of the data provides a lower limit on the energy scale of quark contact interactions. The sensitivity of the analysis is such that the expected limit is 2.9 TeV; because the observed value of the centrality ratio at high invariant mass is below the expectation, the observed limit is 4.0 TeV at the 95% confidence level.

Aggressive angiomyxoma of the vulva: case report and literature review

Aggressive angiomyxoma is a rare softtissue tumour, typically occurring in the female pelvis and carrying a high risk of local infiltration and relapse. Surgery remains the first line of treatment, however some adjuvant treatments, such as gonadotrophin-releasing hormone (GnRH) agonists, have been used for primary treatment and for treatment against tumour recurrence. We describe a case of vulvar aggressive angiomyxoma in a 31-year old woman who underwent surgical excision of the tumour. Diagnosis was made on the basis of histopathological examination and positive immunohistochemical staining with oestrogen and progesterone receptors. Postsurgery, a GnRH agonist (3.75 mg triptorelin) was injected intramuscularly every month for 3 months to prevent tumour recurrence and, to date, no relapse has been observed. Whether treatment is with surgery, hormone therapy or both, it is clear that aggressive angiomyxoma requires close, long-term follow-up to monitor for disease recurrence and that the individualization of each case is essential for adequate management.

Lung cancer and occupational exposures other than cotton dust and endotoxin among women textile workers in Shanghai, China

OBJECTIVES

Numerous epidemiological studies of lung cancer among textile workers worldwide consistently indicate reduced risks related to cotton dust exposure, presumably due to endotoxin contamination. Our objective was to investigate associations with other exposures potentially related to lung cancer, including wool and synthetic fibre dusts, formaldehyde, silica, dyes and metals, that have only been studied to a limited extent in the textile industry.

METHODS

We conducted a case-cohort study nested within a cohort of 267,400 women textile workers in Shanghai, China. We compared work assignments and exposure histories of 628 incident lung cancer cases, diagnosed during 1989-1998, with those of a reference subcohort of 3188 workers. We reconstructed exposures with a job-exposure matrix developed specifically for textile factories. Cox proportional hazards modelling was applied to estimate age/smoking-adjusted relative risks (hazard ratios) and risk gradients associated with job assignments and specific agents other than cotton dust and endotoxin.

RESULTS

No associations were observed for lung cancer with wool, silk or synthetic fibre dusts, or with most other agents. However, increased risks, although statistically imprecise, were noted for ≥ 10 years' exposures to silica (adjusted HR 3.5, 95% CI 1.0 to 13) and ≥ 10 years' exposures to formaldehyde (adjusted HR 2.1, 95% CI 0.4 to 11).

CONCLUSIONS

Exposures to silica and formaldehyde, although not widespread among the cohort, may have increased lung cancer risk. Silica is an established human lung carcinogen, whereas there is only weak prior evidence supporting an association with formaldehyde. Both exposures warrant consideration as potential lung carcinogens in textile manufacturing.

Differential Levels of Cytokines and Soluble Fas Ligand between Tuberculous and Malignant Effusions

Tuberculous pleurisy, which is characterized by an extensive inflammatory exudate in the pleural space, is a common manifestation of extrapulmonary tuberculosis caused by Mycobacterium tuberculosis infection but is difficult to diagnose. This study compared concentrations of three cytokines (interferon-γ and interleukin [IL]−2 and −4) and soluble Fas ligand in serum and pleural effusions from 36 patients with tuberculous pleurisy, 30 with malignant pleurisy and 30 healthy volunteers. Interferon-γ concentration was significantly higher in serum and pleural effusions, and the concentration of soluble Fas ligand was significantly higher in pleural effusion, from patients with tuberculous pleurisy than in those with malignant pleurisy. Levels of IL-2 and IL-4 were also raised in serum, but failed to reach statistical significance. Interferon-γ and soluble Fas ligand levels were significantly higher in pleural effusion than in serum. Pleural soluble Fas ligand concentrations correlated linearly with those of interferon-γ in patients with tuberculous pleurisy. These findings suggest a predominant T-helper-1 response to M. tuberculosis infection.