Expression of methylation-related genes is associated with overall survival in patients with non-small cell lung cancer

The abnormality of DNA methylation is involved in tumour progression, and thus has a modulating effect on clinical outcome of cancer patients. In this study, we measured the mRNA expression levels of three methylation-regulating genes (DNMT1, DNMT3b, and MBD2) in 148 tumour samples from patients with non-small cell lung cancer (NSCLC) using quantitative real-time polymerase chain reaction and then determined their prognostic values. Our data showed that the high level of DNMT1 expression was significantly associated with an increased risk of death in all NSCLC patients (hazard ratio (HR), 1.74; 95% confidence interval (95% CI), 1.04-2.90). However, the high level of DNMT3b expression was significantly associated with poor prognosis only in young patients (<65 years). The high level of MBD2 expression had a significantly reduced risk for death only in male patients and in squamous cell lung carcinoma (SQLC) patients. All three combination groups with DNMT1 and DNMT3b, DNMT1 and MBD2 or DNMT3b and MBD2 revealed significant combined effects in male patients and SQLC patients. Our results suggest that DNMT1, DNMT3b, and MBD2 may play important roles in modulating NSCLC patient survival and thus be useful for identifying NSCLC patients who would benefit most from aggressive therapy.

Colorectal cancer or colon and rectal cancer? Clinicopathological comparison between colonic and rectal carcinomas

AIMS

The aim of this study was to compare features of colon and rectal cancers such as prognosis, clinicopathological features and tumor markers, namely carcinoembryonic antigen (CEA), matrix metalloproteinase (MMP)-2 and p27(kip1).

METHODS

Two hundred and thirty patients with stage I-III colon or rectal cancer were retrospectively assessed with the endpoint of recurrence or metastasis after curative operation. CEA, MMP-2 and p27(kip1) were studied by immunohistochemistry in cancer tissues of all patients.

RESULTS

The disease-free 3-year survival rate after operation of the total 230 patients was 63.0%. The prognosis of colon cancer was significantly better than that of rectal cancer (70.6 vs. 57.0%; p = 0.017), especially for stage III (p = 0.0059). Multivariate analysis also demonstrated that tumor location in the colon or rectum, differentiation, venous invasion and the expression of CEA were independent factors for prognosis. The hazard of recurrence and metastasis in rectal cancer was 1.564 times that in colon cancer. In both groups, there were no statistical differences in age, gender, tumor size, tumor gross type, mucin production, tumor differentiation, venous invasion, MMP-2 and p27(kip1).

CONCLUSION

We investigated prognosis, clinicopathological factors, oncogenes and tumor suppressor gene production in colon and rectal cancers. The prognosis of colon cancer is better than that of rectal cancer, especially for stage III. This study shows some differences between colon and rectal cancer.

RNA interference against peroxisome proliferator-activated receptor delta gene promotes proliferation of human colorectal cancer cells

PURPOSE

This study was designed to investigate the effects of peroxisome proliferator-activated receptor delta (PPAR delta) on the proliferation and apoptosis of human colorectal cancer cells.

METHODS

For RNA interfering (RNAi), HCT-116 cells were transfected with short hairpin RNA (shRNA)-expressing plasmids against PPAR delta or negative control vectors, and the stably transfected cells were selected with G418. The efficacy of RNAi was assessed by real-time reverse transcription polymerase chain reaction (RT-PCR) and Western blotting analysis. The proliferation, cell cycle, and apoptosis of HCT-116 cells treated by RNAi, compared with those containing control vectors or untreated, were analyzed respectively by using MTT (methyl thiazolyl tetrazolium), flow cytometry, and TdT (terminal deoxynucleotidyl transferase)-mediated dUTP nick end-labeling (TUNEL) assay.

RESULTS

RNAi targeting PPAR delta resulted in substantial suppression of PPAR delta expression and significantly promoted the proliferation of HCT-116 cells relative to those with control vectors or untreated, obviously decreasing the frequency of G1-phase cells but had no effect on cell apoptosis.

CONCLUSIONS

PPAR delta may inhibit the proliferation of CRC cells and increase the number of cells in G1 phase, without any function in cell apoptosis.

Oncolytic adenovirus-mediated shRNA against Apollon inhibits tumor cell growth and enhances antitumor effect of 5-fluorouracil

Apollon, a membrane-associated inhibitor of apoptosis protein, protects cells against apoptosis and is upregulated in certain tumor cells. In this study, the effects of Apollon protein knockdown by RNA interference on the growth of human HeLa, HT-1080 and MCF-7 cells in vitro and in vivo were investigated. An oncolytic adenovirus (ZD55) containing the RNA polymerase III-dependent U6 promoter to express short hairpin RNA (shRNA) directed against Apollon (ZD55-siApollon) was constructed. Our data show that ZD55-siApollon successfully exerts a gene knockdown effect and causes the inhibition of tumor cell growth both in culture and in athymic mice in vivo. Cell cycle analysis, 4',6-diamidino-2-phenylindole staining and western blot analysis reveal that ZD55-siApollon-mediated suppression of Apollon induces apoptosis. Intratumoral injection of ZD55-siApollon significantly inhibits tumor growth in HT-1080 xenograft mice. Furthermore, ZD55-siApollon enhances the antitumor effect of 5-fluorouracil, a chemotherapeutic agent. In conclusion, these results suggest that the depletion of Apollon by oncolytic adenovirus-shRNA delivery system provides a promising method for cancer therapy.

Theoretical studies of the conformations and 19F NMR spectra of linear and a branched perfluorooctanesulfonamide (PFOSAmide)

Technical perfluorooctanesulfonate (PFOS) and its derivatives, such as perfluorooctanesulfonamide (PFOSA), are not clean compounds but, instead, complex mixtures of linear and branched isomers, and other compounds including sulfonate homologues. Questions have been raised as to whether the linear and the branched isomers behave differently in the environment. However, little is known about the physical properties or the finer details of the structures of the individual branched isomers. This study sought an effective computational method to model the preferred conformations of PFOS derivatives, and the energy differences between them and to determine if these results can be used to explain the temperature dependence of their NMR spectra. Good predictions of the 19F chemical shifts were obtained for some PFOSA-type molecules with a computational approach [B3LYP-GIAO/6-31++G(d,p)//B3LYP/6-31G(d,p)] that is relatively inexpensive. Large 5JFF couplings found in one of the branched isomers could be rationalized on the basis of the relevant F-F distances in the optimized structure. At low temperatures, the splitting observed in the NMR spectrum at C-1 for these sulfonamides can be explained by the existence of the two conformers predicted by the computations.

Results after change of treatment policy for rectal cancer – report from a single hospital in China

BACKGROUND

Great changes have occurred in the management of rectal cancer. This study presents the outcome of total mesorectal excision (TME) for rectal cancer in a single Chinese institution and evaluates TME's role in the comprehensive management of rectal cancer.

METHODS

We reviewed the data of rectal cancer patients surgically treated by three colorectal surgeons from January 2000 to August 2004. Patients who received surgical resection for rectal cancer from January 1996 to December 1999, before the introduction of TME, were chosen as controls. Data regarding characteristics of patients and tumors, surgical procedures, postoperative complications, and results of follow-up were collected for analysis.

RESULTS

Three hundred and seventy-seven patients with rectal cancer were enrolled in our study, with 175 patients in the TME group and 202 as controls. Mortality and morbidity rates were 1% and 14% in TME patients and 1% and 31% in controls, respectively. The TME group had a shorter operation time and hospital stay, and less bleeding, wound and urinary complications. The local recurrence (LR) rate was 6% and 12% in the TME and the control groups, respectively (P<0.05). With a median follow-up of 35 months, the actuarial 5-year survival rate was 66%. Consistent with the univariate analysis result, multivariate analysis demonstrated that TNM stage, tumor grade, age, and surgeons were independent prognostic factors. TME was not an independent prognostic factor for patients' survival.

CONCLUSIONS

TME is a safe and efficient option in reducing LR. However, it is not an independent predictor for patients' survival. In addition to the standardized usage of TME, further knowledge on the molecular mechanism of cancer is needed.

STK15 F31I polymorphisms and uterine cancer risk: A case-control analysis

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Background: STK15 is a serine threonine kinase which assists chromosomal separation and mitotic spindle stability through interaction with the centrosome during mitosis. STK15 polymorphisms have been associated with an increased risk for breast cancer in several case-control studies. We hypothesized that STK15 polymorphisms might modulate risk of uterine cancer. Methods: Uterine cancer patients treated at M. D. Anderson Cancer Center were identified from the tumor bank database from January 1, 2000 to June 30, 2006. Two common STK15 single nucleotide polymorphisms (SNPs), F31I (T/A) and V57I (G/A), were genotyped in patients with uterine cancer and in a control population matched for age, race, and smoking status. Odds ratios (OR) and 95% confidence intervals (CI) were obtained using unconditional logistic regression analysis. Results: A total of 193 women with uterine cancer and 218 controls were genotyped for both SNPs. After adjustment for age, race, and smoking status for the F31I SNP, the homozygous variant genotype (AA) was associated with a significantly increased uterine cancer risk (OR 10.2; 95% CI 2.23–46.5). Individuals with the heterozygous genotype (TA) and a history of tobacco use also exhibited an increased risk for uterine cancer (OR 2.63; 95% CI 1.20–5.76). For the V57I SNP, neither the homozygous (AA) nor the heterozygous (GA) variant genotypes were associated with significantly altered risk for uterine cancer (OR 0.76; 95% CI 0.18–3.25 and OR 0.88; 95% CI 0.52–1.49). Conclusions: Our study demonstrates that STK15 F31I SNP is associated with an increased risk for uterine cancer. Confirmation of this pilot study is needed in a larger case-control population to evaluate this genetic variant with other known risk factors for uterine cancer.

No significant financial relationships to disclose.

An investigator-masked comparison of the efficacy and safety of twice daily applications of calcitriol 3 µg/g ointment vs. calcipotriol 50 µg/g ointment in subjects with mild to moderate chronic plaque-type psoriasis

BACKGROUND

Calcitriol and calcipotriol, two vitamin D derivatives, are available for topical treatment of psoriasis and have been shown to be effective.

AIM

To compare the efficacy and safety of calcitriol 3 microg/g and calcipotriol 50 microg/g.

METHODS

This was a multicentre, randomized, investigator-masked, and parallel comparison in subjects with mild to moderate chronic plaque-type psoriasis receiving either calcitriol or calcipotriol ointment twice daily for 12 weeks. Efficacy evaluations comprised global improvement (on a 4-point scale from 0: no change or worse, to 3: clear or almost clear) assessed by the investigator and by the subject. Efficacy further included the 'dermatological sum score' at each study visit. Safety evaluations included adverse event reporting, cutaneous safety assessed by the investigator and cutaneous discomfort assessment by the subject (both on a 5-point scale from 0: none, to 4: very severe).

RESULTS

A total of 250 subjects of both gender were recruited. At week 12, the LSmean score of global improvement rated by the investigator was 2.27 for calcitriol and 2.22 for calcipotriol. This difference was not statistically significant, with calcitriol demonstrating to be non-inferior to calcipotriol for global improvement. This same parameter was scored by the subject, with a mean of 2.12 for calcitriol and 2.09 for calcipotriol. The percentage of patients with at least marked improvement tended to be in favour of calcitriol (95.7% vs. 85% for calcipotriol). However, differences were not statistically significant. The mean worst score for the cutaneous safety assessment was higher in the calcipotriol group (0.3 vs. 0.1 and 0.4 vs. 0.2, by the investigator and the patient, respectively). These differences were statistically significant in favour of a better safety profile for calcitriol (P=0.0035). Fourteen dermatological and treatment-related adverse events were reported with calcipotriol vs. only five with calcitriol for a total of 22 adverse events reported throughout the study.

CONCLUSION

Calcitriol administered twice daily over a 12-week treatment period demonstrated similar efficacy to calcipotriol, while showing a significantly better safety profile.

Genetic diversity of rhizobia associated with Desmodium species grown in China

AIMS

Desmodia are leguminous plants used as important forage and herbal medicine in China. Little information is available about the nodule bacteria of Desmodium species. To understand the genetic diversity of rhizobia associated with Desmodium species grown in China, isolates from temperate and subtropical regions were obtained and analysed.

METHODS AND RESULTS

A total of 39 rhizobial strains isolated from 9 Desmodium species grown in China were characterized by PCR-based 16S rDNA gene and 16S-23S rDNA intergenic spacer gene restriction fragment length polymorphism (RFLP) and 16S rRNA gene sequencing. The results showed high diversity among rhizobia symbiotic with Desmodium species. Most microsymbionts of Desmodium species belonged to Bradyrhizobium closely related to Bradyrhizobium elkanii, Bradyrhizobium japonicum and Bradyrhizobium yuanmingense. Several small groups or single strain were related to Rhizobium, Sinorhizobium or Mesorhizobium.

CONCLUSIONS

Desmodium species formed nodules with diverse rhizobia in Chinese soils.

SIGNIFICANCE AND IMPACT OF THE STUDY

These results offered the first systematic information about the microsymbionts of desmodia grown in the temperate and subtropical regions of China.

Application of ethyl chloroformate derivatization for gas chromatography-mass spectrometry based metabonomic profiling

A new combined gas chromatography and mass spectrometry (GC-MS) method has been developed suitable for the urine sample treatment in aqueous phase with ethyl chloroformate (ECF) derivatization agents. The method has been extensively optimized and validated over a broad range of different compounds and urine samples. Analysis of test metabolite derivatives, containing spiked standards, or rat urine exhibited acceptable linearity, satisfactory intra-batch precision (repeatability) and stability, relative standard deviations (R.S.D.) less than 10 and 15% within 48 h, respectively. The quantification limits were 150-300 pg on column for most metabolites. Recovery of several representative compounds, at different concentrations, ranged from 70 to 120%, with R.S.D. better than 10% for rat urine. We were able to generally eliminate potentially confounding variables such as medium complexity, different urea concentrations, and/or derivatization procedure variability. Metabonomic profiling of 1,2-dimethylhydrazine (DMH)-induced precancerous colon rat urine using GC-MS with ECF derivatization was performed to evaluate the proposed method. The analytical variation of the method was smaller than the biological variation in the rat urine samples, proving the suitability of the method to analyze differences in the metabonome of a living system with perturbed metabolic network. Thus, the proposed GC-MS analytical method is reliable to analyze a large variety of metabolites and can be used to investigate human pathology including disease onset, progression, and mortality.

Potent antitumor efficacy of XAF1 delivered by conditionally replicative adenovirus vector via caspase-independent apoptosis

XAF1 is a newly identified tumor-suppressor gene that can antagonize XIAP and sensitize cells to other cell death triggers. In this study, we utilized ZD55, a conditionally replicative adenovirus (CRAd) similar to ONYX-015 as the vector to transfer XAF1 into the tumor cells to evaluate its antitumor efficacy in vitro and in vivo. Potent and specific cytopathic effect (CPE) was observed upon infection with ZD55-XAF1 in tumor cell lines. Importantly, ZD55-XAF1 exhibited a superior suppression of tumor growth in an animal model of colorectal carcinoma in nude mice compared with Ad-XAF1 (E1-deleted replication-defective viral) and ONYX-015. Complete eradication of the established tumors was observed in four of eight mice. Our data also showed that infection with ZD55-XAF1 resulted in caspase-independent apoptosis. Although caspase-3, poly(ADP-ribose) polymerase were mildly activated in response to ZD55-XAF1 infection, pretreatment with pan-caspase inhibitor hardly influence its apoptosis-inducing activity. In summary, our study strongly suggested that ZD55-XAF1 could serve as an effective gene-virotherapy strategy and has highly potential against human cancers.

The antitumor activity of TRAIL and IL-24 with replicating oncolytic adenovirus in colorectal cancer

Melanoma differentiation associated gene-7 (Mda-7)/IL-24 was previously cloned into ZD55 (an adenovirus with E1B55 deleted) to form ZD55-IL-24, which had much better antitumor effect than Ad-IL-24. According to its good antitumor properties, ZD55-IL-24 has been used in preclinical studies. But ZD55-IL-24 alone still could not completely eradicate established tumors in all nude mice. It was reported that IL-24 could induce and enhance the activity of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) (a member of tumor necrosis factor (TNF) superfamily). Accordingly, the combined use of ZD55-IL-24 and ZD55-TRAIL was carried out in this study. Treatment with both ZD55-IL-24 and ZD55-TRAIL could induce more significant apoptosis in cancer cells in vitro compared with ZD55-IL-24 or ZD55-TRAIL alone. The combination of the two replicative adenoviruses had better antitumor activity in vivo than that of single oncolytic adenovirus and led to complete eradication of xenograft tumors in all treated mice. Upregulation of TRAIL was observed in tumor cells infected with ZD55-IL-24 and studies of the apoptotic cascade regulators indicate that ZD55-IL-24 could further enhance the activation of apoptosis through the TNF family of death receptors. We demonstrated for the first time the potential therapeutic effect of combined ZD55-IL-24 with ZD55-TRAIL for the targeted therapy of cancer.

Serum deprivation induced apoptosis in macrophage is mediated by autocrine secretion of type I IFNs

Apoptosis can be triggered by different forms of cellular stress. We here show that serum deprivation induces the expression and secretion of type I interferons and results in apoptosis in RAW 264.7 cell in a caspase dependent manner. Administration of either IFN-alpha or IFN-beta antibody partially inhibits apoptosis while the two antibodies used together totally prevents RAW264.7 cell from apoptosis. GM-CSF, but not M-CSF and IL-3, protects serum deprivation induced apoptosis. Inhibition of JAKs also prevents macrophages from apoptosis. Activation of MAPKs is not required for serum deprivation induced apoptosis. Our results are the first to demonstrate that serum deprivation-induced apoptosis acts through autocrine secretion of type I interferons.

Bacterial insertion sequence IS256 as a potential molecular marker to discriminate invasive strains from commensal strains of Staphylococcus epidermidis

The skin commensal Staphylococcus epidermidis has become one of the most important causative agents of nosocomial infections associated with medical devices. Differentiation between invasive S. epidermidis and its commensal counterpart is crucial for clinical decision making. The ica gene locus, which codes for production of polysaccharide intercellular adhesion (PIA), represents a frequently suggested molecular marker for infectivity. Our data demonstrated that production of PIA was not significantly increased among clinical strains, which may explain the controversial results obtained previously on the correlation of ica presence with origin from infection. Therefore, in this study, we attempted to identify novel genes discriminating between invasive and commensal strains based on the comparison of genome sequences. Our results indicated that the bacterial insertion sequence element IS256 occurred significantly more frequently in strains of clinical origin. Importantly, IS256 might thus constitute a molecular marker to discriminate invasive strains from commensal strains of S. epidermidis.