Doxycycline vs Placebo at 12 Weeks in Patients With Mild Thyroid-Associated Ophthalmopathy: A Randomized Clinical Trial

Importance

Mild thyroid-associated ophthalmopathy (TAO) negatively impacts quality of life, yet no clinical guidelines for its treatment are available. Existing evidence supports the use of doxycycline in treating mild TAO.

Objective

To evaluate the short-term (12 weeks) efficacy of doxycycline in treating mild TAO.

Design, Setting, and Participants

In this placebo-controlled multicenter randomized double-masked trial, 148 patients were assessed for eligibility. After exclusions (patients who were pregnant or lactating, had an allergy to tetracyclines, or had uncontrolled systematic diseases), 100 patients with mild TAO (orbital soft tissue affected mildly) at 5 centers in China were enrolled from July 2013 to December 2019 and monitored for 12 weeks.

Interventions

Participants were randomly assigned 1:1 to receive doxycycline (50 mg) or placebo once daily for 12 weeks.

Main Outcomes and Measures

The primary outcome was the rate of improvement at 12 weeks compared with baseline assessed by a composite indicator of eyelid aperture (reduction ≥2 mm), proptosis (reduction ≥2 mm), ocular motility (increase ≥8°), and Graves ophthalmopathy-specific quality-of-life (GO-QOL) scale score (increase ≥6 points). Adverse events were recorded.

Results

A total of 50 participants were assigned to doxycycline and 50 to placebo. The mean (SD) age was 36.7 (9.1) years; 75 participants (75.0%) were female and 100 (100.0%) were Asian. Medication compliance was checked during participant interviews and by counting excess tablets. At week 12, the improvement rate was 38.0% (19 of 50) in the doxycycline group and 16.0% (8 of 50) in the placebo group (difference, 22.0%; 95% CI, 5.0-39.0; P = .01) in the intention-to-treat population. The per-protocol sensitivity analysis showed similar results (39.6% [19 of 48] vs 16.0% [8 of 50]; difference, 23.6%; 95% CI, 6.4-40.8; P = .009). No adverse events other than 1 case of mild gastric acid regurgitation was recorded in either group.

Conclusions and Relevance

The results of this study indicate that oral doxycycline, 50 mg daily, resulted in greater improvement of TAO-related symptoms at 12 weeks compared with placebo in patients with mild TAO. These findings support the consideration of doxycycline for mild TAO but should be tempered by recognizing the relatively short follow-up and the size of the cohort.

Trial Registration

ClinicalTrials.gov Identifier: NCT02203682.

Phylogenetic analysis of porcine circovirus 4 in Henan Province of China: A retrospective study from 2011 to 2021

Porcine circovirus 4 (PCV4), a novel circovirus, was first discovered in April 2019 in Hunan Province of China. At present, PCV4 infection has been detected in China and South Korea. However, until 2019, there was little information about its circulating status and genetic characteristics. To further clarify the origin and prevalence of PCV4, a total of 152 clinical samples collected from 49 different swine farms of 15 cities in Henan Province of China from 2011 to 2021 were tested for the presence of PCV4 by qPCR, and the complete genome of PCV4 strains was amplified from the positive samples and sequenced. Among these samples, 45.39% (69/152) were positive for PCV4 and 86.67% (13/15) of the cities and 67.35% (33/49) of the swine farms were positive for PCV4. The genome sequences of 15 PCV4 strains were obtained, of which two PCV4 strains (HN-ZMD-201212 and HN-XX-201212) were achieved from archival samples in 2012, indicating that PCV4 has been circulating for at least 10 years in Henan Province of China. The phylogenetic analysis showed that 15 PCV4 strains in our study together with PCV4 strain HNU-AHG1-2019 were clustered into an identical but separate evolutionary branch, with genomic identity ranging from 98.2% to 98.8%. Our research further provides significant epidemiological information on PCV4 in China, which will help understand the origin and genetic characteristics of this new virus.

Simultaneous detection and differentiation of porcine circovirus 3 and 4 using a SYBR Green І-based duplex quantitative PCR assay

Porcine circovirus 4 (PCV4) was a novel circovirus identified from diseased pigs in 2019 in Hunan Province, China, and PCV3 and PCV4 co-infection has been reported. In order to detect and differentiate PCV3 and PCV4 simultaneously, the SYBR Green І-based duplex quantitative PCR (qPCR) assay was established in the present study. The two viruses could be easily distinguished by different Tm values: 86.5°C for PCV3 and 79°C for PCV4, while other porcine pathogens did not shown specific melting peaks. The detection limits of this duplex qPCR assay were 51.7 copies/μL for PCV3 and 67.7 copies/μL for PCV4, and both of the intra-assay and inter-assay of the CV analysis of this assay were less than 2.0 %. Sixty-four clinical samples from 22 different swine farms were screened by the duplex qPCR assay. The results showed that the positive detection rate of PCV3 was 37.5 % (24/64) and PCV4 was 34.38 % (22/64), and PCV3 and PCV4 co-infection rate was 17.19 % (11/64). The detection rate of the duplex qPCR assay was higher than that of the conventional PCR assay. The duplex qPCR was of high sensitivity and specificity, being able to provide technical support for clinical detection, differential diagnosis and control of PCV3 and PCV4.

Detection and genetic characteristics of porcine bocavirus in central China

To investigate the epidemic profile and genetic diversity of porcine bocavirus (PBoV), 281 clinical samples, including 236 intestinal tissue samples and 45 fecal samples were collected from diarrheic piglets on 37 different pig farms in central China, and two SYBR Green I-based quantitative PCR assays were developed to detect PBoV1/2 and PBoV3/4/5, respectively. One hundred forty-eight (52.67%) of the 281 clinical samples were positive for PBoV1/2, 117 (41.63%) were positive for PBoV3/4/5, 55 (19.57%) were positive for both PBoV1/2 and PBoV3/4/5, and 86.49% (32/37) of the pig farms were positive for PBoV. Overall, the prevalence of PBoV was 74.73% (210/281) in central China. Subsequently, nearly full-length genomic sequences of two PBoV strains (designated CH/HNZM and PBoV-TY) from two different farms were determined. Phylogenetic analysis demonstrated that the two PBoV strains obtained in this study belonged to the PBoV G2 group and had a close relationship to 10 other PBoV G2 strains but differed genetically from PBoV G1, PBoV G3, and seven other bocaviruses. CH/HNZM and PBoV-TY were closely related to the PBoV strain GD18 (KJ755666), which may be derived from the PBoV strains 0912/2012 (MH558677) and 57AT-HU (KF206160) through recombination. Compared with reference strain ZJD (HM053694)-China, more amino acid variation was found in the NS1 proteins of CH/HNZM and PBoV-TY. These data extend our understanding of the molecular epidemiology and evolution of PBoV.

Characteristics of the spike and ORF3 genes of porcine epidemic diarrhea virus in Henan and Shanxi provinces of China

To investigate the epidemic characteristics of porcine epidemic diarrhea virus (PEDV), 135 clinical samples (including intestinal tissues and feces) were collected from diseased piglets during outbreaks of diarrhea from 2015 to 2019 on farms in Henan and Shanxi provinces of China where swine had been immunized with attenuated PEDV (CV777). A total of 86 clinical samples (86/135, 63.7%) were positive for PEDV by RT-PCR, and subsequently, the complete spike (S) and ORF3 genes of 32 PEDV samples were sequenced. Phylogenetic analysis showed that the 32 PEDV strains obtained in this study belonged to group 2 (pandemic variant strains) and had a close relationship to 17 Chinese strains after 2010, two South Korean strains (KNU-1305 and KNU-1807), three American strains (PC22A-P140.BI, USA/Colorado/2013, and USA/OK10240-6/2017) and a Mexican strain (PEDV/MEX/QRO/02/2017), but differed genetically from a South Korean strain (SM98), a European strain (Br1/87), a Chinese strain (LZC), and a vaccine strain (CV777). G2-a subgroup strains were the dominant pandemic variant strains circulating in Henan and Shanxi provinces of China. Furthermore, a cross-recombination event was identified in the S region of the SX/TY2/2017 strain, and the putative parental strains were the epidemic strains CH/GDGZ/2012 and CH/YZ1/2015, identified in China in 2012 and 2015, respectively. These results provide further information about PEDV evolution, which could improve our understanding of the circulation of PEDV in Henan and Shanxi provinces. This information will also be helpful for developing new strategies for prevention and control of variant strains.

Molecular detection and phylogenetic analysis of Porcine circovirus 4 in Henan and Shanxi Provinces of China

Porcine circovirus 4 (PCV4), a new circovirus with a distinct relationship to other circoviruses, was identified in 2019 in several pigs with severe clinical disease in Hunan Province, China. To investigate the epidemic profile and genetic diversity of the virus, 63 clinical samples were collected from 24 different pig farms in 14 cities in Henan and Shanxi Provinces, China, between February 2018 and December 2019, and the partial Cap gene of PCV4 was amplified by PCR. Among the 63 samples, 16 (25.40%) were positive for PCV4, and 50% (12/24) of the pig farms were positive for PCV4. PCV4 was detected in samples from pigs with different clinical presentations. One PCV4 strain (Henan-LY1-2019) was sequenced in this study, and shared 98.4% genomic nucleotide identity with PCV4 strain HNU-AHG1-2019 (accession no. MK986820) detected on a pig farm in Hunan Province in 2019. A phylogenetic analysis based on the genomes of Henan-LY1-2019 and 31 reference strains showed that the Henan-LY1-2019 strain together with PCV4 strain HNU-AHG1-2019 was grouped in a relatively independent sub-branch, and separated from other viruses in the genus Circovirus. The results of this study extend our understanding of the molecular epidemiology of PCV4.

Development of a duplex SYBR GreenⅠ based real-time PCR assay for detection of porcine epidemic diarrhea virus and porcine bocavirus3/4/5

The duplex real-time PCR assay based on SYBR Green І was developed for detection of porcine epidemic diarrhea virus (PEDV) and porcine bocavirus (PBoV) 3/4/5 genotypes simultaneously. Two pairs of specific primers were designed targeting the N gene sequence of PEDV and VP1 gene sequence of PBoV3/4/5. PEDV and PBoV3/4/5 could be distinguished by their different melting temperatures (Tm) in one sample. The Tm value of PEDV was 83.5 °C, and the Tm value of PBoV3/4/5 was 78.5 °C, while other swine pathogens showed no specific melting peaks. The detection limits of this assay were 10 copies/μL for both PEDV and PBoV3/4/5. A total of sixty-three intestinal tissue samples were collected from piglets suffering from diarrhea, and the viral nucleic acids detected and identified by the real-time PCR assay and conventional PCR assay. The duplex real-time PCR detection results showed that the prevalence of PEDV and PBoV3/4/5 was 85.7% and 46%, respectively, and the co-infection rate of the two viruses was 28.6%. These results indicated that this duplex real-time PCR assay was a sensitive, specific and reproducible method for differentiating PEDV and PBoV3/4/5 or their co-infection.

Simultaneous detection of classical swine fever virus and porcine circovirus 3 by SYBR green I-based duplex real-time fluorescence quantitative PCR

In the present study, the SYBR green I-based duplex quantitative polymerase chain reaction (qPCR) was developed for simultaneous detection of classical swine fever virus (CSFV) and porcine circovirus 3 (PCV3). The assay was used to detect both CSFV and PCV3 in one sample by their distinct melting temperatures (melting peaks at 87°C for CSFV and 81.5 °C for PCV3), and no specific fluorescence signals were detected for other non-targeted porcine pathogens. The assay had a high degree of linearity (R² > 0.998) with the detection limits of 23 copies/μL for CSFV and 36 copies/μL for PCV3, and exhibited high repeatability and reproducibility with a low coefficient of variation below 2.0% in both intra- and inter-assay. In this study, 130 clinical samples collected from sick pigs in the field were tested by this assay with the positive rates of 9.23% (12/130) for CSFV and 21.54% (28/130) for PCV3 respectively, and the positive rate of CSFV and PCV3 co-infection was 6.92% (9/130). Our results showed that the developed method was a reliable diagnostic tool to monitor and survey CSFV, PCV3 and CSFV/PCV3 co-infection in the field.

Development of a TB green II-based duplex real-time fluorescence quantitative PCR assay for the simultaneous detection of porcine circovirus 2 and 3

Porcine circovirus 3 (PCV3), as a newly emerged circovirus, is widely distributed in pig populations worldwide. Co-infection of PCV2 and PCV3 has been reported frequently in clinical samples. In the present study, a TB Green II-based duplex real-time polymerase chain reaction (qPCR) was developed to rapidly and differentially detect PCV2 and PCV3. The assay specifically detected PCV2 and PCV3, with no fluorescence signals being detected for other non-targeted pig pathogens. The duplex qPCR showed a high degree of linearity (R² > 0.998), and its limits of detection were 10 and 78 copies/μL for PCV2 and PCV3, respectively. The duplex qPCR could detect and differentiate PCV2 (melting peaks at 85.5 °C) and PCV3 (melting peaks at 82.5 °C), and showed high repeatability and reproducibility, with intra- and inter-assay coefficients of variation of less than 2.0%. Fifty-six tissue samples from 18 pig farms were used to evaluate the duplex qPCR method. The results revealed infection rates of 66.07% (37/56) and 39.28% (22/56) for PCV2 and PCV3, respectively. The PCV2 + PCV3 co-infection rate was 39.28% (22/56). The developed method could be used as an efficient molecular biology tool for epidemiological investigations of PCV2 and PCV3.

STAT3 signaling drives EZH2 transcriptional activation and mediates poor prognosis in gastric cancer

BACKGROUND

STAT3 signaling plays the pivotal role in tumorigenesis through EZH2 epigenetic modification, which enhanced STAT3 activity by increased tyrosine phosphorylation of STAT3. Here, another possible feedback mechanism and clinical significance of EZH2 and STAT3 were investigated in gastric cancer (GC).

METHODS

STAT3, p-STAT3 (Tyr 705) and EZH2 expression were examined in 63 GC specimens with matched normal tissues by IHC staining. EZH2 and STAT3 were also identified in five GC cell lines using RT-PCR and western blot analyses. p-STAT3 protein was detected by western blotting. In order to investigate whether EZH2 expression was directly regulated by STAT3, EZH2 expression was further detected using siRNA for STAT3 or IL-6 stimulation, with dual luciferase reporter analyses, electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) assays. The clinical significance of STAT3, p-STAT3 and EZH2 expression was evaluated by multi-factor COX regression and Kaplan-Meier analyses.

RESULTS

Hyper-activation of STAT3, p-STAT3 and EZH2 expression were observed in GC cells and tissues. STAT3 signaling was correlated with EZH2 expression in GC (R = 0.373, P = 0.003), which was consistent with our data showing that STAT3 as the transcriptional factor enhanced EZH2 transcriptional activity by binding the relative promoter region (-214 ~ -206). STAT3 was an independent signature for poor survival (P = 0.002). Patients with STAT3⁺/EZH2⁺ or p-STAT3⁺/EZH2⁺ had a worse outcome than others (P < 0.001); Besides, high levels of STAT3 and EZH2 was associated with advanced TNM staging (P = 0.017). Moreover, treatment with a combination of siSTAT3 and EZH2-specific inhibitor, 3-deazaneplanocin A (DZNEP), increased the apoptotic ratio of cells. It is benefit for targeting STAT3-EZH2 interplay in GC treatment.

CONCLUSIONS

Our results indicate that STAT3 status mediated EZH2 upregulation, associated with advanced TNM stage and poor prognosis, suggesting that combination with knockdown of STAT3 and EZH2 inhibitor might be a novel therapy in GC treatment. Collectively, STAT3, p-STAT3 and EZH2 expression were provided for the precision medicine in GC patients.

GKN1 inhibits cell invasion in gastric cancer by inactivating the NF-kappaB pathway

Metastasis is a relatively early event and a major cause of death in gastric cancer (GC) patients. Gastrokine 1 (GKN1) is a stomach-specific protein that is normally expressed in gastric mucosa but not in primary tumors or cell lines. We and others have demonstrated that GKN1 inhibits cell growth; however, its role in metastasis is not clear. In this study, we explored the role of GKN1 in cell invasion. Immunohistochemistry (IHC) was used to measure the expression of GKN1 in precancerous lesions and in GCs. The cell invasion assay was employed to examine the effect of GKN1 on cell invasion. The molecular mechanism of GKN1 in inhibiting GC cell invasion in vitro was explored by western blotting. We noted a gradual decrease in GKN1 expression from normal mucosa to dysplastic gastric tissue to GC, and that low GKN1 expression was associated with metastasis (P=0.003). We showed that GKN1 inhibits cell invasion by downregulating MMP2 expression through the NF-κB pathway. These results provide molecular evidence that GKN1 inhibits metastasis in GC cells, and indicate that GKN1 is a potential novel therapeutic target for gastric cancer.

Overexpression of p42.3 promotes cell growth and tumorigenicity in hepatocellular carcinoma

AIM: To investigate the association of p42.3 expression with clinicopathological characteristics and the biological function of p42.3 in human hepatocellular carcinoma (HCC).

METHODS: We used reverse transcription-polymerase chain reaction (RT-PCR), quantitative real-time RT-PCR and western blotting to detect p42.3 mRNA and protein expression in hepatic cell lines. We examined primary HCC samples and matched adjacent normal tissue by immunohistochemistry to investigate the correlation between p42.3 expression and clinicopathological features. HepG2 cells were transfected with a pIRES2-EGFP-p42.3 expression vector to examine the function of the p42.3 gene. Transfected cells were analyzed for their viability and malignant transformation abilities by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, colony formation assay, and tumorigenicity assay in nude mice.

RESULTS: p42.3 is differentially expressed in primary HCC tumors and cell lines. Approximately 69.6% (96/138) of cells were p42.3-positive in hepatic tumor tissues, while 30.7% (35/114) were p42.3-positive in tumor-adjacent normal tissues. Clinicopathological characteristics of the HCC specimens revealed a significant correlation between p42.3 expression and tumor differentiation (P = 0.031). However, p42.3 positivity was not related to tumor tumor-node-metastasis classification, hepatitis B virus status, or hepatoma type. Regarding p42.3 overexpression in stably transfected HepG2 cells, we discovered significant enhancement of cancer cell growth and colony formation in vitro, and significantly enhanced tumorigenicity in nude mice. Western blot analysis of cell cycle proteins revealed that enhanced p42.3 levels promote upregulation of proliferating cell nuclear antigen, cyclin B1 and mitotic arrest deficient 2.

CONCLUSION: p42.3 promotes tumorigenicity and tumor growth in HCC and may be a potential target for future clinical cancer therapeutics.

MAWBP and MAWD inhibit proliferation and invasion in gastric cancer

AIM: To investigate role of putative mitogen-activated protein kinase activator with WD40 repeats (MAWD)/MAWD binding protein (MAWBP) in gastric cancer (GC).

METHODS: MAWBP and MAWD mRNA expression level was examined by real-time reverse transcriptase-polymerase chain reaction and semi-quantitative polymerase chain reaction in six GC cell lines. Western blotting was used to examine the protein expression levels. We developed GC cells that stably overexpressed MAWBP and MAWD, and downregulated expression by RNA interference assay. Proliferation and migration of these GC cells were analyzed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl tetrazolium bromide (MTT), soft agar, tumorigenicity, migration and transwell assays. The effect of expression of MAWBP and MAWD on transforming growth factor (TGF)-β1-induced epithelial-mesenchymal transition (EMT) was examined by transfection of MAWBP and MAWD into GC cells. We detected the levels of EMT markers E-cadherin, N-cadherin and Snail in GC cells overexpressing MAWBP and MAWD by Western blotting. The effect of MAWBP and MAWD on TGF-β signal was detected by analysis of phosphorylation level and nuclear translocation of Smad3 using Western blotting and immunofluorescence.

RESULTS: Among the GC cell lines, expression of endogenous MAWBP and MAWD was lowest in SGC7901 cells and highest in BGC823 cells. MAWBP and MAWD were stably overexpressed in SGC7901 cells and knocked down in BGC823 cells. MAWBP and MAWD inhibited GC cell proliferation in vitro and in vivo. MTT assay showed that overexpression of MAWBP and MAWD suppressed growth of SGC7901 cells (P < 0.001), while knockdown of these genes promoted growth of BGC823 cells (P < 0.001). Soft agar colony formation experiments showed that overexpression of MAWBP and MAWD alone or together reduced colony formation compared with vector group in SGC7901 (86.25 ± 8.43, 12.75 ± 4.49, 30 ± 6.41 vs 336.75 ± 22.55, P < 0.001), and knocked-down MAWBP and MAWD demonstrated opposite effects (131.25 ± 16.54, 88.75 ± 11.12, 341.75 ± 22.23 vs 30.25 ± 8.07, P < 0.001). Tumorigenicity experiments revealed that overexpressed MAWBP and MAWD inhibited GC cell proliferation in vivo (P < 0.001). MAWBP and MAWD also inhibited GC cell invasion. Transwell assay showed that the number of traverse cells of MAWBP, MAWD and coexpression group were more than that in vector group (84 ± 16.57, 98.33 ± 9.8, 29 ± 16.39 vs 298 ± 11.86, P < 0.001). Coexpression of MAWBP and MAWD significantly decreased the cells traversing the matrix membrane. Conversely, knocked-down MAWBP and MAWD correspondingly promoted invasion of GC cells (100.67 ± 14.57, 72.66 ± 8.51, 330.67 ± 20.55 vs 27 ± 11.53, P < 0.001). More importantly, coexpression of MAWBP and MAWD promoted EMT. Cells that coexpressed MAWBP and MAWD displayed a pebble-like shape and tight cell-cell adhesion, while vector cells showed a classical mesenchymal phenotype. Western blotting showed that expression of E-cadherin was increased, and expression of N-cadherin and Snail was decreased when cells coexpressed MAWBP and MAWD and were treated with TGF-β1. Nuclear translocation of p-Smad3 was reduced by attenuating its phosphorylation.

CONCLUSION: Coexpression of MAWBP and MAWD inhibited EMT, and EMT-aided malignant cell progression was suppressed.

Differential expression of Rab27A/B correlates with clinical outcome in hepatocellular carcinoma

AIM: To investigate the association of Rab27A and Rab27B expression with clinicopathological characteristics and prognosis of hepatocellular carcinoma (HCC).

METHODS: We used reverse transcription polymerase chain reaction (RT-PCR), real-time PCR, and Western blotting to detect Rab27A and Rab27B mRNA and protein expression in 5 human HCC lines and the immortalized hepatic HL-7702 cell line. We further examined 148 primary HCC samples matched with adjacent normal tissue and 80 non-HCC specimens by immunohistochemistry to evaluate the correlation of Rab27A and Rab27B expression with clinicopathological features and prognosis.

RESULTS: Our data showed that Rab27A and Rab27B were differentially expressed in cell lines and primary HCC tumors. Rab27A mRNA and protein were detected in 67% (4/6) of human cell lines and 80% (4/5) of HCC cell lines, while Rab27B was found in 50% (3/6) of human lines and 40% (2/5) of HCC lines. Rab27A expression was higher in primary HCC (46.2%, 66/143) than in matched adjacent tissue (24.3%, 33/136, P < 0.001), whereas immunopositivity for Rab27B was lower in primary HCC (57.4%, 81/141) than in matched adjacent tissue (87.5%, 119/136, P < 0.001). Analysis of clinicopathological characteristics of 148 HCC specimens revealed significant correlations between Rab27A and Rab27B expression and tumor tumor-node-metastasis (TNM) classification (P = 0.046 and P = 0.027, respectively), and between strong Rab27A expression and tumor differentiation grade (P = 0.008). Survival analyses revealed that patients with Rab27A⁺ or Rab27B⁺ tumors had significantly reduced overall survival compared with that of patients with Rab27A^- or Rab27B^- tumors (P = 0.015 and P = 0.005, respectively). Risk analyses revealed that Rab27B⁺ and TNM III-IV were independent poor prognosis factors associated with a 3.36- and 3.37- fold higher relative risk of death, respectively.

CONCLUSION: Rab27A and Rab27B expression were closely correlated with tumor progression and can be valuable prognostic indicators for HCC patients.

Expression status of S100A14 and S100A4 correlates with metastatic potential and clinical outcome in colorectal cancer after surgery

To investigate whether S100A14 and S100A4 expression correlates with metastatic potential and prognosis in colorectal cancer (CRC), we firstly used RT-PCR analysis to detect mRNA expression of S100A14 and S100A4 in 40 pairs of fresh tumor samples matched with adjacent normal tissues. We then evaluated the clinical significance of our findings with immunohistochemistry on 115 samples of formalin-fixed and paraffin-embedded tumors on tissue microarrays. Typically, we identified decreased S100A14 mRNA levels (52.5%, 21/40), and increased S100A4 mRNA levels (70.0%, 28/40) in primary CRC samples. In addition, down-regulated or absent S100A14 expression was detected in 56.5% of samples (65/115) and was correlated with poor differentiation (P=0.010). In contrast, overexpressed S100A4 was detected in 57.4% of samples (66/115) and was associated with lymph node metastasis (P=0.001). Simultaneous S100A14 low-expression and S100A4 high-expression was correlated with high CRC metastatic potential (P<0.001). Taken together, the signature derived from the combined expression status of S100A14 and S100A4 could be a valuable prognostic indicator in CRC.

Antisense targeting protein kinase C alpha and beta1 inhibits gastric carcinogenesis

Protein kinase C (PKC) family, which functions through serine/threonine kinase activity, is involved in signal transduction pathways necessary for cell proliferation, differentiation, and apoptosis. Its critical role in neoplastic transformation and tumor invasion renders PKC a potential target for anticancer therapy. In this study, we investigated the effect of targeting individual PKCs on gastric carcinogenesis. We established gastric cancer cell lines stably expressing antisense PKCalpha, PKCbeta1, and PKCbeta2 cDNA. These stable transfectants were characterized by cell morphology, cell growth, apoptosis, and tumorigenicity in vitro and in vivo. PKCalpha-AS and PKCbeta1-AS transfectants showed a different morphology with flattened, long processes and decreased nuclear:cytoplasmic ratio compared with the control cells. Cell growth was markedly inhibited in PKCalpha-AS and PKCbeta1-AS transfectants. PKCalpha-AS and PKCbeta1-AS cells were more responsive to mitomycin C- or 5-fluorouracil-induced apoptosis. However, antisense targeting of PKCbeta2 did not have any significant effect on cell morphology, cell growth, or apoptosis. Furthermore, antisense inhibition of PKCalpha and PKCbeta1 markedly suppressed colony-forming efficiency in soft agar and in nude mice xenografts. Inhibition of PKCalpha or PKCbeta1 significantly suppressed transcriptional and DNA binding activity of activator protein in gastric cancer cells, suggesting that PKCalpha or PKCbeta1 exerts their effects on cell growth through regulation of activator protein activity. These data provide evidence that targeting PKCalpha and PKCbeta1 by antisense method is a promising therapy for gastric cancer.

Alteration of the ATM gene occurs in gastric cancer cell lines and primary tumors associated with cellular response to DNA damage

Ataxia telangiectasia mutated (ATM) is the gene mutated in the genetic disorder ataxia telangiectasia (AT), the symptoms of which include sensitivity to radiation and an increased risk of cancer. ATM is a kinase involved in activating the appropriate damage-response pathway, leading to either cell-cycle arrest or apoptosis, and is therefore a key checkpoint molecule in regulating cell-cycle response to DNA damage and responsible for maintenance of genome integrity. However, little is known about the association of ATM mutations with human gastric cancer (HGC). In order to determine the mutation and mRNA expression changes of the ATM gene in HGC, we performed analyses by denaturing high-performance liquid chromatography (DHPLC), DNA sequencing and RT-PCR technique on 13 human gastric tumor cell lines and 30 cases of fresh tumor specimens matched normal tissue. We compared the potential effect of the ATM gene mutation and cell behavior including cell-cycle arrest and induction of apoptosis in the tumor cell lines MGC803 and BGC823 with and without ionizing radiation (IR) exposure. Our data show that frequent variations were observed at 10 exons and 2 cDNA fragments which covered 8 other exons of the ATM gene as 5 out of 13 on the cell lines (38.5%) and 2 out of 30 cases in the tissue specimens (6.7%). All point mutations were confirmed as base substitutions (5982T-C; 6620A-G; 8684G-G/A; 9389C-G) and deletions (1079delC) by use of DNA sequencing. Among the mutations, one was reported previously in breast cancer, the other five have not yet been reported. The expression of ATM was significantly lower in five cell lines (MGC803; MKN45; SGC7901; GES and SUN-1) than in two others (BGC823 and RF48). G2/M cell-cycle arrest and apoptosis were observed in ATM-deficient MGC803 cells challenged with IR. A transient up-regulation of p53 occurred 1h post-IR in BGC823 cells but not in MGC803 cells. Our findings suggest that ATM mutations might be a pathogenic factor for an increased risk of gastric cancer, and the dysfunction of ATM may lead to a hypersensitivity to ionizing radiation in gastric cancer cells, possibly by a p53-dependent pathway.

[Mutations of fragile histidine triad gene in Peutz-Jeghers syndrome and canceration]

BACKGROUND & OBJECTIVE

Peutz-Jeghers syndrome (PJS) is an autosomal dominantly inherited disease. Fragile histidine triad (FHIT) gene is an important tumor suppressor gene at the fragile sites region of 3p14. The authors' previous study suggested that PJS patients might have a susceptible gene at the region of 3p14.2. This study was designed to reveal the relationship between the variant of FHIT gene in PJS and its canceration.

METHOD

Mutations of FHIT gene in 15 PJS patients and 20 unaffected members in 6 PJS families were determined using denaturing high-performance liquid chromatography (DHPLC), polymerase chain reaction-single strand conformation polymorphism(PCR-SSCP) and DNA sequencing techniques.

RESULTS

A non-sense mutation and a frame-shift mutation were identified at codon 54(GAA to TAA) (exon 6) which led to the change of the amino acid from glutamic acid (Glu) to stop codon, and a guanine insertion at codon 62 in exon 6 resulting in a premature stop codon TGA at codon 111 in one PJS patient. A homozygous deletion and a synonymous mutation were detected in exon 8. The homozygous deletion of exon 8 in FHIT gene was found in two polyps tissues and two cancerous tissues. And in 3 sporadic cases, the patients and their mothers have the same bands of SSCP and the same elution profiles of DHPLC when exon 8 was amplified. The DNA sequencing result showed that a synonymous mutation (polymorphism) occurred at codon 98 [CAT (H)-->CAC (H)], this mutation resulted in no change of amino acid. In addition, one base substitute from A to G mutation at 5'end, +42 nucleotide in intron 6 of FHIT gene was detected in seven patients and two unaffected members.

CONCLUSION

PJS patients have low frequency point mutation of FHIT gene and their cancerous tissues had homozygous deletions in FHIT gene. This study indicated that the mutations and deletions of FHIT gene in PJS may play a role in the development of PJS and their cancerations.

Construction of cDNA representational difference analysis based on two cDNA libraries and identification of garlic inducible expression genes in human gastric cancer cells

AIM: To elucidate molecular mechanism of chemopreventive efficacies of garlic against human gastric cancer (HGC).

METHODS: HGC cell line BGC823 was treated with Allitridi (a kind of garlic extract) and Allitridi-treated and parental BGC823 cDNA libraries were constructed respectively by using λZAP II vector. cDNA Representational Difference Analysis (cDNA RDA) was performed using BamH I cutting-site and abundant cDNA messages provided by the libraries. Northern blot analysis was applied to identify the obtained difference products.

RESULTS: Two specific cDNA fragments were obtained and characterized to be derived from homo sapiens folate receptorα (FRα) gene and calcyclin gene respectively. Northern blot results showed a 4-fold increase in FRα gene expression level and 9-fold increase in calcyclin mRNA level in BGC823 cells after Allitridi treatment for 72 h.

CONCLUSION: The method of cDNA RDA based on cDNA libraries combines the high specificity of cDNA RDA with abundant cDNA messages in cDNA library; this expands the application of cDNA library and increases the specificity of cDNA RDA. Up-regulation of FRα gene and calcyclin gene expressions induced by Allitridi provide valuable molecular evidence for the efficacy garlic in treating HGC as well as other diseases.