eIf3a mediates malignant biological behaviors in colorectal cancer through the PI3K/AKT signaling pathway

Colorectal cancer (CRC) is among the most common gastrointestinal malignancies worldwide. eIF3a is highly expressed in a variety of cancer types, yet its role in CRC remains unclear. We introduced ectopic eIF3a expression in CRC cells to investigate its relevance to various malignant behaviors. Further, we silenced eIF3a to explore its effect on tumor growth in a nude mouse tumor xenograft model. Finally, the molecular mechanisms through which eIF3a regulates malignancy in CRC cells were explored through bioinformatics analysis combined with the use of a specific PI3K inhibitor (LY294002). eIF3a was highly expressed in the peripheral blood and cancer tissue of CRC patients. Malignancy and tumor growth were significantly inhibited by silencing eIF3a, while overexpression promoted malignant behaviors, with a positive correlation between PI3K/AKT activation and eIF3a expression. Taken together, eIF3a plays an oncogenic role in CRC by regulating PI3K/AKT signaling and is a potential biomarker for CRC diagnosis and prognostic monitoring.

SLC40A1 in iron metabolism, ferroptosis, and disease: A review

Solute carrier family 40 member 1 (SLC40A1) plays an essential role in transporting iron from intracellular to extracellular environments. When SLC40A1 expression is abnormal, cellular iron metabolism becomes dysregulated, resulting in an overload of intracellular iron, which induces cell ferroptosis. Numerous studies have confirmed that ferroptosis is closely associated with the development of many diseases. Here, we review recent findings on SLC40A1 in ferroptosis and its association with various diseases, intending to explore new directions for research on disease pathogenesis and new therapeutic targets for prevention and treatment. This article is categorized under: Cancer > Genetics/Genomics/Epigenetics Metabolic Diseases > Molecular and Cellular Physiology.

Linc-ROR inhibits NK cell-killing activity by promoting RXRA ubiquitination and reducing MICB expression in gastric cancer patients

Linc-ROR plays an important role in gastric cancer (GC) development and progression. This study sought to determine how the aberrant expression of Linc-ROR impacts GC progression and immune evasion, and to identify new targets for GC therapy. GC cells overexpressing Linc-ROR and GSAGS cells were cocultured with NK-92 cells, respectively, and Linc-ROR expression was determined using reverse transcription polymerase chain reaction. Linc-ROR overexpression experiments were used to measure the expression of MICB, a tumor protein that is recognized by natural killer (NK) cells. Bioinformatics analysis identified retinoid X receptor α (RXRA) and YY1 as MICB-specific transcription factors. Cotransfection and ubiquitinated drug experiments found that Linc-ROR promoted the ubiquitination and degradation of RXRA. Linc-ROR was upregulated in GC tissue and high expression was associated with tumor escape from NK-92 cell-mediated immunity. Linc-ROR overexpression inhibited the expression of MICB on the cell surface by degrading RXRA. These findings indicate that Linc-ROR promotes the binding of RXRA and E3 ligase UBE4B, reducing RXRA and MICB expression, and limiting NK cell-killing activity. Linc-ROR is a critical long noncoding RNA with a tumor-promoting function in GC and thus may serve as a potential therapeutic target.

Influence of tumor mycobiome on cancer pathogenesis (Review)

Cancer tissues harbor a large microbiome. There is growing evidence that the tumor microbiome is significantly correlated with the prognosis of cancer patients, but the exact underlying mechanisms have remained elusive. Although the tumor mycobiome is less abundant than the biome of bacteria, it is prevalent in most cancers in humans. The present review describes in detail the impact of the tumor mycobiome on cancer pathogenesis. The tumor mycobiome promotes tumor progression and metastasis by affecting the human immune system, maintaining a pro-inflammatory environment, producing aflatoxins, attenuating cell adhesion mechanisms and fungal-bacterial interactions. Furthermore, the tumor mycobiome likewise has great potential for cancer prevention, diagnosis and treatment.

Experience of management of pediatric upper gastrointestinal perforations: a series of 30 cases

Background

This study aimed to explore the characteristics of pediatric upper gastrointestinal (UGI) perforations, focusing on their diagnosis and management.

Methods

Between January 2013 and December 2021, 30 children with confirmed UGI perforations were enrolled, and their clinical data were analyzed. Two groups were compared according to management options, including open surgical repair (OSR) and laparoscopic/gastroscopic repair (LR).

Results

A total of 30 patients with a median age of 36.0 months (1 day-17 years) were included in the study. There were 19 and 11 patients in the LR and OSR groups, respectively. In the LR group, two patients were treated via exploratory laparoscopy and OSR, and the other patients were managed via gastroscopic repair. Ten and three patients presented the duration from symptom onset to diagnosis within 24 h (p = 0.177) and the number of patients with hemodynamically unstable perforations was 4 and 3 in the LR and OSR groups, respectively. Simple suture or clip closure was performed in 27 patients, and laparoscopically pedicled omental patch repair was performed in two patients. There was no significant difference in operative time and length of hospital stay between the LR and OSR groups. Treatment failed in two patients because of severe sepsis and multiple organ dysfunction syndrome, including one with fungal peritonitis.

Conclusion

Surgery for pediatric UGI perforations should be selected according to the general status of the patient, age of the patient, duration from symptom onset, inflammation, and perforation site and size. Antibiotic administration and surgical closure remain the main strategies for pediatric UGI perforations.

Dysregulation of Long Non-coding RNAs and mRNAs in Plasma of Clear Cell Renal Cell Carcinoma Patients Using Microarray and Bioinformatic Analysis

Objective: The roles of long non-coding RNAs (lncRNAs) in the diagnosis of clear cell renal cell carcinoma (ccRCC) are still not well-defined. We aimed to identify differentially expressed lncRNAs and mRNAs in plasma of ccRCC patients and health controls systematically.

Methods: Expression profile of plasma lncRNAs and mRNAs in ccRCC patients and healthy controls was analyzed based on microarray assay. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway-based approaches were used to investigate biological function and signaling pathways mediated by the differentially expressed mRNAs. SOCS2-AS1 was selected for validation using Real-Time PCR. The differentially expressed lncRNAs and mRNAs were further compared with E-MTAB-1830 datasets using Venn and the NetworkAnalyst website. The GEPIA and ULCAN websites were utilized for the evaluation of the expression level of differentially expressed mRNA and their association with overall survival (OS).

Results: A total of 3,664 differentially expressed lncRNAs were identified in the plasma of ccRCC patients, including 1,511 up-regulated and 2,153 down-regulated lncRNAs (fold change ≥2 and P < 0.05), respectively. There were 2,268 differentially expressed mRNAs, including 932 up-regulated mRNAs and 1,336 down-regulated mRNAs, respectively (fold change ≥2 and P < 0.05). Pathway analysis based on deregulated mRNAs was mainly involved in melanogenesis and Hippo signaling pathway (P < 0.05). In line with the lncRNA microarray findings, the SOCS2-AS1 was down-regulated in ccRCC plasma and tissues, as well as in cell lines. Compared with the E-MTAB-1830 gene expression profiles, we identified 18 lncRNAs and 87 mRNAs differently expressed in both plasma and neoplastic tissues of ccRCC. The expression of 10 mRNAs (EPB41L4B, CCND1, GGT1, CGNL1, CYSLTR1, PLAUR, UGT3A1, PROM2, MUC12, and PCK1) was correlated with the overall survival (OS) rate in ccRCC patients based on the GEPIA and ULCAN websites.

Conclusions: We firstly reported differentially expressed lncRNAs in ccRCC patients and healthy controls systemically. Several differentially expressed lncRNAs and mRNAs were identified, which might serve as diagnostic or prognostic markers. The biological function of these lncRNAs and mRNAs should be further validated. Our study may contribute to the future treatment of ccRCC and provide novel insights into cancer biology.

Nuclear FOXP3 inhibits tumor growth and induced apoptosis in hepatocellular carcinoma by targeting c-Myc

The status of FOXP3 and its isoforms in hepatocellular carcinoma (HCC) is unclear. We aimed to investigate the expression and function of FOXP3 and its isoforms in HCC. The study was performed on 84 HCC patients, HCC cell lines and a mouse tumor model. The levels of FOXP3 and its isoforms were determined by nested PCR, quantitative real-time PCR and immunohistochemistry (IHC) staining. The correlation between their levels and clinicopathologic characteristics was analyzed. The full length of FOXP3 (FOXP3) and exon 3-deleted FOXP3 (FOXP3Δ3) were found to be the major isoforms in HCC. The levels of FOXP3Δ3 mRNA and protein in HCC tumor samples were not significantly different from their adjacent normal tissues. The high expression of FOXP3 protein in HCC patients showed a good overall survival. The overexpression of FOXP3 significantly reduced tumor cell proliferation, migration and invasion. The immunofluorescence result indicated that FOXP3 needed to be translocated into the nucleus to exert its inhibitory function. The luciferase assay demonstrated that FOXP3 could be synergistic with Smad2/3/4 to inhibit the oncogene c-Myc. The co-immunoprecipitation results further revealed that FOXP3 could interact with Smad2/3/4. The chromatin immunoprecipitation (ChIP) assay showed that both FOXP3 and Smad2/3/4 bound the promoter of the c-Myc to inhibit it. The in vivo mouse tumor model study confirmed the inhibitory effect of FOXP3. Collectively, the expression of tumor FOXP3 can inhibit the growth of HCC via suppressing c-Myc directly or indirectly via interacting with Smad2/3/4. Therefore, FOXP3 is a tumor suppressor in HCC.

Correction to: m6A mRNA methylation initiated by METTL3 directly promotes YAP translation and increases YAP activity by regulating the MALAT1-miR-1914-3p-YAP axis to induce NSCLC drug resistance and metastasis

An amendment to this paper has been published and can be accessed via the original article.

Clinical Characteristics of COVID-19 Patients With Digestive Symptoms in Hubei, China: A Descriptive, Cross-Sectional, Multicenter Study

OBJECTIVE

Since the outbreak of Coronavirus Disease 2019 (COVID-19) in December 2019, various digestive symptoms have been frequently reported in patients infected with the virus. In this study, we aimed to further investigate the prevalence and outcomes of COVID-19 patients with digestive symptoms.

METHODS

In this descriptive, cross-sectional, multicenter study, we enrolled confirmed patients with COVID-19 who presented to 3 hospitals from January 18, 2020, to February 28, 2020. All patients were confirmed by real-time polymerase chain reaction and were analyzed for clinical characteristics, laboratory data, and treatment. Data were followed up until March 18, 2020.

RESULTS

In the present study, 204 patients with COVID-19 and full laboratory, imaging, and historical data were analyzed. The average age was 52.9 years (SD ± 16), including 107 men and 97 women. Although most patients presented to the hospital with fever or respiratory symptoms, we found that 103 patients (50.5%) reported a digestive symptom, including lack of appetite (81 [78.6%] cases), diarrhea (35 [34%] cases), vomiting (4 [3.9%] cases), and abdominal pain (2 [1.9%] cases). If lack of appetite is excluded from the analysis (because it is less specific for the gastrointestinal tract), there were 38 total cases (18.6%) where patients presented with a gastrointestinal-specific symptom, including diarrhea, vomiting, or abdominal pain. Patients with digestive symptoms had a significantly longer time from onset to admission than patients without digestive symptoms (9.0 days vs 7.3 days). In 6 cases, there were digestive symptoms, but no respiratory symptoms. As the severity of the disease increased, digestive symptoms became more pronounced. Patients with digestive symptoms had higher mean liver enzyme levels, lower monocyte count, longer prothrombin time, and received more antimicrobial treatment than those without digestive symptoms.

DISCUSSION

We found that digestive symptoms are common in patients with COVID-19. Moreover, these patients have a longer time from onset to admission, evidence of longer coagulation, and higher liver enzyme levels. Clinicians should recognize that digestive symptoms, such as diarrhea, are commonly among the presenting features of COVID-19 and that the index of suspicion may need to be raised earlier in at-risk patients presenting with digestive symptoms. However, further large sample studies are needed to confirm these findings.

Epithelial-mesenchymal transition may be involved in the immune evasion of circulating gastric tumor cells via downregulation of ULBP1

Background

Increasing numbers of studies have demonstrated that circulating tumor cells (CTCs) undergo a phenotypic change termed epithelial‐mesenchymal transition (EMT), and researchers have proposed that EMT might provide CTCs with increased potential to survive in the different microenvironments encountered during metastasis through various ways, such as by increasing cell survival and early colonization. However, the exact role of EMT in CTCs remains unclear.

Methods

In this study, we identified CTCs of 41 patients with gastric cancer using Cyttel‐CTC and im‐FISH (immune‐fluorescence in situ hybridization) methods, and tested the expression of EMT markers and ULBP1 (a major member of the NKG2D—natural killer [NK] group 2 member D—ligand family) on CTCs. Moreover, we investigated the relationship between the expression of EMT markers and ULBP1 on CTCs and gastric cancer cell lines.

Results

Our results showed that the CTCs of gastric cancer patients exhibited three EMT marker subtypes, and that the expression of ULBP1 was significantly lower on mesenchymal phenotypic CTCs (M⁺CTCs) than on epithelial phenotypic CTCs (E⁺CTCs). EMT induced by TGF‐β in vitro produced a similar phenomenon, and we therefore proposed that EMT might be involved in the immune evasion of CTCs from NK cells by altering the expression of ULBP1.

Conclusions

Our study indicated that EMT might play a vital role in the immune invasion of CTCs by regulating the expression of ULBP1 on CTCs. These findings could provide potential strategies for targeting the immune evasion capacity of CTCs.

m6A mRNA methylation initiated by METTL3 directly promotes YAP translation and increases YAP activity by regulating the MALAT1-miR-1914-3p-YAP axis to induce NSCLC drug resistance and metastasis

BACKGROUND

METTL3 is an RNA methyltransferase that mediates m⁶A modification and is implicated in mRNA biogenesis, decay, and translation. However, the biomechanism through which METTL3 regulates MALAT1-miR-1914-3p-YAP axis activity to induce NSCLC drug resistance and metastasis is not very clear.

METHODS

The expression of mRNA was analyzed by qPCR assays. Protein levels were analyzed by western blotting and immunofluorescent staining. Cellular proliferation was detected by CCK8 assays. Cell migration and invasion were analyzed by wound healing and transwell assays, respectively. Promoter activities and gene transcription were analyzed by luciferase reporter assays. Finally, m⁶A modification was analyzed by MeRIP.

RESULTS

METTL3 increased the m⁶A modification of YAP. METTL3, YTHDF3, YTHDF1, and eIF3b directly promoted YAP translation through an interaction with the translation initiation machinery. Moreover, the RNA level of MALAT1 was increased due to a higher level of m⁶A modification mediated by METTL3. Meanwhile, the stability of MALAT1 was increased by METTL3/YTHDF3 complex. Additionally, MALAT1 functions as a competing endogenous RNA that sponges miR-1914-3p to promote the invasion and metastasis of NSCLC via YAP. Furthermore, the reduction of YAP m⁶A modification by METTL3 knockdown inhibits tumor growth and enhances sensitivity to DDP in vivo.

CONCLUSION

Results indicated that the m⁶A mRNA methylation initiated by METTL3 promotes YAP mRNA translation via recruiting YTHDF1/3 and eIF3b to the translation initiation complex and increases YAP mRNA stability through regulating the MALAT1-miR-1914-3p-YAP axis. The increased YAP expression and activity induce NSCLC drug resistance and metastasis.

UBE2C, Directly Targeted by miR-548e-5p, Increases the Cellular Growth and Invasive Abilities of Cancer Cells Interacting with the EMT Marker Protein Zinc Finger E-box Binding Homeobox 1/2 in NSCLC

Background: Recent evidence indicates that UBE2C participates in carcinogenesis by regulating the cell cycle, apoptosis, metastasis, and transcriptional processes. Additionally, miR-548e-5p dysregulation plays a vital role in tumor progression. However, the molecular mechanism via which UBE2C is directly targeted by miR-548-5p, resulting in increase in cellular growth and invasiveness of cancer cells, and its interactions with the epithelial-mesenchymal transition (EMT) marker protein ZEB1/2 in non-small cell lung cancer (NSCLC) is not understood.

Methods: Expression of UBE2C and miR-548e-5p was analyzed using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The protein level of UBE2C and ZEB1/2 was analyzed using western blotting and immunofluorescence staining. Cellular proliferation was detected using the cell counting kit 8 (CCK8) and 3-(4,5-dimethylthiazol-2-Yl)-2,5-diphenyltetrazolium bromide (MTT) assays. Cell migration, invasion, and growth were analyzed using the wound healing and transwell assay. Promoter activity and transcription was analyzed using the luciferase reporter assay. Chromatin immunoprecipitation was used to detect binding of UBE2C to 5′UTR-ZEB1/2.

Results: We observed that 4,5-ubiquitin-conjugating enzyme E2C (UBE2C) expression was higher in NSCLC tissue than in the adjacent normal tissue and was associated with increased cell proliferation and invasion. UBE2C enhanced NSCLC progression and metastasis by affecting the cell cycle and inhibiting apoptosis. We also observed that miR-548e-5p was significantly downregulated in lung cancer tissue specimens, which decreased the expression of its direct substrate, UBE2C. Moreover, miR-548e-5p overexpression and UBE2C under-expression significantly suppressed lung cancer cell proliferation, migration, and invasion. Luciferase reporter and chromatin immunoprecipitation assays indicated that miR-548e-5p directly binds to the 3′-UTR of UBE2C and decreases UBE2C mRNA expression. Furthermore, UBE2C knockdown downregulated the mesenchymal marker vimentin and upregulated the epithelial marker E-cadherin. Bioinformatics assays, coupled with western blotting and luciferase assays, revealed that UBE2C directly binds to the 5′-untranslated region (UTR) of the transcript of the E-cadherin repressor ZEB1/2 and promotes EMT in lung cancer cells.

Conclusion: miR-548e-5p directly binds to the 3′-UTR of UBE2C and decreases UBE2C mRNA expression. UBE2C is an oncogene that promotes EMT in lung cancer cells by directly targeting the 5′-UTR of the transcript encoding the E-cadherin repressor ZEB1/2. miR-548e-5p, UBE2C, and ZEB1/2 constitute the miR-548e-5p-UBE2C-ZEB1/2 signal axis, which enhances cancer cell invasiveness by directly interacting with e EMT marker proteins. We believe that the miR-548e-5p-UBE2C-ZEB1/2 signal axis may be a suitable diagnostic marker and a potential target for lung cancer therapy.

Cancer stem cells in hepatocellular carcinoma: an overview and promising therapeutic strategies

The poor clinical outcome of hepatocellular carcinoma (HCC) patients is ascribed to the resistance of HCC cells to traditional treatments and tumor recurrence after curative therapies. Cancer stem cells (CSCs) have been identified as a small subset of cancer cells which have high capacity for self-renewal, differentiation and tumorigenesis. Recent advances in the field of liver CSCs (LCSCs) have enabled the identification of CSC surface markers and the isolation of CSC subpopulations from HCC cells. Given their central role in cancer initiation, metastasis, recurrence and therapeutic resistance, LCSCs constitute a therapeutic opportunity to achieve cure and prevent relapse of HCC. Thus, it is necessary to develop therapeutic strategies to selectively and efficiently target LCSCs. Small molecular inhibitors targeting the core stemness signaling pathways have been actively pursued and evaluated in preclinical and clinical studies. Other alternative therapeutic strategies include targeting LCSC surface markers, interrupting the CSC microenvironment, and altering the epigenetic state. In this review, we summarize the properties of CSCs in HCC and discuss novel therapeutic strategies that can be used to target LCSCs.

Cytochrome P450 1A2 Metabolizes 17β-Estradiol to Suppress Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) occurs more frequently in men than in women. It is commonly agreed that estrogen plays important roles in suppressing HCC development, however, the underlying mechanism remains largely unknown. Since estrogen is mainly metabolized in liver and its metabolites affect cell proliferation, we sought to investigate if the liver-specific cytochrome P450 1A2 (CYP1A2) mediated the inhibitory effect of estrogen on HCC. In this study, the expression of estrogen-metabolizing enzyme CYP1A2 was determined in HCC tissues and cell lines. Cell proliferation and apoptosis were assessed in cells with or without CYP1A2 overexpression. The levels of 17β-estradiol (E2) and its metabolite 2-methoxyestradiol (2-ME) were determined. A xenograft tumor model in mice was established to confirm the findings. It was found that CYP1A2 expression was greatly repressed in HCC. E2 suppressed HCC cell proliferation and xenograft tumor development by inducing apoptosis. The inhibitory effect was significantly enhanced in cells with CYP1A2 overexpression, which effectively conversed E2 to the cytotoxic 2-ME. E2 in combination with sorafenib showed an additive effect on HCC. The anti-HCC effect of E2 was not associated with estrogen receptors ERα and ERβ as well as tumor suppressor P53 but enhanced by the approved anti-HCC drug sorafenib. In addition, HDAC inhibitors greatly induced CYP1A2 promoter activities in cancer cells, especially liver cancer cells, but not in non-tumorigenic cells. Collectively, CYP1A2 metabolizes E2 to generate the potent anti-tumor agent 2-ME in HCC. The reduction of CYP1A2 significantly disrupts this metabolic pathway, contributing the progression and growth of HCC and the gender disparity of this malignancy.

MiR-26b inhibits hepatocellular carcinoma cell proliferation, migration, and invasion by targeting EphA2

Deregulated microRNAs (miRNAs) have been shown to play important roles in cancer progression as a result of changes in expression of their target genes. In this study, we investigated the expression of miR-16b in eight hepatocellular carcinoma (HCC) cell lines, revealed the roles of miR-26b on hepatocellular carcinoma (HCC) cell proliferation, migration, and invasion, and confirmed that EphA2 is a direct target of miR-26b. The miR-26b expression was decreased and EphA2 expression was evaluated in HCC cell lines. Luciferase assays revealed that miR-26b inhibited EphA2 expression by targeting the 3'-untranslated region of EphA2 mRNA. Overexpression of miR-26b dramatically inhibited the proliferation, invasion, and migration of HCC cells by targeting EphA2. Moreover, miR-26b down-regulated c-Myc and CyclinD1 expression, which was reversed by overexpressed EphA2. Taken together, our data demonstrated the mechanism of miR-26b contributed to HCC progression and implicated that miR-26b's potential in HCC therapy.

Therapeutic efficacy of improved α-fetoprotein promoter-mediated tBid delivered by folate-PEI600-cyclodextrin nanopolymer vector in hepatocellular carcinoma

SNPs in human AFP promoter are associated with serum AFP levels in hepatocellular carcinoma (HCC), suggesting that AFP promoter variants may generate better transcriptional activities while retaining high specificity to AFP-producing cells. We sequenced human AFP promoters, cloned 15 different genotype promoters and tested their reporter activities in AFP-producing and non-producing cells. Among various AFP variant fragments tested, EA4D exhibited the highest reporter activity and thus was selected for the further study. EA4D was fused with tBid and coupled with nano-particle vector (H1) to form pGL3-EA4D-tBid/H1. pGL3-EA4D-tBid/H1 could express a high level of tBid while retain the specificity to AFP-producing cells. In a HCC tumor model, application of pGL3-EA4D-tBid/H1 significantly inhibited the growth of AFP-producing-implanted tumors with minimal side-effects, but had no effect on non-AFP-producing tumors. Furthermore, pGL3-EA4D-tBid/H1 could significantly sensitize HCC cells to sorafenib, an approved anti-HCC agent. Collectively, pGL3-EA4D-tBid/H1, a construct with the AFP promoter EA4D and the novel H1 delivery system, can specifically target and effectively suppress the AFP-producing HCC. This new therapeutic tool shows little toxicity in vitro and in vivo and it should thus be safe for further clinical tests.

[Comparison of laparoscopy-assisted distal gastrectomy with open gastrectomy for advanced gastric cancer]

OBJECTIVE

To evaluate the feasibility, safety and short-term outcomes of laparoscopy-assisted distal gastrectomy for advanced gastric cancer.

METHODS

From January 2007 to June 2008, 135 patients with advanced gastric cancer in the lower or middle stomach were operated, of whom 66 underwent laparoscopy-assisted distal gastrectomy(LADG) with D2 dissection of lymph nodes and 69 received conventional open D2 distal gastrectomy(ODG). Clinical data were recorded and compared between the two groups.

RESULTS

There were no significant differences in age, gender, and TNM staging between LADG and ODG(all P>0.05). All the patients in the LADG group underwent gastrectomy and lymph nodes dissection successfully without conversion to open surgery and no operative deaths occurred. The operative time was significantly longer for the LADG group than for the ODG group[(266.1±55.1) min vs. (223.8±26.8) min)]. The patients in the laparoscopic surgery group had less blood loss[(131.9±88.7) ml vs.(342.3±178.7) ml], earlier recovery of bowel activity[(3.18±1.22) d vs.(4.50±1.59) d], and shorter hospitalization time[(9.20±3.39) d vs. (11.35±4.61) d]. No significant differences were found in the total number of retrieved lymph nodes(25.81±12.53 vs. 27.47±10.28). The morbidity of complications was comparable between two groups(6.1% vs. 15.94%). No mortality and recurrence were observed during a follow-up period of 1-19 months.

CONCLUSIONS

LADG with D2 lymph node dissection is a safe and feasible procedure with adequate lymphadenectomy for advanced gastric cancer.

Laparoscopy-assisted D2 radical distal gastrectomy for advanced gastric cancer

BACKGROUND/AIM

Laparoscopy-assisted surgery has proved useful in the treatment of early gastric cancer, but its use in advanced cancer has rarely been studied. To investigate the efficacy and advantages of laparoscopy-assisted distal gastrectomy (LADG) with D2 dissection of lymph nodes versus conventional open D2 distal gastrectomy (ODG) in advanced gastric cancer.

METHODS

From January 2007 to June 2008, the clinical data of 66 cases of LADG for advanced gastric cancer were compared with that of 69 patients who, during the same period, underwent a conventional open radical distal gastrectomy.

RESULTS

No patient in the LADG group converted to conventional operation with laparotomy. Operative time was significantly longer for the LADG group than for the ODG group (266.05 +/- 55.05 vs. 223.78 +/- 26.79 min). No significant differences were found in the total number of retrieved lymph nodes (25.81 +/- 12.53 vs. 27.47 +/- 10.28) between the two groups. Patients in the LADG group had less blood loss, shorter time of analgesic use, earlier recovery of bowel activity, and shorter postoperative hospitalization time. Complication rates were comparable between the two groups.

CONCLUSIONS

LADG with D2 lymph node dissection is a safe and feasible procedure with adequate lymphadenectomy for the treatment of advanced gastric cancer. A large-scale prospective randomized trial with a longer follow-up period is needed to definitively assess whether LADG is a better alternative than ODG with D2 lymph node dissection.

[Expression and its significance of retinoic acid receptor-beta in colorectal cancer]

OBJECTIVE

To investigate the expression and its significance of retinoic acid receptor-beta (RAR-beta) in colorectal cancer.

METHODS

RAR-beta was detected by immunohistochemistry methods and carcino-embryonic antigen (CEA) was tested by chemiluminescence immunoassay methods in normal tissues, paracancerous tissues and colorectal cancer tissues of 60 patients with colorectal cancer treated from January 2006 to January 2007. Above-mentioned data, together with the clinicopathological data of these 60 patients, were analyzed to figure out the expression and its significance of RAR-beta in colorectal cancer.

RESULTS

The expression rate of RAR-beta in tumor tissues (48%) was significantly lower than those in both normal tissues (87%) and paracancerous tissues (87%) (P < 0.05). And its expression was also significant lower in patients with lymph node metastasis (32%) and patients with advanced cancer (TNM stage III and IV) (29%) than in those without lymph nodes metastasis (60%) and those with early stage cancer (stage I and II) (69%). There was no significant differences among well, mildly and poorly differentiated cancer tissues. The CEA level rose in 20 patients, and its rising rate was remarkably higher in patients with lymph node metastasis (48%) and in patients with advanced cancer (52%) than those without lymph node metastasis (23%) and in early stage(14%).

CONCLUSIONS

The expression of RAR-beta decreases significantly in cancer tissues in patients with colorectal cancer, which may be related to the carcinogenesis of colorectal cancer; and its decreasing degree is correlated negatively with the lymph node metastasis and advanced clinicopathological stage. The expression level of RAR-beta may be a new prognostic indication of patients with colorectal cancer.

[Urinary function after pelvic autonomic nerve preservation of laparoscopic radical resection for rectal cancer]

OBJECTIVE

To evaluate the protection of urinary function after laparoscopic radical resection with pelvic autonomic nerve preservation (PANP) for rectal cancer.

METHODS

Prospectively 139 patients with middle or low rectal cancer receiving surgery during November 2005 to October 2007 were divided into two groups (L-PANP, n = 63; O-PANP, n = 76). The radicalism and safety of L-PANP surgery were analyzed and the effects upon urinary function between the two groups assessed by follow-ups and urodynamic study.

RESULTS

Patients receiving subtypes I and II of L-PANP surgery had less decrease in contraction of bladder than those receiving the same subtype of O-PANP surgery at 10 days post-operation (Z = -2.358, P = 0.018; Z = -2.268, P = 0.033). And no difference was observed in patients receiving subtype III PANP surgery (Z = -1.302, P = 0.237). However, no matter which subtype of PANP surgery, patients of L-PANP group had a better contraction of bladder than those of O-PANP group at 1 month post-operation (P < 0.05). The 1-year survival rate was 98.0% (50/51) in L-PANP group and 96.6% (57/59) in O-PANP group. And no statistical difference was found between them (P = 0.898). Meanwhile, the 1-year relapse rate of pelvic cavity was 3.9% (2/52) in L-PANP group and 5.1% (3/59) in O-PANP group. And no statistical difference was found between them (P = 0.867).

CONCLUSION

As compared with O-PANP surgery, L-PANP surgery shows a superiority in protection of urinary function.

Effect of all-trans retinoic acid on drug sensitivity and expression of survivin in LoVo cells

BACKGROUND

All-trans retinoic acid (ATRA) can influence the tumor cell proliferation cycle, and some chemotherapeutic drugs are cycle specific. In this study, we hypothesize that ATRA can enhance chemotherapeutic drug sensitivity by affecting the cell cycle of tumor cells.

METHODS

The cell cycle of LoVo cells was evaluated using flow cytometry (FCM). Cell viability was analyzed using the MTT assay. The morphologic changes in the treated LoVo cells were measured with acridine orange (AO)/ethidium bromide (EB) staining. Expression of survivin in LoVo cells was analyzed by immunofluorescence assay.

RESULTS

After LoVo cells were treated with ATRA, the G0/G1 ratio of the tumor cells increased and the cell ratio of S- and G2/M-phase decreased. Viability of the cells decreased significantly after combined treatment with ATRA and 5-fluorouracil (5-FU) or mitomycin c (MMC) and was evaluated by fluorescence microscopy. Expression level of survivin in the tumor cells decreased after ATRA combination treatment.

CONCLUSIONS

ATRA enhances drug sensitivity of the LoVo cell line to cell cycle-specific agents and inhibits the expression of survivin in LoVo cells. The combination of ATRA and 5-FU or MMC promoted cell apoptosis, and the mechanism involved in apoptosis may be related to inhibition of survivin gene expression.

Persistent infection of mice by lactate dehydrogenase-elevating virus: effects of immunosuppression on virus replication and antiviral immune responses

Maximum plasma titers (10(9)-10(10) ID50/ml) of lactate dehydrogenase-elevating virus (LDV) in mice are observed one day after infection, but then decrease 4-5 log during the next 5 weeks to attain a persistent steady-state level for the remainder of the life of the animal. The decrease in plasma LDV level during the first 5 weeks after infection and long-term viremia were not affected by lethal X-irradiation of the mice, daily injections of cyclosporin A or depletion of the mice of T cells by treatment with anti-CD4, anti-CD8, or anti-Thy1.2 monoclonal antibodies, although these treatments inhibited the formation of anti-LDV antibodies. LDV viremia was also the same in nu/nu and nu/+ Swiss mice, though the former did not mount an anti-LDV immune response, while the latter did. The appearance of anti-LDV neutralizing antibodies in infected mice 1-2 months after infection or the injection of infected mice with high doses of anti-LDV neutralizing monoclonal antibodies also did not affect the level of LDV viremia. Repeated treatments of infected mice with either cyclophosphamide or dexamethasone caused 1-2 log increases in plasma LDV titers. Although cyclophosphamide treatment prevented the formation of anti-LDV antibodies, dexamethasone caused an increase in plasma LDV levels without affecting anti-LDV antibody formation. We conclude that an anti-LDV immune response does not play a significant role in controlling LDV replication in mice. The data support the view that within 1 day after infection of a mouse, all LDV-permissive macrophages, which appear to be the only cells supporting LDV replication in the mouse, are destroyed as a result of a cytocidal infection by LDV. Subsequently, LDV replication is limited by the rate of generation of new permissive macrophages. The steady-state viremia attained about 5 weeks after infection reflects a balance between LDV replication in permissive macrophages as they arise and LDV inactivation and clearance.