Role of the vitamin C in diethylnitrosamine-induced esophageal cancer in Wistar rats

Sorafenib Alleviates Inflammatory Signaling of Tumor Microenvironment in Precancerous Lung Injuries

According to population-based studies, lung cancer is the prominent reason for cancer-related mortality worldwide in males and is also rising in females at an alarming rate. Sorafenib (SOR), which is approved for the treatment of hepatocellular carcinoma and renal cell carcinoma, is a multitargeted protein kinase inhibitor. Additionally, SOR is the subject of interest for preclinical and clinical trials in lung cancer. This study was designed to assess in vivo the possible effects of sorafenib (SOR) in diethylnitrosamine (DEN)-induced lung carcinogenesis and examine its probable mechanisms of action. A total of 30 adult male rats were divided into three groups (1) control, (2) DEN, and (3) DEN + SOR. The chemical induction of lung carcinogenesis was performed by injection of DEN intraperitoneally at 150 mg/kg once a week for two weeks. The DEN-administered rats were co-treated with SOR of 10 mg/kg by oral gavage for 42 alternate days. Serum and lung tissue samples were analyzed to determine SRY-box transcription factor 2 (SOX-2) levels. The tumor necrosis factor alpha (TNF-α) and interleukin-1 beta (IL-1β) levels were measured in lung tissue supernatants. Lung sections were analyzed for cyclooxygenase-2 (COX-2) and c-Jun N-terminal kinase (JNK) histopathologically. In addition, cyclooxygenase-2 (COX-2) and c-Jun N-terminal kinase (JNK) were analyzed by immunohistochemistry and immunofluorescence methods, respectively. SOR reduced the level of SOX-2 that maintenance of cancer stemness and tumorigenicity, and TNF-α and IL-1β levels. Histopathological analysis demonstrated widespread inflammatory cell infiltration, disorganized alveolar structure, hyperemia in the vessels, and thickened alveolar walls in DEN-induced rats. The damage was markedly reduced upon SOR treatment. Further, immunohistochemical and immunofluorescence analysis also revealed increased expression of COX-2 and JNK expression in DEN-intoxicated rats. However, SOR treatment alleviated the expression of these inflammatory markers in DEN-induced lung carcinogenesis. These findings suggested that SOR inhibits DEN-induced lung precancerous lesions through decreased inflammation with concomitant in reduced SOX-2 levels, which enables the maintenance of cancer stem cell properties.

Neoadjuvant chemoradiotherapy and surgery compared with surgery alone in squamous cell carcinoma of the esophagus

CONTEXT

Despite progress in recent years in methods of diagnosis and surgical treatment of esophageal cancer, there is still controversy about the benefits from neoadjuvant chemoradiotherapy.

OBJECTIVE

To analise the survival of patients submitted to esophagectomy for squamous cell carcinoma of the esophagus with or without neoadjuvant chemoradiotherapy.

METHOD

A retrospective, non-randomized study conducted using the medical charts of patients operated for squamous cell carcinoma of the esophagus at the School of Medical Sciences, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil between 1979 and 2006. The Kaplan-Meier analysis was used to calculate survival curves and the log-rank test to compare data in each group. The significance level was settled as 5%.

RESULTS

A total of 123 patients were evaluated in this study, divided into three groups: I-26 (21.2%) patients submitted to esophagectomy alone; II-81 (65.8%) patients submitted to neoadjuvant radiotherapy plus esophagectomy and III-16 (13%) patients submitted to neoadjuvant chemoradiotherapy plus esophagectomy. A statistically significant survival was recorded between the groups (log rank=6.007; P=0.05), survival being greatest in the group submitted to neoadjuvant chemoradiotherapy, followed by the group submitted to neoadjuvant radiotherapy compared to the group submitted to esophagectomy alone as the initial treatment of choice.

CONCLUSION

Radiotherapy and chemotherapy neoadjuvants in patients with squamous cell carcinoma of the esophagus offers benefits and increases survival.

Red and processed meat consumption and the risk of esophageal and gastric cancer subtypes in The Netherlands Cohort Study

BACKGROUND

Prospective data on red and processed meat in relation to risk of subtypes of esophageal and gastric cancer are scarce. We present analyses of association between red and processed meat and the risk of esophageal and gastric cancer subtypes within The Netherlands Cohort Study on Diet and Cancer.

DESIGN

120 852 individuals aged 55-69 years were recruited in 1986, and meat intake was assessed using a 150-item food frequency questionnaire. After 16.3 years of follow-up, 107 esophageal squamous cell carcinomas, 145 esophageal adenocarcinomas, 163 gastric cardia adenocarcinomas, 489 gastric non-cardia adenocarcinomas, and 3923 subcohort members were included in a case-cohort analysis.

RESULTS

Processed as well as red meat intake was positively associated with esophageal squamous cell carcinoma in men. Hazard ratios for highest versus lowest quintile of processed and red meat were 3.47 [95% confidence intervals (CI): 1.21-9.94; P for trend: 0.04] and 2.66 (95% CI: 0.94-7.48; P for trend: 0.06), respectively. No association was seen for adenocarcinomas or gastric cancer subtypes or for any of the four subtypes among women.

CONCLUSION

Our findings suggest that red and processed meat consumption is associated with increased risk of esophageal squamous cell carcinoma in men but not with cancers of other esophageal and gastric subtypes.

The jejunoileal bypass provokes morphological changes in the large intestine? An experimental study in rats

PURPOSE

To analyse histopathological alterations characterized by the mitotic index in the mucosa of the large intestine in Wistar rats submitted to jejunoileal bypass operation after continued administration of sodium nitrite and vitamin C to different groups.

METHODS

Eighty male Wistar rats were employed and separated into 12 groups. In the control group (20 rats): five animals ingested only water; five animals received vitamin C; five animals received sodium nitrite and five received sodium nitrite + vitamin C. In the sham group (20 rats), the animals were anesthetized and underwent midline laparotomy and only intestinal manipulation was performed: five animals ingested only water; five animals received vitamin C; five animals received sodium nitrite and five received sodium nitrite + vitamin C. In the operated group 40 rats underwent a jejunoileal bypass surgery: ten animals ingested only water; ten animals received vitamin C; ten animals received sodium nitrite and ten received sodium nitrite + vitamin C. The mean weight of the animals was measured weekly. The large intestine was subdivided into cecum (S1), ascending colon (S(2)), transverse colon (S(3)), descending colon (S(4)) and rectum (S(5)) for histopathological analysis and mitotic counts. The statistical analysis was used to compare the mitotic indices. The level of significance was 5%.

RESULTS

The mean of all the segments indicates that the sodium nitrite+vitamin C group obtained the lowest mitotic index compared to the other treatments in the control group. The segments S(1) and S(2) showed a statistical difference with the vitamin C treatment: a higher mitotic index and better preservation of the mucosa in the operated group. In the sham group the main statistical difference occurred only in the sodium nitrite+vitamin C group between the means of the segments.

CONCLUSIONS

The comparison of all the colonic segments of the various groups revealed a lower mitotic index in the animals treated with sodium nitrite+vitamin C. In addition, it was found that vitamin C did not present a statistically significant inhibiting effect on the preservation of the mucosa and the mitotic index.

The roles of melatonin and vitamin E plus selenium in prevention of oxidative stress induced by naloxone-precipitated withdrawal in heroin-addicted rats

The therapeutic effects of melatonin or vitamin E plus Se (vE + Se) on the restrain of the heroin withdrawal-induced oxidative stress were studied. For this, rats were divided into ten groups. The rats were injected by fixed or variable doses of heroin for 16 consecutive days, and naloxone was given 1 h after the last heroin injection. One hour after naloxone administration, some groups were treated with melatonin or vE + Se. After 1 h this, blood samples were taken, and the levels of malondialdehyde (MDA) and reduced glutathione (GSH) in whole blood, ascorbic acid, α-tocopherol, retinol, β-carotene, nitrite, nitrate, and ceruloplasmin levels in the serum were measured. Our findings showed that, naloxone administration precipitated the heroin withdrawal. This also increased the level of MDA and decreased the levels of GSH in blood. Melatonin or vE + Se administration prevented the rise in MDA levels and increased the GSH levels. On the other hand, there were some significant differences between α-tocopherol, retinol, β-carotene, nitrite, nitrate, and ceruloplasmin levels of experimental groups. Results of present study showed that heroin withdrawal increased the lipid peroxidation and depressed endogenous antioxidative systems. Additionally, melatonin or vE + Se administrations prevented lipid peroxidation and augmented endogenous antioxidant defense systems.