No abstract availble.
Anticarcinogenic Agents/*therapeutic use ; Aspirin/*therapeutic use ; Colonic Neoplasms/*prevention & control ; Humans

Basal autophagy plays a critical role in maintaining cellular homeostasis and genomic integrity by degrading aged or malfunctioning organelles and damaged or misfolded proteins. However, autophagy also plays a complicated role in tumorigenesis and treatment responsiveness. It can be tumor-suppressing during the early stages of tumorigenesis (i.e., it is an anti-tumor mechanism), as reduced autophagy is found in tumor cells and may be associated with malignant transformation. In this case, induction of autophagy would seem to be beneficial for cancer prevention. In established tumors, however, autophagy can be tumor-promoting (i.e., it is a pro-tumor mechanism), and cancer cells can use enhanced autophagy to survive under metabolic and therapeutic stress. The pharmacological and/or genetic inhibition of autophagy was recently shown to sensitize cancer cells to the lethal effects of various cancer therapies, including chemotherapy, radiotherapy and targeted therapies, suggesting that suppression of the autophagic pathway may represent a valuable sensitizing strategy for cancer treatments. In contrast, excessive stimulation of autophagy may also provide a therapeutic strategy for treating resistant cancer cells having high apoptotic thresholds. In order for us to develop successful autophagy-modulating strategies against cancer, we need to better understand how the roles of autophagy differ depending on the tumor stage, cell type and/or genetic factors, and we need to determine how specific pathways of autophagy are activated or inhibited by the various anti-cancer therapies.
Anticarcinogenic Agents/therapeutic use ; Autophagy/*physiology ; Cell Transformation, Neoplastic/drug effects ; Humans ; Neoplasms/*drug therapy/metabolism/*pathology

In the western world, prostate cancer is a most common malignant neoplasm in human males. In recent years, its incidence has been rising dramatically in China. Prevention of this disease would have a positive impact on the disease-related cost, morbidity, and mortality for a large portion of the population. Cancer chemoprevention is defined as the use of natural, synthetic or biologic chemical agents to reverse, suppress, or prevent carcinogenic progression to invasive cancer. This article reviews the progress in chemoprevention of prostate cancer.
Aged ; Aged, 80 and over ; Anticarcinogenic Agents ; therapeutic use ; Chemoprevention ; Humans ; Male ; Middle Aged ; Prostatic Neoplasms ; prevention & control

The development of gastric cancer is a multi-factor process. In addition to genetic factors, environmental factors including smoking, low gastric acidity, excessive intake of salt or salty food and low consumption of fresh fruits and vegetables all contribute to the development of gastric cancer. Of particular interest, epidemiological and experimental studies have demonstrated that Helicobacter pylori (H. pylori) infection is causally linked to gastric cancer. Most studies using micronutrient supplementation have failed to demonstrate any preventive effect against the development of gastric cancer. The use of non-steroidal anti-inflammatory drugs has been consistently observed to protect against the development of gastric cancer. Recently, eradication of H. pylori infection by a chemopreventative approach is being studied in a number of trials. Studies using precancerous lesions as an end point of the treatment have produced conflicting and mostly negative results. Trials using cancer as an end point are being cautiously carried out in high-risk populations, and will provide the definitive answer to this important question. In the end, vaccination may be proven to be the optimal strategy in human for the management of H. pylori infection and prevention of gastric cancer.
Anti-Inflammatory Agents, Non-Steroidal ; therapeutic use ; Anticarcinogenic Agents ; therapeutic use ; Dietary Supplements ; Helicobacter Infections ; complications ; drug therapy ; prevention & control ; Humans ; Stomach Neoplasms ; etiology ; prevention & control ; Vaccination

Anticarcinogenic Agents ; pharmacology ; therapeutic use ; Diterpenes, Abietane ; Humans ; Medical Oncology ; methods ; trends ; Medicine, Chinese Traditional ; methods ; trends ; Neoplasm Metastasis ; prevention & control ; Neoplasms ; drug therapy ; Phenanthrenes ; pharmacology ; therapeutic use

Adult ; Anticarcinogenic Agents ; therapeutic use ; Breast Neoplasms ; drug therapy ; pathology ; Disease Progression ; Female ; Humans ; Interdisciplinary Communication ; Neoplasm Staging ; Pregnancy ; Pregnancy Complications, Neoplastic ; drug therapy ; pathology ; Treatment Outcome

OBJECTIVETo evaluate the roles of folic acid and beta-carotene in the chemoprevention of gastric and other gastrointestinal (GI) cancers.

METHODSIn a randomized, double-blind, placebo-controlled trial, a total of 216 patients with atrophic gastritis were randomly assigned to one of the four groups: (1) folate (FA, 20 mg per day plus vitamin B(12) 1 mg, intramuscularly, per month for one year, then 20 mg two times a week plus 1 mg per three months for the next year); (2) natural beta-carotene (N-betaC, 30 mg per day for first year, then 30 mg two times a week for the next); (3) synthetic beta-carotene (S-betaC, administered as in N-betaC); and (4) placebo. Follow-ups continued from 1994 to 2001.

RESULTSA total of 7 new cases of gastrointestinal cancers were diagnosed with 3 stomach, 1 colon and 1 esophageal cancers occurring in the placebo group; 1 stomach cancer in both of the N-betaC and S-betaC groups, and no cancer occurring in FA group. In terms of GI cancers, there was a significant reduction in the FA group, compared with the placebo group (P = 0.04). A similar trend was observed in both N-betaC and S-betaC groups (P = 0.07 - 0.08). Taken together, the three intervention groups displayed a highly significant decrease in occurrence (P = 0.004, vs placebo), and a lower risk for GI cancers (OR = 0.12; 95% confidence interval, 0.03 - 0.51). For development of gastric cancer, any one of the three active-treated groups did not reach statistically significant reduction. The FA group showed obvious improvement of the gastric mucosal lesions with more patients displaying lesions reversed or stable atrophy and inflammation (P = 0.04), reversed intestinal metaplasia (P = 0.06) at the end of follow-up, and reversed displasia (P = 0.017) at 12 months. Two cases of false jaundice were found in beta-carotene groups with no influence on administration, and no side-effects were reported in FA group.

CONCLUSIONSThis trial revealed the interventional effect of folic acid on the development of GI cancers, a similar effect of beta-carotene was also detected. Also, folic acid may be of use to treat atrophic gastritis by preventing or reversing the precancerous lesions.

Adult ; Aged ; Anticarcinogenic Agents ; therapeutic use ; Double-Blind Method ; Female ; Folic Acid ; adverse effects ; therapeutic use ; Gastric Mucosa ; pathology ; Gastrointestinal Neoplasms ; prevention & control ; Humans ; Male ; Middle Aged ; Patient Compliance ; Stomach Neoplasms ; prevention & control ; beta Carotene ; therapeutic use

OBJECTIVECalcium Glucarate (Cag), Ca salt of D-glucaric acid is a naturally occurring non-toxic compound present in fruits, vegetables and seeds of some plants, and suppress tumor growth in different models. Due to lack of knowledge about its mode of action its uses are limited in cancer chemotherapy thus the objective of the study was to study the mechanism of action of Cag on mouse skin tumorigenesis.

METHODSWe have estimated effect of Cag on DMBA induced mouse skin tumor development following complete carcinogenesis protocol. We measured, epidermal transglutaminase activity (TG), a marker of cell differentiation after DMBA and/or Cag treatment and [3H] thymidine incorporation into DNA as a marker for cell proliferation.

RESULTSTopical application of Cag suppressed the DMBA induced mouse skin tumor development. Topical application of Cag significantly modifies the critical events of proliferation and differentiation TG activity was found to be reduced after DMBA treatment. Reduction of the TG activity was dependent on the dose of DMBA and duration of DMBA exposure. Topical application of Cag significantly alleviated DMBA induced inhibition of TG. DMBA also caused stimulation of DNA synthesis in epidermis, which was inhibited by Cag.

CONCLUSIONCag inhibits DMBA induced mouse skin tumor development. Since stimulation of DNA synthesis reflects proliferation and induction of TG represents differentiation, the antitumorigenic effect of Cag is considered to be possibly due to stimulation of differentiation and suppression of proliferation.

9,10-Dimethyl-1,2-benzanthracene ; toxicity ; Administration, Topical ; Animals ; Anticarcinogenic Agents ; therapeutic use ; Carcinogens ; toxicity ; Cell Division ; drug effects ; DNA ; biosynthesis ; Enzyme Inhibitors ; toxicity ; Female ; Glucaric Acid ; therapeutic use ; Mice ; Skin Neoplasms ; chemically induced ; enzymology ; prevention & control ; Thymidine ; metabolism ; Transglutaminases ; metabolism

BACKGROUNDGreen tea is an important source of flavonoids in human diets and epidemiological data correlate green tea consumption with a reduced cancer risk. Given its complicated properties at effective concentrations, we put epigallocatechin-3-gallate (EGCG) that previously reported on its anti-proliferative activities against several cancer cell lines on our research agenda to further examine the mechanism of its chemopreventive potential.

METHODSRNA interference (RNAi) expression vector pSilencer 3.1-H1 was used to construct recombinant nuclear factor erythroid 2 related factor 2 (Nrf2)-targeting RNAi plasmids. EGCG (5 microg/ml) was added into the culture fluid of cells before and after transfection. RT-PCR and Western blotting were used to detect the expression of uridine 5'-diphosphate-glucuronosyltransferase (UGT) 1A in cells. Forty male BALB/c mice were assigned to four groups: a normal unexposed control and three groups treated with varying doses of EGCG. Four weeks later, the mice were sacrificed, and their colon tissues were subjected to mRNA and protein expression of Nrf2 and UGT1A via RT-PCR and Western blotting analysis.

RESULTSEGCG up-regulated the expression of Nrf2 and increased the level of UGT1A in cells. The blockade of Nrf2 activity via RNA intervention largely attenuated the induction of UGT1A expression by EGCG. In mice, the mRNA and protein levels of Nrf2 and UGT1A detected by RT-PCR and Western blotting increased (both P < 0.05 compared with the control). This increase in Nrf2 expression also had a positive correlation with an increased UGT1A expression.

CONCLUSIONSEGCG mediated its effect in part by inducing the NRF2 signaling pathway and increasing UGT1A expression. Both in vitro and in vivo studies demonstrated the role of NRF2 and UGT1A expression in the potential use of EGCG as a possible chemopreventive agent and supported further study of EGCG for cancer treatment.

Animals ; Anticarcinogenic Agents ; pharmacology ; therapeutic use ; Blotting, Western ; Caco-2 Cells ; Catechin ; analogs & derivatives ; pharmacology ; therapeutic use ; Colonic Neoplasms ; drug therapy ; metabolism ; Gene Expression Regulation ; Gene Expression Regulation, Neoplastic ; Glucuronosyltransferase ; genetics ; metabolism ; Humans ; Male ; Mice ; Mice, Inbred BALB C ; NF-E2-Related Factor 2 ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction

Metastasis is the main cause of death in cancer patients. To improve the outcomes of patients undergoing a surgery, new adjuvant therapies that can effectively inhibit metastases have to be developed. Studies have shown that flavonoid naringenin, a natural product that is mainly present in grapes and citrus, may contribute to cancer prevention. It has many advantages compared to traditional chemotherapeutic drugs, such as low toxicity. To determine whether naringenin can also inhibit metastases, a breast cancer resection model that mimics clinical situations was established. We found that orally administered naringenin significantly decreased the number of metastatic tumor cells in the lung and extended the life span of tumor resected mice. Flow cytometry analysis revealed that T cells displayed enhanced antitumor activity in naringenin treated mice, with an increased proportion of IFN-γ and IL-2 expressing T cells. In vitro studies further demonstrated that relief of immunosuppression caused by regulatory T cells might be the fundamental mechanism of metastasis inhibition by naringenin. These results indicate that orally administered naringenin can inhibit the outgrowth of metastases after surgery via regulating host immunity. Thus, naringenin can be an ideal surgical adjuvant therapy for breast cancer patients.
Animals ; Anticarcinogenic Agents ; administration & dosage ; therapeutic use ; Antigens, CD ; analysis ; Breast Neoplasms ; drug therapy ; immunology ; pathology ; surgery ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Chemotherapy, Adjuvant ; Female ; Flavanones ; administration & dosage ; therapeutic use ; Humans ; Immunosuppressive Agents ; administration & dosage ; therapeutic use ; Interferon-gamma ; biosynthesis ; immunology ; Interleukin-2 ; biosynthesis ; immunology ; Lung Neoplasms ; drug therapy ; immunology ; prevention & control ; secondary ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; T-Lymphocytes, Regulatory ; drug effects ; immunology ; metabolism