Mathilde Jalving

Metformin: Taking away the candy for cancer?

Metformin is widely used in the treatment of diabetes mellitus type 2 where it reduces insulin resistance and diabetes-related morbidity and mortality. Population-based studies show that metformin treatment is associated with a dose-dependent reduction in cancer risk. The metformin treatment also increases complete pathological tumour response rates following neoadjuvant chemotherapy for breast cancer, suggesting a potential role as an anti-cancer drug. Diabetes mellitus type 2 is associated with insulin resistance, elevated insulin levels and an increased risk of cancer and cancer-related mortality. This increased risk may be explained by activation of the insulin- and insulin-like growth factor (IGF) signalling pathways and increased signalling through the oestrogen receptor. Reversal of these processes through reduction of insulin resistance by the oral anti-diabetic drug metformin is an attractive anti-cancer strategy. Metformin is an activator of AMP-activated protein kinase (AMPK) which inhibits protein synthesis and gluconeogenesis during cellular stress. The main downstream effect of AMPK activation is the inhibition of mammalian target of rapamycin (mTOR), a downstream effector of growth factor signalling. mTOR is frequently activated in malignant cells and is associated with resistance to anticancer drugs. Furthermore, metformin can induce cell cycle arrest and apoptosis and can reduce growth factor signalling. This review discusses the role of diabetes mellitus type 2 and insulin resistance in carcinogenesis, the preclinical rationale and potential mechanisms of metformins anti-cancer effect and the current and future clinical developments of metformin as a novel anti-cancer drug.

Increased risk of fundic gland polyps during long-term proton pump inhibitor therapy

It is controversial whether proton pump inhibitor use leads to fundic gland polyp development.

Review article: the potential of combinational regimen with non-steroidal anti-inflammatory drugs in the chemoprevention of colorectal cancer

Non‐steroidal anti‐inflammatory drugs are chemopreventive agents in colorectal cancer. Non‐steroidal anti‐inflammatory drugs do not, however, offer complete protection against adenoma and carcinoma development. There is increasing interest in combining non‐steroidal anti‐inflammatory drugs with agents that target specific cell signalling pathways in malignant and premalignant cells.

Dysplasia in fundic gland polyps is associated with nuclear beta-catenin expression and relatively high cell turnover rates

Background: Fundic gland polyps (FGPs) occur in both syndromic and sporadic form. Syndromic FGPs arise through mutations in the adenomatous polyposis coli (APC) gene, whereas sporadic FGPs are caused by

TRAIL Induces Apoptosis in Human Colorectal Adenoma Cell Lines and Human Colorectal Adenomas

-catenin gene mutations. Dysplasia in sporadic FGPs, found less often than in syndromic FGPs, was recently associated with APC rather than

Independent induction of caspase-8 and cFLIP expression during colorectal carcinogenesis in sporadic and HNPCC adenomas and carcinomas

-catenin mutations. These data suggest different functional consequences of APC and

Theranostics Using Antibodies and Antibody-Related Therapeutics

-catenin mutations. To investigate this hypothesis, we examined proliferative activity, degree of apoptosis, # -catenin expression and p53 expression in syndromic and sporadic FGPs. Methods: Syndromic FGPs ( n r = r 9) from familial adenomatous polyposis (FAP) patients and sporadic FGPs ( n r = r 18) were studied. Proliferative activity, apoptotic cell death and expression of # -catenin and p53 were examined by immunohistochemistry. In FGPs containing dysplasia, areas with and without dysplasia were compared. Results: Syndromic and sporadic FGPs without dysplasia exhibited similar proliferative activity, degree of apoptosis, # -catenin and p53 expression. Dysplasia was observed more often in syndromic (4/9) than in sporadic FGPs (1/18). Within FGPs containing dysplasia, dysplastic areas showed abnormal nuclear # -catenin staining in 3/5 cases and higher rates of cell proliferation and apoptosis than non-dysplastic areas. Overexpression of p53 was not observed. Conclusion: The finding of similar rates of proliferation and apoptosis in syndromic and sporadic FGPs does not support the hypothesis that APC and

Cancer-drug induced insulin resistance: Innocent bystander or unusual suspect

-catenin gene mutations have different functional consequences in FGPs. The association of dysplasia with relatively high cell turnover rates and nuclear expression of

Targeting breast cancer through its microenvironment: current status of preclinical and clinical research in finding relevant targets.

- catenin indicates activation of the Wnt-APC- # -catenin pathway in dysplasia. The finding of dysplasia in some but not all syndromic FGPs suggests the involvement of other genes in addition to the APC gene in the development of dysplasia in FGPs.BACKGROUND Fundic gland polyps (FGPs) occur in both syndromic and sporadic form. Syndromic FGPs arise through mutations in the adenomatous polyposis coli (APC) gene, whereas sporadic FGPs are caused by beta-catenin gene mutations. Dysplasia in sporadic FGPs, found less often than in syndromic FGPs, was recently associated with APC rather than beta-catenin mutations. These data suggest different functional consequences of APC and beta-catenin mutations. To investigate this hypothesis, we examined proliferative activity, degree of apoptosis, beta-catenin expression and p53 expression in syndromic and sporadic FGPs. METHODS Syndromic FGPs (n = 9) from familial adenomatous polyposis (FAP) patients and sporadic FGPs (n = 18) were studied. Proliferative activity, apoptotic cell death and expression of beta-catenin and p53 were examined by immunohistochemistry. In FGPs containing dysplasia, areas with and without dysplasia were compared. RESULTS Syndromic and sporadic FGPs without dysplasia exhibited similar proliferative activity, degree of apoptosis, beta-catenin and p53 expression. Dysplasia was observed more often in syndromic (4/9) than in sporadic FGPs (1/18). Within FGPs containing dysplasia, dysplastic areas showed abnormal nuclear beta-catenin staining in 3/5 cases and higher rates of cell proliferation and apoptosis than non-dysplastic areas. Overexpression of p53 was not observed. CONCLUSION The finding of similar rates of proliferation and apoptosis in syndromic and sporadic FGPs does not support the hypothesis that APC and beta-catenin gene mutations have different functional consequences in FGPs. The association of dysplasia with relatively high cell turnover rates and nuclear expression of beta-catenin indicates activation of the Wnt-APC-beta-catenin pathway in dysplasia. The finding of dysplasia in some but not all syndromic FGPs suggests the involvement of other genes in addition to the APC gene in the development of dysplasia in FGPs.

TNF-related apoptosis-inducing ligand cooperates with NSAIDs via activated Wnt signalling in (pre)malignant colon cells

Purpose: Recombinant human (rh) tumor necrosis factor–related apoptosis-inducing ligand (TRAIL) is a potential new anticancer drug which can induce apoptosis in colorectal cancer cell lines. The aim of this study was to investigate whether it is possible to induce apoptosis in human adenoma cell lines and human adenomas using rhTRAIL. Experimental Design: Two human adenoma cell lines were exposed to 0.1 μg/mL of rhTRAIL for 5 hours. Apoptosis and caspase activation in cell lines were evaluated using immunocytochemistry, fluorimetric caspase assays, and Western blotting. Short-term explant cultures were established from freshly removed human adenomas (n = 38) and biopsies of normal colon epithelium (n = 15), and these were incubated for 5 hours in the presence or absence of 1 μg/mL of rhTRAIL. Apoptosis was determined in paraffin-embedded tissue using morphologic criteria and cleaved caspase-3 staining. Results: In the adenoma cell lines, rhTRAIL induced up to 55% apoptosis. This coincided with caspase-8 and caspase-3 activation and could be inhibited by a pan-caspase inhibitor. rhTRAIL induced caspase-dependent apoptosis in adenomas with high-grade dysplasia (n = 21) compared with the paired untreated counterparts (apoptotic index, 34 ± 5% versus 17 ± 2%, mean ± SE; P = 0.002), but not in adenomas with low-grade dysplasia (n = 17) or in normal colon epithelium (n = 15). Conclusions: Colorectal adenoma cell lines and adenomas with high-grade dysplasia are sensitive to rhTRAIL-induced apoptosis, whereas normal colon epithelium is not. This suggests the potential application of rhTRAIL in the treatment of adenomas with high-grade dysplasia.