Project description:The pro-tumourigenic role of epithelial TGFβ in colorectal cancer (CRC) has been controversial. Here we identify a cohort of aggressive ‘bad acting’ early-stage (T1) disseminating tumours characterised by high cell-intrinsic TGFβ signalling emanating from the epithelium, not stroma. To address its functional significance, we activated TGFβ signalling in the murine intestinal epithelium either alone or in concert with the common tumour suppressive and oncogenic mutations found in CRC, namely Apc and Kras. Consistent with previous studies, we found that activation of TGFβ rapidly induced apoptosis in Apc-mutant intestine and completely killed Apc-mutant organoids. However, in the presence of both Apc and Kras mutation, activation of TGFβ within the epithelium rampantly accelerates tumourigenesis. Importantly the transcriptional signatures derived from these mice overlapped with the “bad acting” T1 human tumours and this signalling could also predict recurrence in stage II CRC. Mechanistically, the activation of intrinsic TGFβ induced the expression of a growth-factor signalling module containing EGFR that synergised with Apc and Kras to drive marked activation of MAPK signalling. Importantly, inhibition of MEK and/or EGFR suppressed the acceleration conferred by TGFβ even in Kras-mutant cells, which are refractory to MEK/EGFR inhibition in the absence of epithelial TGFβ. Together, we identify both a determinant of early dissemination and a potential vulnerability for tumours with these born-to-be-bad traits.

2021-08-13 | GSE182019 | GEO

Wnt signalling in colon cancer

Project description:Hypothesis and proof of concept: Our hypothesis is that increase in cellular iron import proteins (TfR1, DMT1) occur early in the adenoma-carcinoma sequence through mutations in APC and lead to cellular iron loading. As demonstrated in our previous work the effects of this iron loading is to mediate increased Wnt signalling resulting in c-myc induction. This in turn serves to increase the expression of iron import proteins (TfR1, DMT1) and decrease the expression of iron export (ferroportin [FPN]) and storage (ferritin) proteins. Such a hypothesis explains how Wnt signalling controls iron metabolism and ensures that there is adequate cellular iron for ATP generation and cellular proliferation. Experimental design: To test such a hypothesis we aim to prospectively collect the following colorectal tissue from patients attending for colonoscopy: 1. Normal colonic mucosa in patients with no colorectal pathology (n = 30) 2. Polyps and matched normal colon (n = 30) 3. Colorectal cancers and matched normal colon (n = 30) We also intend to collect serum and urine from the following patient groups: 4. Normal colonoscopy (n = 30) 5. Colorectal adenomas (n = 30) 6. Colorectal cancers (n = 30) Primary outcome(s): Measured at baseline, using the expression of proteins in the tissue and serum to detect the cellular and systemic iron transport proteins. The techniques used will include mass spectrometry, western blotting, real time PCR and immunohistochemistry.

| 2416626 | ecrin-mdr-crc

Brg1 loss attenuates aberrant wnt-signalling and prevents wnt-dependent tumourigenesis in the murine small intestine.

Project description: Not available

| S-EPMC4091792 | biostudies-literature

ZBTB20 regulates WNT/CTNNB1 signalling pathway by suppressing PPARG during hepatocellular carcinoma tumourigenesis.

Project description: Not available

| S-EPMC7873381 | biostudies-literature