SOX2 expression is associated with a cancer stem cell state and down-regulation of CDX2 in colorectal cancer

Background: To improve current treatment strategies for patients with aggressive colorectal cancer (CRC), the molecular understanding of subgroups of CRC with poor prognosis is of vast importance. SOX2 positive tumors have been associated with a poor patient outcome, but the functional role of SOX2 in CRC patient prognosis is still unclear. Methods: An in vitro cell culture model expressing SOX2 was used to investigate the functional role of SOX2 in CRC. In vitro findings were verified using RNA from fresh frozen tumor tissue or immunohistochemistry on formalin fixed paraffin embedded (FFPE) tumor tissue from a cohort of 445 CRC patients. Results: Using our in vitro model, we found that SOX2 expressing cells displayed several characteristics of cancer stem cells; such as a decreased proliferative rate, a spheroid growth pattern, and increased expression of stem cell markers CD24 and CD44. Cells expressing SOX2 also showed down-regulated expression of the intestinal epithelial marker CDX2. We next evaluated CDX2 expression in our patient cohort. CDX2 down-regulation was more often found in right sided tumors of high grade and high stage. Furthermore, a decreased expression of CDX2 was closely linked to MSI, CIMP-high as well as BRAF mutated tumors. A decreased expression of CDX2 was also, in a stepwise manner, strongly correlated to a poor patient prognosis. When looking at SOX2 expression in relation to CDX2, we found that SOX2 expressing tumors more often displayed a down-regulated expression of CDX2. In addition, SOX2 expressing tumors with a down-regulated CDX2 expression had a worse patient prognosis compared to those with retained CDX2 expression. Conclusions: Our results indicate that SOX2 expression induces a cellular stem cell state in human CRC with a decreased expression of CDX2. Furthermore, a down-regulated expression of CDX2 results in a poor patient prognosis in CRC and at least part of the prognostic importance of SOX2 is mediated through CDX2 down-regulation

The infiltration, and prognostic importance, of Th1 lymphocytes vary in molecular subgroups of colorectal cancer

Giving strong prognostic information, T-cell infiltration is on the verge of becoming an additional component in the routine clinical setting for classification of colorectal cancer (CRC). With a view to further improving the tools for prognostic evaluation, we have studied how Th1 lymphocyte infiltration correlates with prognosis not only by quantity, but also by subsite, within CRCs with different molecular characteristics (microsatellite instability, CpG island methylator phenotype status, and BRAF and KRAS mutational status). We evaluated the Th1 marker T-bet by immunohistochemistry in 418 archival tumour tissue samples from patients who underwent surgical resection for CRC. We found that a high number of infiltrating Th1 lymphocytes is strongly associated with an improved prognosis in patients with CRC, irrespective of intratumoural subsite, and that both extent of infiltration and patient outcome differ according to molecular subgroup. In brief, microsatellite instability, CpG island methylator phenotype-high and BRAF mutated tumours showed increased infiltration of Th1 lymphocytes, and the most pronounced prognostic effect of Th1 infiltration was found in these tumours. Interestingly, BRAF mutated tumours were found to be more highly infiltrated by Th1 lymphocytes than BRAF wild-type tumours whereas the opposite was seen for KRAS mutated tumours. These differences could be explained at least partly by our finding that BRAF mutated, in contrast to KRAS mutated, CRC cell lines and tumour specimens expressed higher levels of the Th1-attracting chemokine CXCL10, and reduced levels of CCL22 and TGFB1, stimulating Th2/Treg recruitment and polarisation. In conclusion, the strong prognostic importance of Th1 lymphocyte infiltration in CRC was found at all subsites evaluated, and it remained significant in multivariable analyses, indicating that T-bet may be a valuable marker in the clinical setting. Our results also indicate that T-bet is of value when analysed in molecular subgroups of CRC, allowing identification of patients with especially poor prognosis who are in need of extended treatment.Ytterligare finansiärer:Cancer Research Foundation in Northern Sweden (LP 12-1959 SE)Syskonen Svenssons Foundation for Medical Research (2014 SE)</p

The Combined Value of Faecal Haemoglobin andCalprotectin in Diagnosis of Colorectal Cancer inSymptomatic Patients Referred to Colonoscopy

Aim: To investigate the diagnostic value of a combined analyses of faecal immunological haemoglobin (FIT) and faecal calprotectin (FC) in detection of colorectal cancer (CRC). Methods: Out-patients (n=1440) referred to the endoscopy unit were analysed for FIT and FC in stool samples collected before the colonoscopy bowel preparation. The samples were collected from one defecation by the patients at home. Patients with IBD were excluded leaving stool samples from 1133 patients for further analyses. FIT was analysed using the immunological Analyse F.O.B Test and FC was analysed using the CALPRO® Calprotectin Elisa Test. Sensitivity and specificity to detect CRC was calculated for the individual tests, as well as for combined FIT/FC tests. Results: Out of the included patients, 38 were diagnosed with CRC, 9 with high grade dysplasia (HGD), and 133 with low grade dysplasia (LGD). FIT was analysed in 673 (59.4%), FC in 1021 (90.1%) and both FIT and FC in 561 (49.5%) patients. A ROC curve analysis showed that the most accurate cut-off level for FC in detecting CRC in our study was 105.5 µg/g. The sensitivity for CRC when using FIT, FC (cut-off &gt; 100 µg/g) and the combination of FIT and FC (at least one positive test) was 65.5%, 74.1% and 94.4%, respectively. The corresponding specificity was 84.8%, 74.9% and 68.3%, respectively. Conclusion: Combined analyses of FIT and FC improved sensitivity for detection of CRC. Further studies in larger cohorts are required to find the optimal cut-off levels for different combinations of tests

The Combined Value of Faecal Haemoglobin andCalprotectin in Diagnosis of Colorectal Cancer inSymptomatic Patients Referred to Colonoscopy

Aim: To investigate the diagnostic value of a combined analyses of faecal immunological haemoglobin (FIT) and faecal calprotectin (FC) in detection of colorectal cancer (CRC). Methods: Out-patients (n=1440) referred to the endoscopy unit were analysed for FIT and FC in stool samples collected before the colonoscopy bowel preparation. The samples were collected from one defecation by the patients at home. Patients with IBD were excluded leaving stool samples from 1133 patients for further analyses. FIT was analysed using the immunological Analyse F.O.B Test and FC was analysed using the CALPRO® Calprotectin Elisa Test. Sensitivity and specificity to detect CRC was calculated for the individual tests, as well as for combined FIT/FC tests. Results: Out of the included patients, 38 were diagnosed with CRC, 9 with high grade dysplasia (HGD), and 133 with low grade dysplasia (LGD). FIT was analysed in 673 (59.4%), FC in 1021 (90.1%) and both FIT and FC in 561 (49.5%) patients. A ROC curve analysis showed that the most accurate cut-off level for FC in detecting CRC in our study was 105.5 µg/g. The sensitivity for CRC when using FIT, FC (cut-off &gt; 100 µg/g) and the combination of FIT and FC (at least one positive test) was 65.5%, 74.1% and 94.4%, respectively. The corresponding specificity was 84.8%, 74.9% and 68.3%, respectively. Conclusion: Combined analyses of FIT and FC improved sensitivity for detection of CRC. Further studies in larger cohorts are required to find the optimal cut-off levels for different combinations of tests

The Combined Value of Faecal Haemoglobin andCalprotectin in Diagnosis of Colorectal Cancer inSymptomatic Patients Referred to Colonoscopy

Aim: To investigate the diagnostic value of a combined analyses of faecal immunological haemoglobin (FIT) and faecal calprotectin (FC) in detection of colorectal cancer (CRC). Methods: Out-patients (n=1440) referred to the endoscopy unit were analysed for FIT and FC in stool samples collected before the colonoscopy bowel preparation. The samples were collected from one defecation by the patients at home. Patients with IBD were excluded leaving stool samples from 1133 patients for further analyses. FIT was analysed using the immunological Analyse F.O.B Test and FC was analysed using the CALPRO® Calprotectin Elisa Test. Sensitivity and specificity to detect CRC was calculated for the individual tests, as well as for combined FIT/FC tests. Results: Out of the included patients, 38 were diagnosed with CRC, 9 with high grade dysplasia (HGD), and 133 with low grade dysplasia (LGD). FIT was analysed in 673 (59.4%), FC in 1021 (90.1%) and both FIT and FC in 561 (49.5%) patients. A ROC curve analysis showed that the most accurate cut-off level for FC in detecting CRC in our study was 105.5 µg/g. The sensitivity for CRC when using FIT, FC (cut-off &gt; 100 µg/g) and the combination of FIT and FC (at least one positive test) was 65.5%, 74.1% and 94.4%, respectively. The corresponding specificity was 84.8%, 74.9% and 68.3%, respectively. Conclusion: Combined analyses of FIT and FC improved sensitivity for detection of CRC. Further studies in larger cohorts are required to find the optimal cut-off levels for different combinations of tests

Secreted Factors from Colorectal and Prostate Cancer Cells Skew the Immune Response in Opposite Directions

Macrophage infiltration has been associated with an improved prognosis in patients with colorectal cancer (CRC), but a poor prognosis in prostate cancer (PC) patients. In this study, the distribution and prognostic value of proinflammatory M1 macrophages (NOS2(+)) and immunosuppressive M2 macrophages (CD163(+)) was evaluated in a cohort of 234 PC patients. We found that macrophages infiltrating PC were mainly of an M2 type and correlated with a more aggressive tumor and poor patient prognosis. Furthermore, the M1/M2 ratio was significantly decreased in PC compared to CRC. Using in vitro cell culture experiments, we could show that factors secreted from CRC and PC cells induced macrophages of a proinflammatory or immunosuppressive phenotype, respectively. These macrophages differentially affected autologous T lymphocyte proliferation and activation. Consistent with this, CRC specimens were found to have higher degrees of infiltrating T-helper 1 cells and active cytotoxic T lymphocytes, while PC specimens displayed functionally inactive T cells. In conclusion, our results imply that tumour-secreted factors from cancers of different origin can drive macrophage differentiation in opposite directions and thereby regulate the organization of the anti-tumour immune response. Our findings suggest that reprogramming of macrophages could be an important tool in the development of new immunotherapeutic strategies

The gene expression profiles of the different macrophage populations.

<p>Gene expression was studied in M1 and M2 macrophages, or macrophages stimulated with conditioned media (Cm) from RKO, SW480 or Caco2 CRC cell lines using a Cytokine & Chemokine PCR Array. (A) Expression of pro-inflammatory and anti-inflammatory cytokines. (B) Expression of chemotactic factors. Shown is fold gene expression, with IL4 stimulated M2 macrophages set as 1.</p

Effects on the macrophage phenotype by secreted factors from CRC cells.

<p>(A) Morphological evaluation of macrophages stimulated with conditioned media (Cm) from RKO, SW480 or Caco2 cell lines. (B) Expression of extracellular markers was evaluated by immunostaining and flow cytometry in macrophages of M1 and M2 subtype or in macrophages stimulated with conditioned media (Cm) from CRC cell lines. Relative mean flourescense intensity (MFI) ± SD of three or more independent experiments is shown, where each sample was normalized against its respective isotype control and with the M-CSF stimulated control sample set as 1.</p

SOX2 expression is regulated by BRAF and contributes to poor patient prognosis in colorectal cancer

Sporadic colorectal cancer (CRC) is a common malignancy and also one of the main causes of cancer deaths worldwide. Aberrant expression of the transcription factor SOX2 has recently been observed in several cancer types, but its role in CRC has not been fully elucidated. Here we studied the expression of SOX2 in 441 CRC patients by immunohistochemistry and related the expression to clinicopathological and molecular variables and patient prognosis. SOX2 was expressed in 11% of the tumors and was significantly associated to BRAF(V600E) mutation, but not to KRAS mutations (codon 12 and 13). SOX2 positivity was correlated to poor patient survival, especially in BRAF(V600E) mutated cases. In vitro studies showed that cells expressing the constitutively active BRAF(V600E) had increased SOX2 expression, a finding not found in cells expressing KRAS(G12V). Furthermore, blocking downstream BRAF signalling using a MEK-inhibitor resulted in a decreased expression of SOX2. Since SOX2 overexpression has been correlated to increased migration and invasion, we investigated the SOX2 expression in human CRC liver metastasis and found that a SOX2 positive primary CRC also had SOX2 expression in corresponding liver metastases. Finally we found that cells overexpressing SOX2 in vitro showed enhanced expression of FGFR1, which has been reported to correlate with liver metastasis in CRC. Our novel findings suggest that SOX2 expression is partly regulated by BRAF signalling, and an increased SOX2 expression may promote CRC metastasis and mediate a poor patient prognosis

Vale la pena aprender Ética profesional

Estas diapositivas formaron parte de la conferencia del XVI Simposium de Educación, en donde la a autora presenta la importancia de la ética profesional en la formación universitaria. Presenta resultados de una investigación con estudiantes de posgrado de la UNAM, sus reflexiones sobre el significado de ser un buen profesional