Selja Koskensalo

MMP-7 as a prognostic marker in colorectal cancer

Matrix metalloproteinase-7 is capable of degrading many extracellular matrix proteins and cellular adhesions. In many malignancies, it is overexpressed, and it plays a role in cancer progression by enhancing tumor invasion and thereby metastatic potential. The purpose of this study was to evaluate the association between MMP-7 tissue expression and prognosis in colorectal cancer. From 623 patients who underwent surgery for colorectal cancer, surgical specimens were collected into tissue array blocks and stained by immunohistochemistry for MMP-7. Specimens from 545 patients were suitable for analysis. In specimens from 105 patients (19.3%), MMP-7 scored as high; in 103 (18.9%), as moderate; and in 134 (24.9%), as mild. In 203 cases (37.2%), immunoreactivity was negative. A significant correlation appeared between MMP-7 immunoexpression and tumor differentiation. High MMP-7 positivity associated with poor prognosis during a 5-year follow-up. During longer follow-up, the differences in survival between groups disappeared. MMP-7 is a potential target for tumor therapy, which should be evaluated in clinical trials.

MMP-7 overexpression is an independent prognostic marker in gastric cancer

To enable cancer to invade and to metastasize, the surrounding stroma must be degraded. Matrix metalloproteinase-7 (MMP-7) is capable of degrading many extracellular matrix proteins and cellular adhesions, is overexpressed in many malignancies, and plays a role in tumour progression. The purpose of this study was to evaluate the association between MMP-7 tissue expression and patients’ prognosis in gastric cancer. From 264 patients who underwent surgery for gastric cancer, surgical specimens were collected on tissue array blocks and stained by immunohistochemistry for MMP-7. In 27 (10.2%) of the specimens, immunopositivity was found as high, in 50 (18.9%) as moderate and in 51 (19.3%) as weak. In 136 cases (51.5%), the immunopositivity was negative. A statistically significant correlation appeared between high MMP-7 expression and poor survival. In conclusion, our results suggest that MMP-7 expression may prove helpful in evaluating gastric cancer prognosis.

CIP2A overexpression is associated with c-Myc expression in colorectal cancer

Background: To improve the prognostic evaluation of colorectal cancer requires new molecular markers. Cancerous inhibitor of protein phosphatase 2A (CIP2A) serves as an oncoprotein by targeting PP2A-mediated inhibition of c-Myc. A prognostic role for CIP2A has been demonstrated in gastric, lung, and tongue cancers. Methods: 863 consecutive colorectal cancer patients treated at Helsinki University Central Hospital in 1983-2001 were collected with 752 scored successfully for CIP2A immunohistochemical expression from tumor tissue microarrays. Associations with clinicopathologic variables and molecular markers were explored by the chi-square test, and the Kaplan-Meier method served for survival analysis. Results: CIP2A was overexpressed in 661 (87.9%) specimens. CIP2A overexpression was associated with tumor differentiation grade (p = 0.014), p53 immunopositivity (p = 0.042), EGFR immunopositivity (p = 0.007), and c-Myc nuclear immunopositivity (p = 0.018). In survival analysis, CIP2A failed to show any prognostic significance (p = 0.270, log-rank test). Conclusions: Overexpression of CIP2A in colorectal cancer patients may be an important step in colorectal carcinogenesis. Based on our findings, CIP2A shows no association with patient prognosis in colorectal cancer, but is associated with nuclear c-Myc.

Tumour-associated trypsin inhibitor TATI is a prognostic marker in colorectal cancer.

Background: The tumour-associated trypsin inhibitor TATI is expressed together with trypsin in many cancer forms, and an elevated serum level associates with poor prognosis. TATI can reduce tissue destruction by inhibiting trypsin and other proteinases, and in some cancer forms, its high tissue expression is associated with favourable prognosis. We analyzed the prognostic values of TATI, trypsinogen-1 and trypsinogen-2 immunoexpression from tissue array blocks constructed from surgical specimens of 592 colorectal cancer patients. Results: TATI positivity correlated negatively with differentiation (p < 0.001) and positively with the histological type of adenocarcinoma (p < 0.001). Trypsinogen-1 and trypsinogen-2 positivity correlated with Dukes’ stage (p = 0.045, p = 0.050); the percentage of trypsinogen-1- and trypsinogen-2-positive tumours was lower in metastasized (Dukes’ stage C–D) than in local (Dukes’ stage A–B) disease. In addition, trypsinogen-2 correlated inversely with differentiation (p = 0.012). In univariate analysis, the expression of TATI associated with more favourable cancer-specific survival (p = 0.010). In multivariate analysis, low TATI (p = 0.044), age (p < 0.001), Dukes’ stage (p < 0.001), tumour differentiation (p = 0.020) and location in the rectum (p = 0.006) were independent prognostic factors for adverse outcome. Furthermore, TATI expression was an independent prognostic factor in a subgroup of trypsinogen-1- (p = 0.007) and trypsinogen-2-positive (p = 0.006) tumours. Conclusion: TATI tissue expression is an independent prognostic marker in colorectal cancer.

Concomitant Tumor Expression of EGFR and TATI/SPINK1 Associates with Better Prognosis in Colorectal Cancer

Background Epidermal growth factor receptor (EGFR) activation plays a role in colorectal cancer (CRC) carcinogenesis, and anti-EGFR drugs are used in treatment of advanced CRC. One of the EGFR ligands is tumor-associated trypsinogen inhibitor TATI, also called serine protease inhibitor Kazal type1 (SPINK 1), which we recently showed to be an independent prognostic marker in CRC. Methods We studied the prognostic value of immunohistochemical expression of EGFR and concomitant expression of EGFR and TATI/SPINK1 in a series of 619 colorectal cancer patients. Results Of the samples, 92% were positive for EGFR. EGFR+/TATI+ was seen in 62.8%, EGFR+/TATI− in 29.5%, EGFR−/TATI+ in 4.9%, and EGFR−/TATI− in 2.7% of patients. EGFR expression correlated with WHO grade (p = 0.040). In univariate analysis, EGFR expression correlated with favourable survival (p = 0.006). EGFR+/TATI+ patients showed better survival than did those with other combinations (p<0.001). In multivariate analysis, EGFR+/TATI+ was an independent prognostic factor of favourable prognosis (p<0.001). Conclusion Concomitant positivity of EGFR and TATI/SPINK1 predicts favourable prognosis in CRC.

Lack of MMP-9 expression is a marker for poor prognosis in Dukes’ B colorectal cancer

BackgroundMatrix metalloproteinases (MMPs) play a role in cancer progression by degrading extracellular matrix and basement membranes, assisting in tumour neovascularization and in supporting immune response in cancer.MethodsWe studied the prognostic value of immunohistochemical expression of MMP-2, MMP-8, and MMP-9 in a series of 619 colorectal cancer patients using tissue microarray specimens.ResultsOf the samples, 56% were positive for MMP-2, 78% for MMP-8, and 60% for MMP-9. MMP-9 associated with low WHO grade (p < 0.001). In univariate analysis of Dukes’ B tumours, MMP-9 negativity associated with poor survival (p = 0.018), and MMP-9 positivity was an independent prognostic marker in multivariate analysis of these tumours (p = 0.034).ConclusionNegative MMP-9 expression can predict poor prognosis in Dukes’ B colorectal tumours and may prove useful for identifying patients, who should be offered adjuvant treatment.

Carbonic anhydrase enzymes II, VII, IX and XII in colorectal carcinomas

AIM To investigate expression of four alpha-carbonic anhydrases (CAs) in colorectal carcinomas (CRC) and compare the results with patients’ survival. METHODS Colorectal carcinoma samples from 539 CRC patients and control tissues were arranged as tissue microarrays and analyzed with antibodies against CA II, CA VII, CA IX, and CA XII. Intensity and extent of staining were both scored from 0 to 3 in each sample. These enzyme expression levels were then correlated to patients’ survival and clinicopathological parameters, which were tumor differentiation grade and stage, site of tumor, patients’ age, and gender. Kaplan-Meier analysis and Cox regression hazard ratio model were used to analyze survival data. RESULTS CA II and CA XII staining intensities correlated with patients’ survival in that higher expression indicated poorer prognosis. In Cox regression analysis one unit increase in the CA II intensity increased the hazard ratio to 1.19 fold (CI: 1.04-1.37, P = 0.009). A significant correlation was also found when comparing CA XII staining intensity with survival of CRC patients (HR = 1.18, 95%CI: 1.01-1.38, P = 0.036). The extent of CA XII immunostaining did not correlate to the patients’ survival (P = 0.242, Kaplan-Meier analysis). A significant interaction between age group and extent of the CA II staining was found. Increased extent of CA II had a significant hazard ratio among patients 65 years and older (1.42, 95%CI: 1.16-1.73, P = 0.0006). No correlations were found between CA VII (intensity P = 0.566, extent P = 0.495, Kaplan-Meier analysis), or CA IX (intensity P = 0.879, extent P = 0.315, Kaplan-Meier analysis) immunostaining results and survival, or the other parameters. CONCLUSION The present findings indicate that CA II and CA XII could be useful in predicting survival in CRC.

REG4 independently predicts better prognosis in non-mucinous colorectal cancer.

Introduction Colorectal cancer (CRC) is one of the world’s three most common cancers and its incidence is rising. To identify patients who benefit from adjuvant therapy requires novel biomarkers. The regenerating islet-derived gene (REG) 4 belongs to a group of small secretory proteins involved in cell proliferation and regeneration. Its up-regulated expression occurs in inflammatory bowel diseases also in gastrointestinal cancers. Reports on the association of REG4 expression with CRC prognosis have been mixed. Our aim was to investigate tumor REG4 expression in CRC patients and its coexpression with other intestinal markers. Methods Tumor expression of REG4 was evaluated by immunohistochemistry in 840 consecutive surgically treated CRC patients at Helsinki University Central Hospital. Expression of MUC1, MUC2, MUC5AC, synapthophysin, and chromogranin was evaluated in a subgroup of 220 consecutively operated CRC patients. REG4 expression with clinicopathological parameters, other intestinal markers, and the impact of REG4 expression on survival were assessed. Results REG4 expression associated with favorable clinicopathological parameters and with higher overall survival from non-mucinous CRC (p = 0.019). For such patients under 65, its expression was an independent marker of lower risk of death within 5 years that cancer; univariable hazard ratio (HR) = 0.57; 95% confidence interval (CI) (0.34–0.94); multivariable HR = 0.55; 95% CI (0.33–0.92). In non-mucinous CRC, REG4 associated with positive MUC2, MUC4, and MUC5AC expression. Conclusion We show, to our knowledge for the first time, that REG4 IHC expression to be an independent marker of favorable prognosis in non-mucinous CRC. Our results contradict those from studies based on quantification of REG4 mRNA levels, a discrepancy warranting further studies.

Retrotransposon insertions can initiate colorectal cancer and are associated with poor survival

Genomic instability pathways in colorectal cancer (CRC) have been extensively studied, but the role of retrotransposition in colorectal carcinogenesis remains poorly understood. Although retrotransposons are usually repressed, they become active in several human cancers, in particular those of the gastrointestinal tract. Here we characterize retrotransposon insertions in 202 colorectal tumor whole genomes and investigate their associations with molecular and clinical characteristics. We found highly variable retrotransposon activity among tumors and identified recurrent insertions in 15 known cancer genes. In approximately 1% of the cases we identified insertions in APC, likely to be tumor-initiating events. Insertions were positively associated with the CpG island methylator phenotype and the genomic fraction of allelic imbalance. Clinically, high number of insertions was independently associated with poor disease-specific survival.

Comprehensive evaluation of coding region point mutations in microsatellite-unstable colorectal cancer

Microsatellite instability (MSI) leads to accumulation of an excessive number of mutations in the genome, mostly small insertions and deletions. MSI colorectal cancers (CRCs), however, also contain more point mutations than microsatellite‐stable (MSS) tumors, yet they have not been as comprehensively studied. To identify candidate driver genes affected by point mutations in MSI CRC, we ranked genes based on mutation significance while correcting for replication timing and gene expression utilizing an algorithm, MutSigCV. Somatic point mutation data from the exome kit‐targeted area from 24 exome‐sequenced sporadic MSI CRCs and respective normals, and 12 whole‐genome‐sequenced sporadic MSI CRCs and respective normals were utilized. The top 73 genes were validated in 93 additional MSI CRCs. The MutSigCV ranking identified several well‐established MSI CRC driver genes and provided additional evidence for previously proposed CRC candidate genes as well as shortlisted genes that have to our knowledge not been linked to CRC before. Two genes, SMARCB1 and STK38L, were also functionally scrutinized, providing evidence of a tumorigenic role, for SMARCB1 mutations in particular.