Expression of EGF, EGF-receptor, p53, v-erb B and ras p21 in colorectal neoplasms by immunostaining paraffin-embedded tissues

Recommendations for Specimen and Therapy Selection in Colorectal Cancer

INTRODUCTION

Next-generation sequencing has emerged as a clinical tool for the identification of actionable mutations to triage advanced colorectal cancer patients for targeted therapies. The literature is conflicted as to whether primaries or their metastases should be selected for sequencing. Some authors suggest that either site may be sequenced, whereas others recommend sequencing the primary, the metastasis, or even both tumors. Here, we address this issue head on with a meta-analysis and provide for the first time a set of sensible recommendations to make this determination.

METHODS

From our own series, we include 43 tumors from 13 patients including 14 primaries, 10 regional lymph node metastases, 17 distant metastases, and two anastomotic recurrences sequenced using the 50 gene Ion AmpliSeq cancer NGS panel v2.

RESULTS

Based on our new cohort and a meta-analysis, we found that ~ 77% of patient-matched primary-metastatic pairs have identical alterations in these 50 cancer-associated genes.

CONCLUSIONS

Low tumor cellularity, tumor heterogeneity, clonal evolution, treatment status, sample quality, and/or size of the sequencing panel accounted for a proportion of the differential detection of mutations at primary and metastatic sites. The therapeutic implications of the most frequently discordant alterations (TP53, APC, PIK3CA, and SMAD4) are discussed. Our meta-analysis indicates that a subset of patients who fail initial therapy may benefit from sequencing of additional sites to identify new actionable genomic abnormalities not present in the initial analysis. Evidence-based recommendations are proposed.

Functions and regulation of MUC13 mucin in colon cancer cells

BACKGROUND

MUC13 is overexpressed and aberrantly localized in colon cancer tissue; however, the specific functions and regulation of MUC13 expression are unknown.

METHODS

Stable cell lines with either overexpressed or suppressed MUC13 levels were analyzed to determine cell growth, colony formation, cell migration, and cell invasion assays. The molecular mechanisms involved in MUC13 regulation were elucidated via chromatin immunoprecipitation (ChIP) and analysis of interleukin 6 (IL6) treatments. Colon cancer tissues were analyzed by immunohistochemistry (IHC) for the protein levels of MUC13 and P-STAT5 in colon cancer cells.

RESULTS

Overexpression of MUC13 increased cell growth, colony formation, cell migration, and invasion. In concordance, MUC13 silencing decreased these tumorigenic features. Overexpression of MUC13 also modulated various cancer-associated proteins, including telomerase reverse transcriptase, sonic hedgehog, B cell lymphoma murine like site 1, and GATA like transcription factor 1. Additionally, MUC13-overexpressing cells showed increased HER2 and P-ERK expression. ChIP analysis revealed binding of STAT5 to the predicted MUC13 promoter. IL6 treatment of colon cancer cells increased the expression of MUC13 via activation of the JAK2/STAT5 signaling pathway. Suppression of JAK2 and STAT5 signaling by chemical inhibitors abolished IL6-induced MUC13 expression. IHC analysis showed increased expression of both P-STAT5 and MUC13 in colon cancer as compared to adjacent normal tissue.

CONCLUSIONS

The results of this study, for the first time, suggest functional roles of MUC13 in colon cancer progression and provide information regarding the regulation of MUC13 expression via JAK2/STAT5 which may reveal promising therapeutic approaches for colon cancer treatment.

Epidermal growth factor receptor (EGFR) gene copy number in colorectal adenoma-carcinoma progression

Adenomas are the easily identifiable precursors of the vast majority of colorectal cancers. Some of their morphological features, such as dysplasia, are predictive of their biological evolution toward adenocarcinomas. A large body of evidence has demonstrated that the epidermal growth factor receptor (EGFR) signaling pathway is commonly activated in colorectal cancer and EGFR-target therapies have improved the outcome for colorectal cancer patients. Nevertheless, the mechanisms underlying the role of EGFR in the adenoma-carcinoma sequence are not entirely clear. We retrospectively analyzed EGFR gene copy number by fluorescence in situ hybridization (FISH) in paraffin-embedded tissue from 215 patients recruited through a prospective colorectal cancer screening procedure and undergoing surgical colectomy. We observed that in human colorectal carcinogenesis, EGFR copy number increases progressively, from adenomas with high-grade dysplasia to locally advanced adenocarcinomas, through early invasive adenocarcinomas, suggesting that deregulation of EGFR may correlate with the malignant progression.

The Crosstalk of PTGS2 and EGF Signaling Pathways in Colorectal Cancer

Colorectal cancer (CRC) is now the second-leading cause of cancer deaths in the USA. Colorectal cancer progression and metastasis depends on the orchestration of the aberrant signaling pathways that control tumor cell proliferation, survival and migration/invasion. Epidemiological, clinical, and animal studies have demonstrated that prostaglandin-endoperoxide synthase 2 (PTGS2) and epithelial growth factor (EGF) signaling pathways play key roles in promoting colorectal cancer growth and metastasis. In this review, we highlight major advances in our understanding of the roles of PTGS2 and EGF signaling in colorectal cancer.

Targeting the HER2 pathway for the therapy of lower esophageal and gastric adenocarcinoma

INTRODUCTION

The mysteries of complex molecular pathways of tumorigenesis are only beginning to be unraveled. Overexpression of HER2 receptors has been associated with adverse outcomes in certain malignant solid tumors.

AREAS COVERED

The authors give a focused review of the HER2 pathway and its importance for cancer cell survival. Similar to the situation in breast cancer, HER2 overexpression is seen in up to one-quarter of all gastric and gastroesophageal junction adenocarcinomas. The audience will also be familiarized with the existing HER2 targeted agents (both at the bench and at the bedside) for the therapy of gastric and gastroesophageal cancers.

EXPERT OPINION

Despite recent advances, treatment of upper gastrointestinal malignancies remains a significant challenge. Trastuzumab in combination with chemotherapy is the current standard of therapy for patients with metastatic HER2-overexpressing esophageal and gastric cancers. The activity of lapatinib, an active agent in advanced HER2-positive breast cancer, is now being tested in HER2-overexpressing esophageal and gastric adenocarcinomas. A variety of monoclonal antibodies and tyrosine kinase inhibitors with affinity for HER2 are in development and may improve further the outcomes of these malignancies.

Expression of nucleostemin, epidermal growth factor and epidermal growth factor receptor in human esophageal squamous cell carcinoma tissues

OBJECTIVE

To determine the expression of nucleostemin (NS), epidermal growth factor (EGF) and epidermal growth factor receptor (EGFR) mRNA in human esophageal squamous cell carcinoma (ESCC) tissues and their association in a human ESCC cell line.

METHODS

The expression of NS, EGF and EGFR mRNA was determined in paired normal esophageal and ESCC tissues of 62 patients using in situ hybridization. The association between NS and EGF or EGFR was examined using immunoblotting and real time polymerase chain reaction in a human ESCC cell line transfected with NS siRNA or treated with a selective EGFR inhibitor.

RESULTS

In normal esophageal and ESCC tissues, the positive detection rates were 21.0% (13/62) and 69.4% (43/62) for NS mRNA staining, 40.3% (25/62) and 77.4% (48/62) for EGF mRNA staining, and 30.6% (19/62) and 75.8% (41/62) for EGFR mRNA staining, respectively. These results indicated that NS, EGF and EGFR mRNA expression was upregulated mostly in ESCC tissues. Moreover, the expression of NS, EGF and EGFR mRNA was positively correlated with tumor grade, invasion and lymphatic metastasis of ESCC cells. NS mRNA was co-expressed with EGF and EGFR mRNA in ESCC tissues. The in vitro studies using a human ESCC cell line showed that knockdown of NS with NS siRNA significantly reduced EGF and EGFR expression. However, inhibition of the EGFR kinase activity with a specific EGFR kinase inhibitor had minimal effect on NS expression.

CONCLUSION

The upregulation of NS, EGF and EGFR mRNA frequently occurs in ESCC tissues and is associated with malignancy of human esophageal squamous tumors. NS is required for EGF and EGFR expression.

Targeting EGFR and HER-2 with cetuximab- and trastuzumab-mediated immunotherapy in oesophageal squamous cell carcinoma

We previously reported that oesophageal squamous cell carcinoma (SCC) had a relatively high incidence of EGFR and HER-2 overexpression. Thus, anti-HER family targeting may become a promising approach to treat oesophageal SCC. In the present study, we investigated (a) the distribution of EGFR and HER-2 expression in oesophageal SCC (n=66) detected by immunohistochemistry and (b) cetuximab- and/or trastuzumab-mediated biological activity (antiproliferative effect by the MTT assay, apoptosis-inducing activity by the annexin V/propidium iodide assay, and antibody-dependent cellular cytotoxicity (ADCC) by the ⁵¹Cr-release assay) against oesophageal SCC cell lines with various levels of EGFR and HER-2. Twelve of the 66 patients (18%) showed both EGFR- and HER-2 expression. Out of both EGFR- and HER-2-positive cases, nine cases (75%) showed EGFR and HER-2 expression in individually distinct regions. Furthermore, the combination of cetuximab and trastuzumab could induce synergistic antiproliferative effects and additional ADCC activities against not all, but several oesophageal SCC cell lines with EGFR and HER-2 expression. The combination of cetuximab and trastuzumab may be useful in the treatment of oesophageal SCC with EGFR and HER-2 expression.

The epidermal growth factor receptor as a target for colorectal cancer therapy

The epidermal growth factor receptor (EGFR) is the prototypical member of the erbB receptor family. The EGFR axis is activated by a variety of ligands that are crucial in the formation and propagation of many tumors, including colorectal cancer, through their effects on cell signaling pathways, cellular proliferation, control of apoptosis, and angiogenesis. The importance of the EGFR axis in tumorigenesis and tumor progression makes it an attractive target for the development of anticancer therapies. A variety of targeting strategies to exploit the role of EGFR in tumors have been employed. The most highly developed of these anti-EGFR approaches are the monoclonal antibodies and the tyrosine kinase inhibitors (TKIs). Clinical evaluations of these compounds have yielded some promising results. The role of the EGFR axis in colorectal cancer formation and progression is reviewed and the clinical development of these anticancer EGFR-targeted drugs is reviewed and updated.

Nicotine promoted colon cancer growth via epidermal growth factor receptor, c-Src, and 5-lipoxygenase-mediated signal pathway

Nicotine [3-(1-methyl-2-pyrrolidinyl)-pyridine], a major alkaloid in tobacco, has been implicated as playing a role in carcinogenesis. Our previous study showed that passive cigarette smoking promoted inflammation-associated colonic adenoma formation in mice, and 5-lipoxygenase (5-LOX) plays an important role in this process. In the present study, we aimed to investigate whether nicotine could stimulate colon cancer cell proliferation and tumor growth in nude mice xenograft model and the possible mechanisms involved. Results showed that nicotine stimulated SW1116 colon cancer cell proliferation in a dose-dependent manner. Epidermal growth factor receptor (EGFR) and c-Src phosphorylation levels together with protein expression of 5-LOX were also significantly enhanced in this proliferation process. Inhibitors of EGFR and c-Src alleviated the actions of nicotine on cell proliferation and 5-LOX protein expression. Combination of both agents produced additive effect. In contrast, 5-LOX inhibitor had no direct effect on the phosphorylation levels of EGFR and c-Src and yet inhibited cell proliferation. In the colon cancer xenograft model, nicotine also significantly enhanced tumor growth. This acceleration of tumor growth corresponded well with increased vascularization and its proangiogenic factors. Inhibitors of EGFR, c-Src, and 5-LOX all significantly impeded the tumor growth induced by nicotine. Together, nicotine can promote colonic tumorigenesis both in vitro and in vivo. Activation of the phosphorylated form of EGFR and c-Src followed by an increased 5-LOX expression are the prime pathogenic mechanisms in the tumorigenic process in the colon.

Importance of epidermal growth factor receptor signaling in establishment of adenomas and maintenance of carcinomas during intestinal tumorigenesis

We used the hypomorphic Egfr(wa2) allele to genetically examine the impact of impaired epidermal growth factor receptor (Egfr) signaling on the Apc(Min) mouse model of familial adenomatous polyposis. Transfer of the Apc(Min) allele onto a homozygous Egfr(wa2) background results in a 90% reduction in intestinal polyp number relative to Apc(Min) mice carrying a wild-type Egfr allele. This Egfr effect is potentially synergistic with the actions of the modifier-of-min (Mom1) locus. Surprisingly, the size, expansion, and pathological progression of the polyps appear Egfr-independent. Histological examination of the ilea of younger animals revealed no differences in the number of microadenomas, the presumptive precursor lesions to gross intestinal polyps. Pharmacological inhibition with EKI-785, an Egfr tyrosine kinase inhibitor, produced similar results in the Apc(Min) model. These data suggest that normal Egfr activity is required for establishment of intestinal tumors in the Apc(Min) model between initiation and subsequent expansion of initiated tumors. The role of Egfr signaling during later stages of tumorigenesis was examined by using nude mice xenografts of two human colorectal cancer cell lines. Treatment with EKI-785 produced a dose-dependent reduction in tumor growth, suggesting that Egfr inhibitors may be useful for advanced colorectal cancer treatment.

Epidermal growth factor receptor immunohistochemical reactivity in patients with American Joint Committee on Cancer Stage IV colon adenocarcinoma: implications for a standardized scoring system

BACKGROUND

An epidermal growth factor receptor (EGFR) immunohistochemical detection system currently is being developed. The current study attempts to address background EGFR reactivity issues before determining the optimum EGFR scoring system.

METHODS

Tissue sections from 102 patients with T3N1-2M1 colon adenocarcinoma were stained with a prototype EGFR detection system. The number of cases, location, percentage, and intensity of reactive cells (0+ [none] to 3+ [strong]) were scored and compared with the length of survival.

RESULTS

Approximately 75.5% of the adenocarcinoma cases had EGFR reactivity; 31.4% of the tumors had 3+ reactivity in 10-50% of the neoplastic cells and 3.9% had 3+ reactivity in > 50% of cells. Increased numbers of reactive cells per case predominantly resulted from increased 3+ reactivity. The mean percentage of 2+ (moderate) and 3+ reactive cells per case increased in the regions of deepest invasion. The mean percentage of 3+ reactivity per case was significantly greater in the deepest tumor region compared with the superficial region (16.9% vs. 7.9%; P = 0.004). EGFR reactivity in metastases appeared to have the strongest correlation with reactivity in the deep regions of colon adenocarcinoma. An increasing percentage of 2+ and 3+ or 3+ only reactivity in the deep region was found to have the strongest correlation with decreased survival (P = 0.0252).

CONCLUSIONS

EGFR reactivity of 2+ and 3+ may provide a framework for a scoring system. It may be important to evaluate EGFR reactivity in the deepest region of tumor invasion because this region appears to contain the largest percentage of 3+ reactive cells and appears to have the strongest correlation with survival length and EGFR reactivity in lymph node and liver metastases.

Epidermal growth factor receptor immunohistochemical reactivity in patients with American Joint Committee on Cancer Stage IV colon adenocarcinoma: implications for a standardized scoring system

BACKGROUND

An epidermal growth factor receptor (EGFR) immunohistochemical detection system currently is being developed. The current study attempts to address background EGFR reactivity issues before determining the optimum EGFR scoring system.

METHODS

Tissue sections from 102 patients with T3N1-2M1 colon adenocarcinoma were stained with a prototype EGFR detection system. The number of cases, location, percentage, and intensity of reactive cells (0+ [none] to 3+ [strong]) were scored and compared with the length of survival.

RESULTS

Approximately 75.5% of the adenocarcinoma cases had EGFR reactivity; 31.4% of the tumors had 3+ reactivity in 10-50% of the neoplastic cells and 3.9% had 3+ reactivity in > 50% of cells. Increased numbers of reactive cells per case predominantly resulted from increased 3+ reactivity. The mean percentage of 2+ (moderate) and 3+ reactive cells per case increased in the regions of deepest invasion. The mean percentage of 3+ reactivity per case was significantly greater in the deepest tumor region compared with the superficial region (16.9% vs. 7.9%; P = 0.004). EGFR reactivity in metastases appeared to have the strongest correlation with reactivity in the deep regions of colon adenocarcinoma. An increasing percentage of 2+ and 3+ or 3+ only reactivity in the deep region was found to have the strongest correlation with decreased survival (P = 0.0252).

CONCLUSIONS

EGFR reactivity of 2+ and 3+ may provide a framework for a scoring system. It may be important to evaluate EGFR reactivity in the deepest region of tumor invasion because this region appears to contain the largest percentage of 3+ reactive cells and appears to have the strongest correlation with survival length and EGFR reactivity in lymph node and liver metastases.

Epidermal growth factor induces expression of decay-accelerating factor in human colonic cancer cells via the mitogen-activated protein kinase pathway

The expression of decay-accelerating factor (DAF), a complement regulatory protein, is enhanced in colorectal cancer. In this study, to elucidate mechanisms for enhanced DAF expression, we studied the effects of growth factors on DAF expression in HT-29 human colonic cancer cells. Cells were treated with epidermal growth factor (EGF), insulin-like growth factor-I, platelet-derived growth factor, and transforming growth factor-beta. DAF protein expression and mRNA expression were determined with enzyme immunoassay and Northern blot analysis. The signaling pathways that target DAF expression in response to growth factor stimulation were characterized by using various inhibitors of the signal transduction pathway. EGF induced significant increases in DAF protein and mRNA expression in HT-29 cells; the other growth factors had a weak effect or no effect. The EGF-induced DAF expression was inhibited by mitogen-activated protein (MAP) kinase kinase inhibitor PD 98059 but not by phosphatidylinositol-3 kinase inhibitor, phospholipase Cgamma inhibitor, or protein kinase C inhibitor. When we analyzed the phosphorylation state of the MAP kinase by immunoblot analysis, phosphorylated p44/p42 MAP kinase was detected in EGF-stimulated HT-29 cells, and the addition of PD 98059 abrogated the phosphorylation. These results indicate that EGF regulates DAF expression in HT-29 cells via the signaling pathway that depends on the activation of MAP kinase.

Cell surface molecules and their prognostic values in assessing colorectal carcinomas

OBJECTIVE

Carcinomas of the colon and rectum are the third leading cause of cancer-related deaths. Although advances in the surgical treatment of primary colorectal cancers have lead to improvements in patient survival at early tumor stages, treatment of more progressive cancers has not resulted in dramatic improvements in patient survival. However, the selection of patient subgroups based on their prognosis and other characteristics could result in improved outcomes from adjuvant therapies in patients with Dukes B and C carcinomas.

METHODS

The authors reviewed the available data on the value of cell surface molecules in assessing the prognosis of colorectal carcinomas, paying specific attention to the evaluation of statistical analysis and multivariate procedures.

RESULTS

Cell surface molecules have been identified on colorectal carcinoma cells whose expression appears to be related to malignant transformation, tumor progression, or patient prognosis. Among these cell surface molecules, various cell adhesion molecules, growth factor receptors, proteinases, and their receptors and inhibitors have been identified as potentially useful prognostic markers.

CONCLUSIONS

Although data exist on the prognostic values of certain cell surface markers, the use of multivariate analysis for the identification of valuable prognostic factors remains uncommon. Using reproducible and standardized multivariate analysis procedures, new tumor markers should be carefully examined for their biologic and prognostic relevance before being considered as potentially useful in the management of colorectal cancers.

Simultaneous expression of the ras p21 and p53 proteins in human endometrial carcinomas

The expression of ras-encoded p21 and p53 proteins was analyzed by immunohistochemical staining with monoclonal antibodies in 26 paraffin-embedded specimens (25 endometrial carcinomas and 1 uterine carcinosarcoma) taken from Polish women. The biotin-streptavidin-peroxidase detection system was employed. ras p21 protein was expressed in 68% of the specimens and p53 positive staining was noted in 36% of the carcinomas. Simultaneous expression of the ras p21 and p53 proteins was demonstrated in 8 (32%) out of the 25 specimens. Except one case, where the p53 protein was expressed, ras p21 protein was also detected. Both proteins were demonstrated in the sole case of carcinosarcoma. A difference between the detection of simultaneous expression of the ras p21 and p53 proteins in correlation with FIGO stages I to II-IV has been reported (22% v. 57% respectively). These data indicate, that ras p21 correlated with p53 positive staining in one-third of the endometrial cancers analyzed. The simultaneous detection of both proteins correlated with the advanced clinical stage of human endometrial carcinomas.