The influence of metastatic site on the expression of CEA and cellular localization of β-catenin in colorectal cancer

Identification and prognostic analysis of candidate biomarkers for lung metastasis in colorectal cancer

Colorectal cancer (CRC) is one of the most prevalent types of malignant tumors. It's vital to explore new biomarkers and potential therapeutic targets in CRC lung metastasis through adopting integrated bioinformatics tools. Multiple cohort datasets and databases were integrated to clarify and verify potential key candidate biomarkers and signal transduction pathways in CRC lung metastasis. DAVID, STRING, UALCAN, GEPIA, TIMER, cBioPortal, THE HUMAN PROTEIN ATLAS, GSEA 4.3.2, FUNRICH 3.1.3, and R 4.2.3 were utilized in this study. The enriched biological processes and pathways modulated by the differentially expressed genes (DEGs) were determined with Gene Ontology, Kyoto Encyclopedia of Genes and Genomes. The search tool Retrieval of Interacting Genes and Cytoscape were used to construct a protein-protein interaction network among DEGs. Four hundred fifty-nine colorectal primary cancer and lung metastatic gene expression profiles were screened from 3 gene expression profiles (GSE41258, GSE68468, and GSE41568). Forty-one upregulated genes and 8 downregulated genes were identified from these 3 gene expression profiles and verified by the transcriptional levels of hub genes in other GEO datasets and The Cancer Genome Atlas database. Two pathways (immune responses and chemokine receptors bind chemokines), 13 key DEGs, 6 hub genes (MMP3, SFTPD, ABCA3, CLU, APOE, and SPP1), and 2 biomarkers (APOE, SPP1) with significantly prognostic values were screened. Forty-nine DEGs were identified as potential candidate diagnostic biomarkers for patients with CRC lung metastasis in present study. Enrichment analysis indicated that immune responses and chemokine receptors bind chemokines may play a leading role in lung metastasis of CRC, and further studies are needed to validate these findings.

Identification of hub genes and pathways in lung metastatic colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is one of the most prevalent types of malignant tumours. Metastasis is the leading cause of cancer-related mortality, with lung metastases accounting for 32.9% of all metastatic CRCs. However, since the biological mechanism of lung metastatic CRC is poorly understood, limited therapeutic targets are available. In the present study, we aimed to identify the key genes and molecular processes involved in CRC lung metastasis.

METHODS

The differentially expressed genes (DEGs) between primary and lung metastatic CRC patients were obtained from the Gene Expression Omnibus (GEO) database via the GEO2R tool. The enriched biological processes and pathways modulated by the DEGs were determined with Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Reactome Gene Sets analyses. The search tool Retrieval of Interacting Genes (STRING) and Cytoscape were used to construct a protein-protein interaction (PPI) network among DEGs.

RESULTS

The DEGs were enriched in surfactant metabolism, cell-cell communication and chemokine signaling pathways. The defined hub genes were included CLU, SFTPD, CCL18, SPP1, APOE, BGN and MMP3. Among them, CLU, SFTPD and CCL18 might be associated with the specific lung tropism metastasis in CRC. In addition, the expression and prognostic values of the hub genes in CRC patients were verified in database of The Cancer Genome Atlas (TCGA) and GEO. Moreover, the protein levels of the hub genes were detected in primary and lung metastatic CRC cells, serum or tissues. Furthermore, SFTPD was confirmed to facilitate cellular proliferation and lung metastasis in CRC.

CONCLUSION

This bioinformatics study may provide a better understanding of the candidate therapeutic targets and molecular mechanisms for CRC lung metastasis.

High-Precision Quantitative Analysis Reveals Carcinoembryonic Protein Expression Differs Among Colorectal Cancer Primary Foci and Metastases to Different Sites

The expression of carcinoembryonic protein (CEA) is an important biological marker and therapeutic target in colorectal cancer (CRC). CEA expression heterogeneity confers resistance to CEA-targeting immunotherapy antibodies. Thus, quantification of the CEA-positive cell ratio among all tumor cells would be important in identifying patients that would benefit from CEA-targeted therapies. However, the proportion of tumor cells that express CEA within primary and metastasized tumors at different sites has not been studied. Therefore, the present study aimed to determine CEA positive cell proportion in paired CRC primary foci, liver metastases, and lymph node (LN) metastases, and whether proportion of CEA positive cell differs among colorectal cancer primary foci, liver metastases, and LN metastases from 26 patients. The CEA expression was detected by immunohistochemical assay. Then we set up a quantification approach to quantify the proportion of CEA-positive cells based on the TissueGnostics (TG) system. Then the proportion of CEA positive cells were measured and compared among primary foci, liver metastases, and LN metastases. As a result, the proportion of CEA positive tumor cells was slightly higher in liver metastases than in primary foci (89.8% ± 2.71% vs 82.1% ± 5.05%, P < 0.001). The proportion of CEA-positive cells was significantly lower in LN metastases than in primary foci (82.3% ± 4.32% vs 70.28% ± 5.04%, P < 0.001). In 8 cases with matched CRC primary foci, liver metastases, and LN metastases, the proportions of CEA proportion in liver metastasis was the highest, followed by primary foci and LNs metastasis. In conclusion, this study provided an new approach for quantification of CEA positive cell in tumors and proved the percentage of CEA-positive cells varied in different metastases.

Carcinoembryonic antigen reduction after medical treatment in patients with metastatic colorectal cancer: a systematic review and meta-analysis

PURPOSE

The introduction of new drugs and multimodal treatments for the management of patients with metastatic colorectal cancer (mCRC) has reduced the importance of time-to-event endpoints and reported the attention on the response-related endpoints. Furthermore, the prognostic role of the surgical scores before the resection of metastases has not been confirmed for multimodal treatments. The purpose of this research is to perform a meta-analysis of the studies that evaluated the relationship between carcinoembryonic antigen (CEA) response and outcome in patients with mCRC receiving systemic chemotherapy.

METHODS

A systematic review of the literature on two databases and a selection of studies that evaluated the relationship between CEA response and outcome were performed according to predefined criteria. After, three meta-analyses were carried out on the selected studies, each for each outcome variable.

RESULTS

Nineteen studies have been selected. Fourteen studies (1475 patients) have documented a close association between radiological response and CEA response (odds ratio (OR), 9.03; confidence intervals (CIs), 5.14-15.87; I² statistic (I²), 72%). Four studies have reported a longer progression-free survival for patients with a CEA response (hazard ratio (HR), 0.73; CIs, 0.64-0.83; I², 23%). Finally, 10 studies (13 study cohorts) have shown a strong relationship between CEA response and overall survival (OS) (HR, 0. 62; CIs, 0.55-0.70; I², 35%).

CONCLUSIONS

CEA response merits further investigation as a surrogate endpoint of clinical trials of first-line medical therapy of patients with mCRC, and should be studied as a prognostic factor for those patients who are candidates for multimodal treatment strategies.

A 6-week laboratory research rotation in pharmacogenomics: a model for preparing pharmacy students to practice precision medicine

Comparison of human genome sequences from different individuals has unraveled that genes involved in the drug efficacy and metabolism are polymorphic, harboring mutations, splicing variations and other alterations. These data provide a reasonable explanation for the inter-individual variations observed in drug therapy. Thus, a detailed molecular analysis and an in-depth knowledge of these genes is a prerequisite to practice pharmacogenomics-based medicine. We have introduced a 6-week laboratory research rotation to train students in the expression analysis of different pharmacogenes combined with bioinformatics tools. Students were first introduced to the bioinformatics tools to identify appropriate DNA primers to amplify specific pharmacogenes from the laboratory cancer cell lines. The amplified DNA fragments were sequenced. Finally, students were trained in bioinformatics tools to establish the identity of these DNA sequences. The possible implications of this laboratory training in developing problem-solving skills needed in the implementation of pharmacogenomics knowledge in the clinic, are discussed.

A multimeric carcinoembryonic antigen signal inhibits the activation of human T cells by a SHP-independent mechanism: a potential mechanism for tumor-mediated suppression of T-cell immunity

Carcinoembryonic antigen (CEA) is a well-known tumor antigen that is found in the serum of patients with various cancers and is correlated with an increased risk of cancer recurrence and metastasis. To understand the tumor environment and to develop antitumor therapies, CEA has been studied as an antigen to activate/tolerate specific T cells. In this study, we show that CEA can function as a coinhibitory molecule and can inhibit the activation of human peripheral blood mononucleated cell-derived T cells. The addition of CEA-overexpressing tumor cells or immobilized CEA dampened both cell proliferation and the expression of IL-2 and CD69 expression in T cells after TCR stimulation. The phosphorylation of ERK and translocation of NFAT were hampered in these cells, whereas the phosphorylation of proximal TCR signaling molecules such as ZAP70 and phospholipase Cγ was not affected by immobilized CEA. To determine the relevance of carcinoembryonic antigen-related cell adhesion molecule-1 and Src homology region 2 domain-containing phosphatase (SHP) molecules to CEA-mediated suppression, we tested the effect of the SHP inhibitor, NSC-87877, on CEA-mediated suppression of T cells; however, it did not reverse the effect of CEA. Collectively, these results indicate that CEA can function as a modulator of T-cell responses suggesting a novel mechanism of tumor evasion.

Feasibility of mesorectal vascular invasion in predicting early distant metastasis in patients with stage T3 rectal cancer based on rectal MRI

OBJECTIVES

To evaluate the feasibility of mesorectal vascular invasion (MVI) in predicting early distant metastasis developed within 1 year of diagnosis of T3 rectal cancer using magnetic resonance imaging (MRI) METHODS: Sixty-five patients with T3 rectal cancer (early metastasis, n = 28; non-metastasis, n = 37) were enrolled in this study. Early distant metastases developed in 28 patients (liver, n = 15; lung, n = 9; both, n = 4). Logistic regression was used to determine the independent predictors for early distant metastasis.

RESULTS

In univariate analysis, tumour location, carcinoembryonic antigen (CEA), lymphovascular invasion (LVI), MRI-detected MVI, and mesorectal fat infiltration (MFI) (odds ratio [OR], 4.533, 9.583, 5.539, 27.046, and 5.539, respectively) were associated with early distant metastasis. Multivariate analysis demonstrated that MVI (OR, 29.949; P < 0.002) and LVI (OR, 6.684; P = 0.033) were independent factors for early distant metastasis. Specificity and positive predictive value (PPV) of MVI (94.59%, and 89.47%, respectively) were significantly higher than those of LVI (64.86%, and 61.76%), but sensitivity and negative predictive value were not significantly different between MVI (60.71%, and 76.09%) and LVI (75.00%, and 77.42%).

CONCLUSIONS

While sensitivity of MRI-detected MVI was equal to that of CEA in predicting early distant metastasis from T3 rectal cancer, specificity and PPV may be improved by assessing MVI.

KEY POINTS

• Mesorectal vascular invasion (MVI) may be a radiologic prognostic factor for rectal cancer. • Specificity of MVI was higher than lymphovascular invasion in predicting early metastasis. • Mesorectal vascular invasion may be a better predictor for early distant metastasis.

Heterogeneity in the expression of receptors in the human breast cancer metastasized to the brain

Assessment of the human epidermal growth factor receptor-2 (Her2/ErbB2) and estrogen receptor (ER) and progesterone receptor (PR) expression in breast cancer has been an accepted standard to predict clinical outcome. Expression of these receptors in primary breast cancer has also been an important predictor of visceral organ metastasis. Many studies of breast cancer have reported risk factors for brain metastasis that include Her2/ErbB2 positivity, ER negativity, and negativity for all the above three receptors. However, it is not clear whether expression of these receptors would persist subsequent to brain metastasis. To address this possibility, we analyzed different breast cancer brain metastases (BCBM) for the expression of Her2/ErbB2, ER, and PR by immunohistochemistry procedure. The results showed that BCBM are heterogeneous in the receptor expression: Five BCBMs were Her2/ErbB2-positive and one negative; four BCBMs were ER-positive, and two were negative; five BCBMs were PR-positive and one negative. However, expression of these receptors in their combination is also heterogeneous: Four BCBMs were positive for all of the Her2/ErbB2, ER, and PR; one BCBM was positive for Her2/ErbB2 and PR but negative for ER; one BCBM was positive for PR but negative for Her2/ErbB2/ER. Similar heterogeneity in the expression of these receptors was also observed in primary tumors. Importantly, BCBM tumors that were assigned as ER- and PR-positive contained tumor cells that lacked expression of these receptors in other regions of the biopsies. Taken together, our findings indicate that the BCBM exhibit heterogeneity in the expression amounts of Her2/ErbB2, ER, and PR, which could be a result of the influence of tumor microenvironment in the brain or different tumor cells populating the metastatic region.

Factors predicting long-term survival in colorectal cancer patients with a normal preoperative serum level of carcinoembryonic antigen

PURPOSE

The aim of this study was to determine which clinicopathological factors influenced the long-term survival after potentially curative resection of colorectal cancer patients with a normal preoperative serum level of carcinoembryonic antigen (CEA).

METHODS

A total of 1,732 patients who underwent curative surgery for primary nonmetastatic colorectal cancers from 1997 to 2009 were analyzed. Of these patients, 1,128 (65.1 %) had normal level of preoperative CEA (<5 ng/mL). The predicting factors for survival were analyzed.

RESULTS

When the serum CEA cutoff value was set at 2.4 ng/mL (median value), the high CEA groups displayed a higher percentage of older patients, males, large-diameter tumors, advanced T and N categories, and positive perineural invasion, compared to the low CEA groups. Multivariate analysis revealed that age, T category, N category, number of lymph nodes retrieved, operative method, lymphovascular invasion, perineural invasion, postoperative chemotherapy, and preoperative serum CEA level ≥ 2.4 ng/mL were independent predictors for 5-year overall survival, while tumor location, tumor size, T category, N category, lymphovascular invasion, and perineural invasion were independent predictors for 5-year disease-free survival.

CONCLUSIONS

Even if patients with colorectal cancer have a normal preoperative CEA before surgery, CEA may be useful for prognostic stratification using 2.4 ng/mL as the cutoff.