Assessment of SMAD4, p53, and Ki-67 alterations as a predictor of liver metastasis in human colorectal cancer

Molecular and Immunohistochemical Markers with Prognostic and Predictive Significance in Liver Metastases from Colorectal Carcinoma

Despite the significant recent achievements in the diagnosis and treatment of colorectal cancer (CRC), the prognosis of these patients has currently plateaued. During the past few years, the opportunity to consider multiple treatment modalities (including surgery and other locoregional treatments, systemic therapy, and targeted therapy) led to the research of novel prognostic and predictive biomarkers in CRC liver metastases (CRCLM) patients. In this review, we seek to describe the current state of knowledge of CRCLM biomarkers and to outline impending clinical perspectives, in particular focusing on the cutting-edge tools available for their characterization.

p62/sequestosome 1 in human colorectal carcinoma as a potent prognostic predictor associated with cell proliferation

p62/sequestosome 1 (p62) is a multi-domain protein that functions as a receptor for ubiquitinated targets in the selective autophagy and serves as a scaffold in various signaling cascades. p62 have been reported to be up-regulated in several human malignancies, but the biological roles and significance of p62 are still poorly understood in colorectal carcinoma. We immunohistochemically evaluated p62 in 118 colorectal adenocarcinoma and 28 colorectal adenoma cases. We used four colon carcinoma cells (HCT8, HT29, COLO320, and SW480) in the in vitro studies. p62 immunoreactivity was detected in 11% of colorectal adenoma cases and 31% of adenocarcinoma cases, while it was negligible in the normal epithelium. The immunohistochemical p62 status was significantly associated with synchronous liver metastasis, and it turned out to be an independent adverse prognostic factor in colorectal cancer patients. Following in vitro studies revealed that HCT8 and HT29 cells transfected with p62-specific siRNA showed significantly decreased cell proliferation activity, whereas COLO320 and SW480 cells transfected with p62 expression plasmid showed significantly increased cell proliferation activity. The p62-mediated cell proliferation was not associated with the autophagy activity. These findings suggest that p62 promotes the cell proliferation mainly as a scaffold protein, and that the p62 status is a potent prognostic factor in colorectal carcinoma patients.

Mitochondrial DNA Integrity Is Maintained by APE1 in Carcinogen-Induced Colorectal Cancer

Changes in mitochondrial DNA (mtDNA) integrity have been reported in many cancers; however, the contribution of mtDNA integrity to tumorigenesis is not well understood. We used a transgenic mouse model that is haploinsufficient for the apurinic/apyrimidinic endonuclease 1 (Apex1^+/-) gene, which encodes the base excision repair (BER) enzyme APE1, to determine its role in protecting mtDNA from the effects of azoxymethane (AOM), a carcinogen used to induce colorectal cancer. Repair kinetics of AOM-induced mtDNA damage was evaluated using qPCR after a single AOM dose and a significant induction in mtDNA lesions in colonic crypts from both wild-type (WT) and Apex1^+/-animals were observed. However, Apex1^+/- mice had slower repair kinetics in addition to decreased mtDNA abundance. Tumors were also induced using multiple AOM doses, and both WT and Apex1^+/-animals exhibited significant loss in mtDNA abundance. Surprisingly, no major differences in mtDNA lesions were observed in tumors from WT and Apex1^+/- animals, whereas a significant increase in nuclear DNA lesions was detected in tumors from Apex1^+/- mice. Finally, tumors from Apex1^+/- mice displayed an increased proliferative index and histologic abnormalities. Taken together, these results demonstrate that APE1 is important for preventing changes in mtDNA integrity during AOM-induced colorectal cancer.Implications: AOM, a colorectal cancer carcinogen, generates damage to the mitochondrial genome, and the BER enzyme APE1 is required to maintain its integrity. Mol Cancer Res; 15(7); 831-41. ©2017 AACR.

The Role of Chemokines in Promoting Colorectal Cancer Invasion/Metastasis

Colorectal cancer (CRC) is one of the leading causes of cancer-related death worldwide. Although most of the primary CRC can be removed by surgical resection, advanced tumors sometimes show recurrences in distant organs such as the liver, lung, lymph node, bone or peritoneum even after complete resection of the primary tumors. In these advanced and metastatic CRC, it is the tumor-stroma interaction in the tumor microenvironment that often promotes cancer invasion and/or metastasis through chemokine signaling. The tumor microenvironment contains numerous host cells that may suppress or promote cancer aggressiveness. Several types of host-derived myeloid cells reside in the tumor microenvironment, and the recruitment of them is under the control of chemokine signaling. In this review, we focus on the functions of chemokine signaling that may affect tumor immunity by recruiting several types of bone marrow-derived cells (BMDC) to the tumor microenvironment of CRC.

Analysis of genomic aberrations associated with the clinicopathological parameters of rectal cancer by array‑based comparative genomic hybridization

The aim of the present study was to screen and identify the chromosomal aberrations that are correlated with clinicopathological characteristics of rectal cancer using array-based comparative genomic hybridization (array-CGH). Forty-eight fresh frozen tumor tissues of rectal carcinoma were analyzed by array-CGH. The results showed that most frequent gains included 8q24.3, 20q11.21-q13.32, 20q13.33 and losses in 8p23.3-p12, 17p13.1-p12 and 18q11.2-q23 were noted. Fourteen amplifications and seven homozygous deletions were identified in the rectal cancer samples. Losses of 4p16.1-p15.31, 8p21.1-p12 and gains of 7p12.3-p12.1 and 13q33.1-q34 were associated with positive lymph node status and advanced clinical stage (stages III and IV). The 17q24.2-25.3 gain was more frequent in patients with distant metastasis. Integrated analysis indicated that overexpression of PDP1, TRIB1, C13orf27, FOXA2, PMEPA1 and PHACTR3 was associated with gains, and underexpression of FHOD, SMAD4 and BCL2 was associated with losses. Pathway enrichment analysis showed that pathways of nitrogen metabolism, oxidative phosphorylation, cell cycle, maturity onset diabetes of young, cytokine-cytokine receptor interaction, MAPK signaling pathway and dentatorubropallidoluysian atrophy were influenced by copy number changes.

Genomic profiling of rectal adenoma and carcinoma by array-based comparative genomic hybridization

Background

Rectal cancer is one of the most common cancers in the world. Early detection and early therapy are important for the control of death caused by rectal cancer. The present study aims to investigate the genomic alterations in rectal adenoma and carcinoma.

Methods

We detected the genomic changes of 8 rectal adenomas and 8 carcinomas using array CGH. Then 14 genes were selected for analyzing the expression between rectal tumor and paracancerous normal tissues as well as from adenoma to carcinoma by real-time PCR. The expression of GPNMB and DIS3 were further investigated in rectal adenoma and carcinoma tissues by immunohistochemistry.

Results

We indentified ten gains and 22 losses in rectal adenoma, and found 25 gains and 14 losses in carcinoma. Gains of 7p21.3-p15.3, 7q22.3-q32.1, 13q13.1-q14.11, 13q21.1-q32.1, 13q32.2-q34, 20p11.21 and 20q11.23-q12 and losses of 17p13.1-p11.2, 18p11.32-p11.21 and 18q11.1-q11.2 were shared by both rectal adenoma and carcinoma. Gains of 1q, 6p21.33-p21.31 and losses of 10p14-p11.21, 14q12-q21.1, 14q22.1-q24.3, 14q31.3-q32.1, 14q32.2-q32.32, 15q15.1-q21.1, 15q22.31 and 15q25.1-q25.2 were only detected in carcinoma but not in adenoma. Copy number and mRNA expression of EFNA1 increased from rectal adenoma to carcinoma. C13orf27 and PMEPA1 with increased copy number in both adenoma and carcinoma were over expressed in rectal cancer tissues. Protein and mRNA expression of GPNMB was significantly higher in cancer tissues than rectal adenoma tissues.

Conclusion

Our data may help to identify the driving genes involved in the adenoma-carcinoma progression.

Reevaluation of serum p53 antibody as a tumor marker in colorectal cancer patients

PURPOSE

We reevaluated the serum p53 antibody (S-p53Ab) ELISA kit, which was approved as a tumor marker of colon cancer in the Japanese Health Insurance System in 2007.

METHODS

S-p53Ab was measured as a tumor marker in 154 colorectal cancer patients, and the results were categorized by clinical and pathological variables. We then compared the positive frequency of S-p53Ab, carcinoembryonic antigen (CEA), and carbohydrate 19-9 (CA19-9).

RESULTS

S-p53Ab was positive in 33.1% of the colorectal cancer patients. The positive rate was significantly higher in patients with lymph nodes metastasis (P = 0.025) and lymphatic invasion (P = 0.023). In patients with stage I colorectal cancer, the positive rate of S-p53Ab (23.7%) was significantly higher than that of CEA (5.3%) or CA19-9 (7.9%).

CONCLUSION

The approved kit for S-p53Ab testing was found to be an effective tumor marker of colorectal cancer. The positive rate of S-p53Ab was significantly higher in patients with cancer involvement of the lymphoid tissues. The positive rate of S-p53Ab was higher than that of CEA and CA19-9 in patients with stage I colorectal cancer, suggesting that the S-p53Ab is a useful tumor marker for patients with early-stage disease.

Advances in the surgical treatment of colorectal cancer liver metastases through ultrasound

Surgery remains the gold standard of treatment for colorectal cancer liver metastases (CLM). The only limitation of surgery for CLM is its technical feasibility, the key point being to leave enough remnant liver to ensure patient survival. This report describes a surgical procedure based extensively on ultrasound guidance, which allows for curative resection in one stage and also for multiple bilobar CLM. This strategy minimizes the need for two-stage hepatectomy and may thus overcome many of the limitations and consequences of a two-stage approach, such as the impossibility to complete the treatment approach in 20%-25% of patients and the amputation of major vascular structures, which can result in less technical solutions for CLM relapse.

Predictive markers of colorectal cancer liver metastases

Liver metastases are the most common site of distant failure after curative resection of colorectal cancer and a source of significant cancer-related morbidity and mortality. Currently, imaging and conventional histopathologic features, such as T-stage and N-stage, are used by clinicians to inform prognosis and guide adjuvant treatment to reduce the risk of developing distant metastases. However, these tools only have a moderate ability to predict the development of liver metastases. Novel methods, including the detection of circulating tumor cells and carcinoembryonic antigens in serum, have been developed, and their prognostic and predictive characteristics have been assessed. In addition, several molecular and genetic markers in the primary tumor have been studied. Unfortunately, these studies are often small and their results have been mixed, yielding no consistent sets of externally validated predictors of colorectal liver metastases. For widespread clinical relevance, future tests need to be independently carried out on large independent patient samples.