PURPOSE: The serum carcinoembryonic antigen (CEA) level has been recognized as a prognostic factor in colorectal cancer, and associated with response of rectal cancer to radiotherapy. This study aimed to identify CEA-interacting proteins in colon cancer cells and observe post-irradiation changes in their expression. MATERIALS AND METHODS: CEA expression in colon cancer cells was examined by Western blot analysis. Using an anti-CEA antibody or IgG as a negative control, immunoprecipitation was performed in colon cancer cell lysates. CEA and IgG immunoprecipitates were used for liquid chromatography–tandem mass spectrometry (LC-MS/MS) analysis. Proteins identified in the CEA immunoprecipitates but not in the IgG immunoprecipitates were selected as CEA-interacting proteins. After radiation treatment, changes in expression of CEA-interacting proteins were monitored by Western blot analysis. RESULTS: CEA expression was higher in SNU-81 cells compared with LoVo cells. The membrane localization of CEA limited the immunoprecipitation results and thus the number of CEA-interacting proteins identified. Only the Ras-related protein Rab-6B and lysozyme C were identified as CEA-interacting proteins in LoVo and SNU-81 cells, respectively. Lysozyme C was detected only in SNU-81, and CEA expression was differently regulated in two cell lines; it was down-regulated in LoVo but up-regulated in SNU-81 in radiation dosage-dependent manner. CONCLUSION: CEA-mediated radiation response appears to vary, depending on the characteristics of individual cancer cells. The lysozyme C and Rab subfamily proteins may play a role in the link between CEA and tumor response to radiation, although further studies are needed to clarify functional roles of the identified proteins.
Blotting, Western ; Carcinoembryonic Antigen ; Cell Line ; Colon* ; Colonic Neoplasms* ; Colorectal Neoplasms ; Immunoglobulin G ; Immunoprecipitation ; Mass Spectrometry ; Membranes ; Muramidase ; Radiotherapy ; Rectal Neoplasms

PURPOSE: The serum carcinoembryonic antigen (CEA) level has been recognized as a prognostic factor in colorectal cancer, and associated with response of rectal cancer to radiotherapy. This study aimed to identify CEA-interacting proteins in colon cancer cells and observe post-irradiation changes in their expression. MATERIALS AND METHODS: CEA expression in colon cancer cells was examined by Western blot analysis. Using an anti-CEA antibody or IgG as a negative control, immunoprecipitation was performed in colon cancer cell lysates. CEA and IgG immunoprecipitates were used for liquid chromatography–tandem mass spectrometry (LC-MS/MS) analysis. Proteins identified in the CEA immunoprecipitates but not in the IgG immunoprecipitates were selected as CEA-interacting proteins. After radiation treatment, changes in expression of CEA-interacting proteins were monitored by Western blot analysis. RESULTS: CEA expression was higher in SNU-81 cells compared with LoVo cells. The membrane localization of CEA limited the immunoprecipitation results and thus the number of CEA-interacting proteins identified. Only the Ras-related protein Rab-6B and lysozyme C were identified as CEA-interacting proteins in LoVo and SNU-81 cells, respectively. Lysozyme C was detected only in SNU-81, and CEA expression was differently regulated in two cell lines; it was down-regulated in LoVo but up-regulated in SNU-81 in radiation dosage-dependent manner. CONCLUSION: CEA-mediated radiation response appears to vary, depending on the characteristics of individual cancer cells. The lysozyme C and Rab subfamily proteins may play a role in the link between CEA and tumor response to radiation, although further studies are needed to clarify functional roles of the identified proteins.
Blotting, Western ; Carcinoembryonic Antigen ; Cell Line ; Colon* ; Colonic Neoplasms* ; Colorectal Neoplasms ; Immunoglobulin G ; Immunoprecipitation ; Mass Spectrometry ; Membranes ; Muramidase ; Radiotherapy ; Rectal Neoplasms

PURPOSE: This study was designed to evaluate the effectiveness of the transrectal ultrasound (TRUS) guided prostatic peripheral 10-sites biopsy method for the diagnosis of prostatic cancer. MATERIALS AND METHODS: TRUS guided biopsy of peripheral 10-sites, including routine sextant and 4 far lateral regions (lateral mid-lobes and bases), was performed in 78 patients with suspicious prostatic cancer. The patients were categorized into 2 groups; the benign disease group and the prostatic cancer group, according to the pathologic results. Various parameters were compared between the 2 groups. RESULTS: Prostatic cancer was detected in 32 patients (41%). The median age and PSA of the prostatic cancer group, 70.5 years and 25ng/ml, respectively, were significantly higher than those of the benign disease group, 63.5 years and 9.7ng/ml, respectively (p<0.05). The average Gleason scores and number of cancer positive biopsies of the prostatic cancer group were 7.3 (4-10) and 4.5 (1-10), respectively. A far lateral region only tumor was discovered in 1 (3.1%) of the 32 patients. The cancer detection rate increased with increasing PSA level (p<0.05). Patients with a prostate volume of less than 50cc showed significantly higher cancer detection rates than those with a prostate volume of more than 50cc (p<0.05). Fifty-four patients (69%) experienced complications and 4, with symptomatic urinary tract infection, recovered uneventfully with the application of parenteral antibiotics on admission. CONCLUSIONS: There was a 3.1% increase in the cancer detection rate with the use of a peripheral 10-sites biopsy compared to the sextant method. The use of additional biopsies, including those of the far lateral apex region, with the 10-sites biopsy method is suggested would increase detection rates.
Anti-Bacterial Agents ; Biopsy* ; Diagnosis ; Humans ; Prostate* ; Prostatic Neoplasms ; Ultrasonography ; Urinary Tract Infections

PURPOSE: Patients show variable responses to chemoradiotherapy (CRT), which is generally administered before surgery for locally advanced rectal cancer (LARC). The aim of this study was to identify molecular markers predictive of CRT responses by analysis of low-mass ions (LMIs) in serum of LARC patients. MATERIALS AND METHODS: LMIs (< 1,000 m/z) in serum obtained before CRT from 73 LARC (cT3-4) patients were profiled using matrix-assisted laser desorption/ionization mass spectrometry. LMIs with higher weighting factors in discriminating CRT responses were selected using principal components analysis and discriminant analysis. Selected LMIs were identified using the Human Metabolome Database. The concentrations of identified LMIs were determined by colorimetric enzyme assay, and compared according to post-CRT pathological stage (ypStage) or Dworak's tumor regression grade (TRG). RESULTS: The nine highest-ranking LMIs were selected. Among them, two LMIs with 137.08 and 169.04 m/z were identified as hypoxanthine (HX) and phosphoenolpyruvic acid (PEP), respectively. Higher HX concentration was observed in patients with ypStage 0-1 compared to ypStage 2-4 (p=0.034) or ypStage 3-4 (p=0.030); a similar difference was observed between TRG 4-3 and TRG 1 (p=0.035). HX > 16.0 muM showed significant association with ypStage 0-1 or TRG 4-3 than ypStage 3-4 (p=0.009) or TRG 1 (p=0.024), respectively. In contrast, a significantly lower concentration of PEP was observed in TRG 4-3 compared with TRG 2-1 (p=0.012). CONCLUSION: Findings of this study demonstrated that serum concentrations of HX and PEP, identified using LMI profiling, may be useful for predicting the CRT response of LARC patients before treatment.
Biological Markers* ; Chemoradiotherapy* ; Enzyme Assays ; Humans ; Hypoxanthine* ; Ions ; Mass Spectrometry ; Metabolome ; Phosphoenolpyruvate ; Rectal Neoplasms*

Cancer is a complex, heterogeneic, and dynamic disease involving multiple gene-environment interactions, and affecting numerous biological pathways. As such, the development of reliable and robust non-invasive platforms constitutes a vital step toward realizing the potential of precision medicine. Distant metastases harbor unique genomic characteristics that are not detectable in the corresponding primary tumor of the same patient, and metastases located at different sites show considerable intra-patient heterogeneity. Thus, the analysis of the resected primary tumor alone or, if possible, re-evaluation of tumor characteristics based on the biopsy of the most accessible metastasis, may not reveal sufficient information for treatment decisions. Here, we propose that this dilemma can be solved by a new diagnostic concept: liquid biopsy, that is, the analysis of therapeutic targets and drug resistance-conferring gene mutations in or on circulating tumor cells (CTCs). Finally, the analysis of the resected primary tumor alone may provide misleading information with regard to the characteristics of metastases, the key target for systemic anticancer therapy. Liquid biopsies are noninvasive tests using blood or fluids that detect CTCs or the products of tumors, such as fragments of nucleotides or proteins that are shed into biological fluids from the primary or metastatic tumors. Such biopsies are expected to be informative or easily accessible tools to provide comprehensive information regarding cancers beyond conventional biopsies. Thus, this review addresses the use of CTCs in cancer detection, diagnosis and monitoring and discusses the direction of its clinical application in cancer patient care.
Biopsy ; Diagnosis ; Early Detection of Cancer ; Gene-Environment Interaction ; Humans ; Neoplasm Metastasis ; Neoplastic Cells, Circulating ; Nucleotides ; Patient Care ; Population Characteristics ; Precision Medicine