Risk of recurrent gastric cancer after endoscopic resection with a positive lateral margin

BACKGROUND AND STUDY AIMS

After noncurative endoscopic submucosal dissection (ESD) for differentiated-type early gastric cancer (EGC), close observation is often preferred when a cancer-positive lateral margin is the only noncurative factor. However, sometimes recurrence is found during the observation period. This study aimed to examine risk factors for recurrent cancer based on the long-term clinical outcomes after noncurative ESD in which the only noncurative factor was a cancer-positive lateral margin.

PATIENTS AND METHODS

Among 3784 EGCs (3316 patients) treated by ESD between 1997 and 2010, 77 noncurative differentiated-type EGCs (75 patients) were retrospectively analyzed after meeting the following inclusion criteria: 1) the only noncurative factor was a cancer-positive lateral margin; 2) close observation was selected after the ESD; and 3) > 1 year follow-up after ESD.

RESULTS

Locally recurrent cancer was found in 10 lesions within a median follow-up period of 59.8 months; no metastasis or gastric cancer-related death occurred. The cumulative incidence of local recurrence 5 years after ESD was 11.9 %. All locally recurrent cancers were mucosal differentiated-type adenocarcinomas. Multivariate analysis indicated that a cancer-positive lateral margin length of ≥ 6 mm was significantly associated with local recurrence (hazard ratio 20.8; 95 % confidence interval 5.2 % - 82.9 %; P < 0.001). The cut-off value of 6 mm was determined by the receiver operating characteristic curve; the sensitivity and specificity for 5-year risk of developing local recurrence were 66.7 % and 95.6 %, respectively.

CONCLUSIONS

A cancer-positive lateral margin length of ≥ 6 mm was an independent risk factor for local recurrence, and this may be a useful criterion for selecting high-risk cases for stricter management.

Primary lung adenocarcinoma with morule-like components: a unique histologic hallmark of aggressive behavior and EGFR mutation

BACKGROUND

Lung adenocarcinoma with morule-like components is an unusual variant of lung adenocarcinoma, comprising uniform, tightly packed spindle-shaped cells, which fill the lumen of the glandular structures of the carcinoma. The aim of the study was to outline the clinicopathologic features of this variant.

PATIENTS AND METHODS

We examined a series of 904 surgically resected adenocarcinomas. We defined morule-like components as small buds of spindle-cell proliferation in the tumor lumen of the glandular structures of the carcinoma and calculated their proportion of total tumor mass. Targeted genotyping was performed for KRAS, EGFR, HER2, and BRAF. ALK rearrangements were analyzed immunohistochemically. Immunopositive cases were confirmed using RT-PCR and/or FISH.

RESULTS

We detected 17 cases of adenocarcinoma with morule-like components. This variant, representing only 1.9% was associated with unfavorable outcomes and a mutation in the EGFR. Histologic examination revealed adenocarcinoma with morule-like components accounting for 5-50% of tumors. Among the morule-like components, 10 (58.8%) of the 17 samples showed intracytoplasmic lumina formation containing eosinophilic mucinous material. The presence of micropapillary components in adenocarcinoma with morule-like components suggests that morule-like components could be merely excessive growth of the micropapillary pattern. However, our results indicated no statistical differences in the MIB-1 indices of the morule-like components and the adjacent tumor components or the micropapillary components. The univariate and multivariate analyses revealed a correlation between the presence of a morule-like components and an unfavorable outcome.

CONCLUSIONS

Our study clearly indicated that adenocarcinoma with morule-like components is distinct unfavorable prognostic and predictor for EGFR mutation.

Frequent lack of GNAS mutations in colorectal adenocarcinoma associated with GNAS-mutated villous adenoma

Colorectal villous adenoma is thought to be associated with a high risk of progression to adenocarcinoma. To better characterize the genetic alterations involved in colorectal carcinogenesis related to villous adenoma, we analyzed mutations in APC, BRAF, KRAS, TP53, and GNAS in 12 colorectal adenocarcinomas associated with villous adenomas. APC, KRAS, and BRAF mutations were identified in five, 11, and one lesion, respectively, and most of these mutations were shared between the villous adenoma and the adenocarcinoma components in the respective lesions, except in one lesion with APC mutations and in two lesions with KRAS mutations. TP53 mutations were observed exclusively in four adenocarcinoma components, consistent with their role in the progression from adenoma to adenocarcinoma. Activating GNAS mutations were found in nine villous adenomas; however, unexpectedly, these mutations were shared only in three associated adenocarcinomas. Notably, all six adenocarcinomas with discordant GNAS mutation statuses were nonmucinous type, whereas all the other adenocarcinomas, including three adenocarcinomas associated with GNAS wild-type villous adenomas, were mucinous type. The current study suggests that GNAS-mutated villous adenomas may not necessarily be direct precursors of associated adenocarcinomas. At the same time, our observations support the role of activating GNAS mutations in increased mucin production in colorectal neoplasms.

Long-term outcome of endoscopic resection of superficial adenocarcinoma of the esophagogastric junction

BACKGROUND AND STUDY AIM

Endoscopic resection has been favored for the management of intramucosal adenocarcinoma of the esophagogastric junction (AEGJ) over standard treatment with surgical resection. Several previous studies have reported only short-term outcomes. The aim of the present study was to report the long-term follow-up and outcomes of endoscopic submucosal dissection (ESD), a representative endoscopic resection method, for the management of superficial AEGJ.

PATIENTS AND METHODS

A retrospective cohort study included 53 consecutive patients with superficial AEGJ who underwent ESD between 2001 and 2007 at the National Cancer Center Hospital, Tokyo, Japan. Rates of overall survival, recurrence-free survival, and cause-specific survival of patients with AEGJ after endoscopic resection were analyzed.

RESULTS

The 5-year overall, recurrence-free, and cause-specific survival rates in the 53 patients were 94.2%, 92.3% and 96.1%, respectively. The median follow-up was 6.1 years. En bloc, R0, and curative resection rates were 100 %, 79 %, 68 %, respectively. In 36 patients with curative resection, the cause-specific survival rate was 100 % and no recurrence or metastases were detected. In 17 patients with non-curative resection, recurrence was found in three patients (17 %); two of the three patients died of their disease whilst one patient received chemotherapy.

CONCLUSIONS

Superficial AEGJ can be well controlled by ESD when curative resection is achieved.

Bile acids increase levels of microRNAs 221 and 222, leading to degradation of CDX2 during esophageal carcinogenesis

BACKGROUND & AIMS

Bile reflux contributes to development of Barrett's esophagus (BE) and could be involved in its progression to esophageal adenocarcinoma (EAC). We investigated whether bile acids affect levels or functions of microRNAs (MIRs) 221 and 222, which bind to the 3'-UTR of p27Kip1 messenger RNA to inhibit its translation. Reduced p27Kip1 increases degradation of the transcription factor CDX2; levels of CDX2 have been reported to decrease during progression of BE to EAC.

METHODS

We used quantitative reverse transcriptase polymerase chain reaction to compare levels of MIRs 221 and 222 and immunohistochemistry to compare levels of p27Kip1 and CDX2 proteins in areas of BE and EAC from each of 11 patients. We examined the effects of bile acid exposure on levels of MIRs 221 and 222 and CDX2 in EAC cells. We investigated the effects of inhibitors of MIRs 221 and 222 on growth of human EAC xenograft tumors in NOD/SCID/IL-2Rγ(null) mice.

RESULTS

Levels of MIRs 221 and 222 increased and levels of p27Kip1 and CDX2 decreased in areas of EAC vs BE. Levels of MIRs 221 and 222 increased, along with activity of nuclear bile acid receptor/farnesoid X receptor (FXR), when cultured cells were exposed to bile acids. Incubation of cells with bile acids increased degradation of CDX2; this process was reduced when cells were also incubated with proteasome inhibitors. Overexpression of MIRs 221 and 222 reduced levels of p27Kip1 and CDX2, and knockdown of these MIRs increased levels of these proteins in cultured cells. Inhibitors of MIRs 221 and 222 increased levels of p27Kip1 and CDX2 in EAC cells and reduced growth of xenograft tumors in NOD/SCID/IL-2Rγ(null) mice.

CONCLUSIONS

We observed increased levels of MIRs 221 and 222 in human EAC tissues, compared with areas of BE from the same patient. We found that exposure of esophageal cells to bile acids activates FXR and increases levels of MIRs 221 and 222, reducing levels of p27Kip1 and promoting degradation of CDX2 by the proteasome. Our work opened the perspective of therapeutically targeting this pathway either via FXR antagonists or inhibitors of MIRs as a treatment option for BE and EAC.

Different histological status of gastritis in superficial adenocarcinoma of the esophagogastric junction

OBJECTIVE

Although many gastric cancers arise in chronic gastritis, the association between adenocarcinoma of the esophagogastric junction and the status of background gastritis remains unclear. We aim to investigate the histological status of gastritis in the background fundic gland mucosa of adenocarcinoma of the esophagogastric junction.

METHODS

The present study included 121 consecutive patients with superficial adenocarcinoma of the esophagogastric junction obtained by surgical and/or endoscopic resection. We re-evaluated the histogenesis of adenocarcinoma of the esophagogastric junction, including the background fundic gland mucosa using the Updated Sydney System. The prevalence of histologic atrophic gastric mucosa with gastritis (positive gastritis), non-atrophic gastric mucosa without gastritis (negative gastritis) and Barrett's adenocarcinoma was examined.

RESULTS

Histologic-positive gastritis was found in 67 (55%) of all patients, in 24 (38%) of 63 Barrett's adenocarcinoma patients and in 43 (74%) of 58 non-Barrett's adenocarcinoma patients (P < 0.01). A higher female ratio in non-Barrett's adenocarcinoma with gastritis patients `and younger age in non-Barrett's adenocarcinoma without gastritis patients were shown. There were no differences in clinicopathological features related to the gastritis status in Barrett's adenocarcinoma patients. Reflux esophagitis was observed in most (81%) of all patients, and 32 (74%) of the non-Barrett's adenocarcinoma with gastritis patients. In the 67 positive gastritis patients, the mean Updated Sydney System scores of glandular atrophy and intestinal metaplasia were 1.45 and 1.10, respectively, and these scores were higher in the non-Barrett's adenocarcinoma patients than in the Barrett's adenocarcinoma patients.

CONCLUSIONS

This study suggests that about half of the patients with adenocarcinoma of the esophagogastric junction harbor histological gastritis. Adenocarcinoma of the esophagogastric junction is considered to be a heterogeneous entity, including Barrett's esophagus-related, positive gastritis-related, and Barrett's esophagus and gastritis-unrelated adenocarcinoma of the esophagogastric junction.

Role of aquaporin-5 in gallbladder carcinoma

BACKGROUND/PURPOSE

Aquaporins (AQPs) are important in controlling bile formation. However, the exact role in human gallbladder carcinogenesis has not yet been defined.

METHODS

AQP-5-expressing gallbladder carcinoma (GBC) cell lines (NOZ) were transfected with anti-AQP-5 small interfering RNA (siRNA). Growth, migration, invasion assay, and drug susceptibility tests were performed. Next, microRNA (miRNA) expression was analyzed by miRNA oligo chip (3D-Gene®). AQP-5 and AQP-5-related miRNA target gene expressions were also analyzed using tissue microarray (TMA) in 44 GBC samples.

RESULTS

Treatment with AQP-5 siRNA decreased cell proliferation, migration, and invasion. On the other hand, those cells increased IC50 of gemcitabine. By performing miRNA assays, miR-29b, -200a, and -21 were shown to be highly overexpressed in cells treated with AQP-5 siRNA NOZ. When focusing on miR-21, phosphatase and tensin homolog (PTEN) was found to be a target of miR-21. In the TMA, AQP-5/PTEN coexpression was significantly associated with the depth of invasion and MIB-1 index (p = 0.003, 0.010). Survival of patients with a high AQP-5/PTEN coexpression was longer than that of patients with a low coexpression (p = 0.003).

CONCLUSIONS

Our result suggested that miR-21 and PTEN may contribute to the role of AQP-5 in GBC. AQP-5 and PTEN cascades are favorable biomarkers of GBC.

Soluble interleukin-6 receptor is a serum biomarker for the response of esophageal carcinoma to neoadjuvant chemoradiotherapy

Preoperative chemoradiotherapy has been shown to improve the outcome of patients with esophageal cancer, but because response to this therapy varies, it is desirable to identify in advance individuals who would be unlikely to benefit, in order to avoid unnecessary adverse drug effects. The serum profiles of 84 cytokines and related proteins were determined in 37 patients with esophageal squamous cell carcinoma who received identical neoadjuvant preoperative chemoradiotherapy regimens and underwent surgical resection. Histological response to this therapy was assessed in surgically resected specimens. The serum soluble interleukin-6 receptor (sIL6R) level was significantly higher in 30 patients who failed to achieve a histological complete response (P = 0.005). Multivariate analysis revealed that the increased level of sIL6R was one of several significant independent predictors of an unfavorable outcome (hazard ratio, 2.87; P = 0.017). The increased level of this cytokine in patients who did not obtain a complete response was reproducibly observed in an independent cohort of 34 patients. Esophageal squamous cell carcinoma patients with an increased serum level of sIL6R are predicted to respond poorly to preoperative chemoradiotherapy, therefore, their exclusion from this treatment may be considered. Persistent systemic inflammation is implicated as a possible mechanism of resistance to this therapy.

Frequent GNAS mutations in low-grade appendiceal mucinous neoplasms

Background:

The molecular basis for the development of appendiceal mucinous tumours, which can be a cause of pseudomyxoma peritonei, remains largely unknown.

Methods:

Thirty-five appendiceal mucinous neoplasms were analysed for GNAS and KRAS mutations. A functional analysis of mutant GNAS was performed using a colorectal cancer cell line.

Results:

A mutational analysis identified activating GNAS mutations in 16 of 32 low-grade appendiceal mucinous neoplasms (LAMNs) but in none of three mucinous adenocarcinomas (MACs). KRAS mutations were found in 30 LAMNs and in all MACs. We additionally analysed a total of 186 extra-appendiceal mucinous tumours and found that GNAS mutations were highly prevalent in intraductal papillary mucinous tumours of the pancreas (88%) but were rare or absent in mucinous tumours of the colorectum, ovary, lung and breast (0–9%). The prevalence of KRAS mutations was quite variable among the tumours. The introduction of the mutant GNAS into a colorectal cancer cell line markedly induced MUC2 and MUC5AC expression, but did not promote cell growth either in vitro or in vivo.

Conclusion:

Activating GNAS mutations are a frequent and characteristic genetic abnormality of LAMN. Mutant GNAS might play a direct role in the prominent mucin production that is a hallmark of LAMN.

Frequent GNAS and KRAS mutations in pyloric gland adenoma of the stomach and duodenum

Gastric and duodenal adenomas exhibit a significant morphological and phenotypical diversity and are classified into intestinal-type, foveolar-type and pyloric gland adenomas. We analysed the mutations in GNAS, KRAS, BRAF and CTNNB1 and the expressions of mismatch repair (MMR) proteins in 80 gastric and 32 duodenal adenomas with histologically distinct subtypes, as well as in 71 gastric adenocarcinomas. Activating GNAS mutations were found in 22 of the 35 pyloric gland adenomas (PGAs; 63%) but in none of the foveolar-type or intestinal-type adenomas or the adenocarcinomas. Fourteen PGAs (41%), two foveolar-type adenomas (9%), five intestinal-type adenomas (9%) and one adenocarcinoma (1%) had KRAS mutations. BRAF mutations were absent in all the adenomas and adenocarcinomas that were examined. CTNNB1 mutations were only found in two intestinal-type adenomas (4%). Notably, 13 of the 14 KRAS-mutated gastric and duodenal PGAs had concurrent GNAS mutations. The loss of the MMR proteins, which is indicative of microsatellite instability, was observed in one PGA (3%), 12 foveolar-type adenomas (52%), one intestinal-type adenoma (2%) and five adenocarcinomas (7%). These observations indicate that each histological subtype of gastric and duodenal adenomas has a distinct genetic background. In particular, the present study identified the frequent presence of activating GNAS mutations, which are often associated with KRAS mutations, as a characteristic genetic feature of PGAs of the stomach and duodenum.

Prevalence of MED12 mutations in uterine and extrauterine smooth muscle tumours

AIMS

To determine the prevalence of MED12 mutations in smooth muscle tumours of different organs.

METHODS AND RESULTS

A total of 142 smooth muscle tumours of the uterus, gastrointestinal tract, retroperitoneum and soft tissue were analysed for MED12 mutations using Sanger sequencing. Among the uterine tumours that were examined, MED12 mutations were identified in 36 of 45 conventional leiomyomas (80%), two of six cellular leiomyomas (33%), one of four bizarre leiomyomas (25%), none of four lipoleiomyomas (0%), and two of 12 leiomyosarcomas (17%). The two MED12-mutated leiomyosarcomas were associated with benign leiomyomatous components that also harboured MED12 mutations identical to those in the respective leiomyosarcomatous components. None of the extrauterine smooth muscle tumours, including the leiomyomas, leiomyosarcomas, and angioleiomyomas, had MED12 mutations.

CONCLUSIONS

Among uterine smooth muscle tumours, MED12 mutations are frequently present in conventional leiomyomas, but are significantly less common in histological variants of leiomyoma and leiomyosarcoma. In contrast to uterine lesions, none of the extrauterine smooth muscle tumours had MED12 mutations.

Urinary podocalyxin is an early marker for podocyte injury in patients with diabetes: establishment of a highly sensitive ELISA to detect urinary podocalyxin

AIMS/OBJECTIVE

Nephropathy, a major complication of diabetes, is the leading cause of end-stage renal disease. Recent studies have demonstrated that podocyte injury is involved in the onset of and progression to renal insufficiency. Here, we describe a novel, highly sensitive ELISA for detecting urinary podocalyxin, a glycoconjugate on the podocyte apical surface that indicates podocyte injury, particularly in the early phase of diabetic nephropathy.

METHODS

Urine samples from patients with glomerular diseases (n = 142) and type 2 diabetes (n = 71) were used to quantify urinary podocalyxin by ELISA. Urine samples were obtained from 69 healthy controls for whom laboratory data were within normal values. Podocalyxin was detected in urine by immunofluorescence, immunoelectron microscopy and western blotting.

RESULTS

Morphologically, urinary podocalyxin was present as a vesicular structure; western blotting showed it as a positive band at 165-170 kDa. Levels of urinary podocalyxin were elevated in patients with various glomerular diseases and patients with diabetes. In patients with diabetes, urinary podocalyxin was higher than the cut-off value in 53.8% patients at the normoalbuminuric stage, 64.7% at the microalbuminuric stage and 66.7% at the macroalbuminuric stage. Positive correlations were observed between urinary podocalyxin levels and HbA(1c), urinary β(2) microglobulin, α(1) microglobulin and urinary N-acetyl-β-D-glucosaminidase, although urinary podocalyxin levels were not correlated with other laboratory markers such as blood pressure, lipid level, serum creatinine, estimated GFR or proteinuria.

CONCLUSIONS/INTERPRETATION

Urinary podocalyxin may be a useful biomarker for detecting early podocyte injury in patients with diabetes.

Frequent activating GNAS mutations in villous adenoma of the colorectum

To elucidate the role of GNAS mutations in colorectal tumourigenesis, we performed a mutation analysis in a total of 234 colorectal tumours, including adenomas, serrated lesions and adenocarcinomas. Activating GNAS mutations were found in 20 of the 24 villous adenomas (83%) but were absent in all the other tumours, except for one tubulovillous adenoma (3%) and two adenocarcinomas (3%). KRAS and BRAF mutations were always mutually exclusive. KRAS mutations were frequent in villous (67%) and tubulovillous (60%) adenomas but were rare or absent in tubular adenomas (6%) and serrated lesions, including hyperplastic polyps, sessile serrated polyps/sessile serrated lesions and traditional serrated adenomas (0-9%). BRAF mutations were found in four villous adenomas (17%) and in the large majority of serrated lesions (81-92%), but were absent in tubular and tubulovillous adenomas. Seventeen villous adenomas (71%) harboured GNAS mutations concomitantly with KRAS or BRAF mutations. Immunohistochemically, all the villous adenomas retained mismatch repair protein expression, suggesting that they are microsatellite-stable. The current study showed that the presence of activating GNAS mutations, in association with KRAS or BRAF mutations, is a characteristic genetic feature of colorectal villous adenoma.

Clinicopathological characteristics and prognostic factors of advanced colorectal mucinous adenocarcinoma

AIMS

Mucinous adenocarcinoma (MUC) is a histological variant of colorectal adenocarcinoma. The aim of the present study was to characterize clinicopathological features and identify prognostic factors of MUCs.

METHODS AND RESULTS

A total of 181 patients with MUC who underwent surgery between 1975 and 2003 were reviewed. The clinicopathological features of these patients were compared with those of 4125 non-MUC patients. Univariate and multivariate analyses were conducted to identify significant prognostic factors in 102 patients with pT3 or pT4 tumour who underwent curative surgery. Patients with MUCs tended to present with more advanced clinical stages. The overall 5-year survival rate of MUC patients was lower than that of non-MUC patients; however, no prognostic difference was found when patients with the same clinical stages were compared. Multivariate analysis revealed male sex, bowel obstruction and infiltrating growth type as independent prognostic factors. Five-year cancer-specific survival rates for MUC patients with ≤1, 2 and 3 risk factors identified by multivariate analysis were 95.5%, 52.1% and 0.0%, respectively (P < 0.001).

CONCLUSIONS

Mucinous adenocarcinoma represents a distinct clinicopathological entity. Sex, bowel obstruction and growth patterns might be useful prognostic factors to identify patients with a high risk of recurrence after curative resection of advanced MUCs.

Hepatocyte nuclear factor 4A expression discriminates gastric involvement by metastatic breast carcinomas from primary gastric adenocarcinomas

Breast carcinomas sometimes metastasize to the stomach, and the histopathologic distinction of such metastases from primary gastric adenocarcinomas is often difficult. We characterized the clinicopathologic features of 21 breast carcinomas that had metastasized to the stomach and examined the use of a panel of antibodies, including hepatocyte nuclear factor 4A, for distinguishing the metastases from primary gastric diffuse-type adenocarcinomas. Histologically, all the metastatic breast carcinomas showed a poorly differentiated and/or signet ring cell morphology. Although most metastatic breast and primary gastric carcinomas contained signet ring cell components, the cases that were predominantly or exclusively composed of univacuolated-type signet ring cells were limited to metastatic breast carcinomas. Immunohistochemically, hepatocyte nuclear factor 4A was expressed in all 33 primary gastric carcinomas that were examined but was never expressed in metastatic breast carcinomas. Previously reported markers for breast and gastric carcinomas also showed a high specificity, but their sensitivities were quite variable. Estrogen receptor α, progesterone receptor, mammaglobin, and gross cystic disease fluid protein 15 were expressed in 76%, 33%, 52%, and 62%, respectively, of the metastatic breast carcinomas, whereas none of the primary gastric carcinomas expressed these antigens. CDX2, MUC5AC, MUC6, and CK20 were expressed in 36%, 85%, 27%, and 55%, respectively, of the primary gastric carcinomas. All the metastatic breast carcinomas were negative for these antibodies except for 1 case that expressed MUC5AC. Overall, the use of immunohistochemistry efficiently discriminated metastatic breast carcinomas from primary gastric carcinomas. In particular, the present study identified hepatocyte nuclear factor 4A as an excellent marker for differentiating the 2 lesions.

Ring-like enhancement of focal nodular hyperplasia with hepatobiliary-phase Gd-EOB-DTPA-enhanced magnetic resonance imaging: radiological-pathological correlation

We report a case of focal nodular hyperplasia in a patient for whom gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) and histological analysis results were available. Dynamic contrast-enhanced computed tomography showed a well-defined hypervascular lesion 14 mm in diameter with no visible central scars. Gd-EOB-DTPA-enhanced MRI demonstrated strong peripheral enhancement of the lesion during the hepatobiliary phase, resulting in ring-like enhancement. The pathology examination revealed that the lesion was focal nodular hyperplasia (FNH). Immunohistochemistry showed positive expression of OATP8 in the hepatocytes in the peripheral areas of the lesion, whereas expression of OATP8 was lacking in hepatocytes surrounding the central radiating scar. Ring-like enhancement during the hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI may be an important clue for the diagnosis of small FNH.

Identification of adipophilin as a potential plasma biomarker for colorectal cancer using label-free quantitative mass spectrometry and protein microarray

BACKGROUND

The aim of this study was to identify a new plasma biomarker for use in early detection of colorectal cancer.

METHODS

Using the combination of hollow fiber membrane (HFM)-based low-molecular weight protein enrichment and two-dimensional image converted analysis of liquid chromatography and mass spectrometry (2DICAL), we compared the plasma proteome of 22 colorectal cancer patients with those of 21 healthy controls. An identified biomarker candidate was then validated in two larger cohorts [validation-1 (n = 210) and validation-2 (n = 113)] using a high-density reverse-phase protein microarray.

RESULTS

From a total of 53,009 mass peaks, we identified 103 with an area under curve (AUC) value of 0.80 or higher that could distinguish cancer patients from healthy controls. A peak that increased in colorectal cancer patients, with an AUC of 0.81 and P value of 0.0004 (Mann-Whitney U test), was identified as a product of the PLIN2 gene [also known as perilipin-2, adipose differentiation-related protein (ADRP), or adipophilin]. An increase in plasma adipophilin was consistently observed in colorectal cancer patients, including those with stage I or stage II disease (P < 0.0001, Welch's t test). Immunohistochemical analysis revealed that adipophilin is expressed primarily in the basal sides of colorectal cancer cells forming polarized tubular structures, and that it is absent from adjacent normal intestinal mucosae.

CONCLUSIONS

Adipophilin is a plasma biomarker potentially useful for the detection of early-stage colorectal cancer.

IMPACT

The combination of HFM and 2DICAL enables the comprehensive analysis of plasma proteins and is ideal for use in all biomarker discovery studies.

Expression of SLCO1B3 is associated with intratumoral cholestasis and CTNNB1 mutations in hepatocellular carcinoma

Recent studies have shown that intratumoral cholestasis is a hallmark of CTNNB1 mutations in hepatocellular carcinomas (HCC). Here, we analyzed the expressions of genes involved in bile acid and bilirubin metabolism and their correlation with the mutational status of CTNNB1 in a series of HCC. The expressions of CYP7A1 and CYP27A1, which encode rate-limiting enzymes in bile acid synthesis, were unaltered or only marginally increased in CTNNB1-mutated HCC compared with those in HCC with wild-type CTNNB1. Among the genes involved in bile acid and bilirubin transport, the expression of SLCO1B3 was significantly elevated in HCC with CTNNB1 mutations, whereas the expression of ABCC4 was elevated in HCC with wild-type CTNNB1. Immunohistochemistry confirmed the frequent expression of SLCO1B3 in CTNNB1-mutated HCC at the protein level, but not in most HCC with wild-type CTNNB1. Immunohistochemistry for MRP4 (encoded by ABCC4) partly agreed with ABCC4 expression, but most cases did not express detectable levels of MRP4. Notably, all HCC with bile accumulation, including those without CTNNB1 mutations, expressed SLCO1B3, suggesting that SLCO1B3 expression, rather than CTNNB1 mutation, is the critical determinant of intratumoral cholestasis. As SLCO1B3 is involved in the uptake of a number of chemotherapeutic and diagnostic agents, SLCO1B3 expression and the status of CTNNB1 mutation might need to be considered in the drug delivery to HCC.