Retrograde vs Conventional Dissection Technique in Pancreaticoduodenectomy: A Pilot Study

IMPORTANCE

A retrograde dissection technique of pancreaticoduodenectomy in a caudocranial direction has been described recently.

OBSERVATIONS

Fifteen consecutive patients who underwent retrograde pancreaticoduodenectomy were compared with 15 consecutive patients operated on through a conventional approach. The mean (SD) intraoperative blood loss was 407 (202) mL in the retrograde group compared with 423 (253) mL in the conventional group (P = .84). The mean (SD) operative duration was 255 (57) minutes in the retrograde group compared with 264 (54) minutes in the conventional group (P = .66). The overall morbidity was 7 of 15 patients (47%) in the retrograde group and 6 of 15 (40%) in the conventional group (P > .99). Neither group had a positive resection margin or a perioperative death.

CONCLUSIONS AND RELEVANCE

The retrograde dissection technique had no significant difference in perioperative outcomes compared with the conventional dissection technique and could serve as an alternative dissection approach in pancreaticoduodenectomy.

Identification and assessment of new biomarkers for colorectal cancer with serum N-glycan profiling

BACKGROUND

The objectives of this study were to identify and validate the diagnostic value of N-glycan markers in colorectal cancer (CRC) and to uncover their underlying molecular mechanism.

METHODS

In total, 347 individuals, including patients with CRC, patients with colorectal adenoma, and healthy controls, were divided randomly into a training group (n = 287) and retrospective validation groups (n = 60). Serum N-glycan profiling was analyzed by DNA sequencer-assisted/flurophore-assisted carbohydrate electrophoresis (DSA-FACE). Two diagnostic models were constructed based on N-glycan profiling with logistic stepwise regression. The diagnostic performance of each model was assessed further in retrospective, prospective (n = 43), and follow-up (n = 46) cohorts. Lectin blot and reverse transcriptase-polymerase chain reaction were used to analyze the total core-fucosylated residues and molecular expression involved in core-fucosylation modifications in CRC.

RESULTS

Two diagnostic models designated CRCglycoA and CRCglycoB were constructed to differentiate CRC from normal and adenoma, respectively. The areas under the receiver operating characteristic curves (AUC) of both CRCglycoA and CRCglycoB were higher than the AUC of carcinoembryonic antigen (CEA) (CRCglycoA, 0.92 vs 0.81; CRCglycoB, 0.81 vs 0.73). The sensitivity and accuracy of CRCglycoA improved from 21.7% to 25% and from 11.63% to 18% in the training cohort, the retrospective cohort, and the prospective cohorts compared with the sensitivity and accuracy of CEA. The sensitivity of CRCglycoB improved from 20% to 28.23%. Both altered N-glycans, and results from the diagnostic models were reversed after curative surgery. The level of total core fucose residues and fucosyltransferase were decreased significantly in CRC.

CONCLUSIONS

The current results indicated that the N-glycan markers based diagnostic models are new, valuable, noninvasive alternatives for identifying CRC. The authors concluded that decreased fucosyltransferase may be responsible for decreased levels of total core-fucosylated modification in both tissues and serum from patients with CRC.

Increased expression of annexin A1 is correlated with K-ras mutation in colorectal cancer

The activation of K-ras gene and expression of annexin A1 play an important role in colorectal tumorigenesis. We initiated this study to analyze the possible relationship between the annexin A1 expression and the K-ras mutation status in colorectal cancer. K-ras mutations are present in one fourth to one half of colorectal cancers. Annexin A1, a 37-kDa calcium- and phospholipid-binding protein, is over-expressed in colorectal cancers and may be involved in invasive tumor growth and metastasis. Here, we examined twenty paired specimens of colorectal cancer and adjacent normal tissues for K-ras mutations and annexin A1 expression. Sequencing analysis of codons 12 and 13 of K-ras revealed the presence of K-ras mutations in six colorectal cancer tissue specimens (30%). RT-PCR and immunoblotting studies further found that the expression levels of annexin A1 mRNA and protein were increased (2.9-fold and 1.7-fold, respectively) in colorectal cancers harboring K-ras codon 12 or codon 13 mutation compared with adjacent normal tissues (P < 0.05). In colorectal cancer tissues with wild-type K-ras, 12 (85.7%) specimens showed reduced expression of annexin A1 (0.48-fold and 0.81-fold, respectively). No significant association was found between K-ras mutations or annexin A1 over-expression and demographic or other clinicopathological parameters such as gender, differentiation or metastasis. However, a significant and positive correlation was identified between K-ras mutations and annexin A1 over-expression. Our findings indicate that annexin A1 could be implicated in colorectal cancer development and progression and could be of potential use as a predictive marker for guiding targeted therapy for colorectal cancer.

Cellular prion protein promotes glucose uptake through the Fyn-HIF-2α-Glut1 pathway to support colorectal cancer cell survival

Cellular prion protein (PrPc) is a glycosylphosphatidylinositol-anchored membrane protein that has various physical functions, including protection against apoptotic and oxidative stress, cellular uptake of copper ions, transmembrane signaling, and adhesion to the extracellular matrix. In this study, we show that PrPc is highly expressed in colorectal adenocarcinomas. Transcriptome profiling of PrPc-depleted DLD-1 cells revealed downregulation of glucose transporter 1 (Glut1). PrPc is shown to be involved in regulating Glut1 expression through the Fyn-HIF-2α pathway. As Glut1 is the natural transporter of glucose and is required for the high glycolytic rate seen in colorectal tumors, silencing of PrPc reduced the proliferation and survival rate of colorectal cancer cells in vitro. In vivo, knockdown of PrPc by hydrodynamic injection with a cocktail of PrPc-shRNA-encoding plasmids also inhibited tumorigenicity in a xenograft model in nude mice. In summary, our data characterize a novel molecular mechanism that links PrPc expression to the regulation of glycolysis. Targeting PrPc will therefore be a promising strategy to overcome the growth and survival advantage in colorectal tumors.