Portal vein wedge resection and patch venoplasty with autologous vein grafts for hepatobiliary-pancreatic cancer

BACKGROUND

Advanced hepatobiliary-pancreatic cancer often invades critical blood vessels, including the portal vein (PV) and hepatic artery. Resection with tumor-free resection margins is crucial to achieving a favorable prognosis in these patients. Herein, we present our cases and surgical techniques for PV wedge resection with patch venoplasty using autologous vein grafts during surgery for pancreatic ductal adenocarcinoma (PDAC) and perihilar cholangiocarcinoma (PhCC).

CASE PRESENTATION

Case 1: 73-year-old female patient with PDAC; underwent subtotal stomach-preserving pancreatoduodenectomy, with superior mesenteric vein wedge resection and venoplasty with the right gonadal vein. Case 2: 67-year-old male patient with PDAC; underwent distal pancreatectomy and celiac axis resection, with PV wedge resection and venoplasty with the middle colic vein. Case 3: 51-year-old female patient with type IV PhCC; underwent left hepatectomy with caudate lobectomy and bile duct resection, with hilar PV wedge resection and venoplasty with the inferior mesenteric vein (IMV). Case 4: 69-year-old male patient with type IIIA PhCC; underwent right hepatopancreatoduodenectomy, with hilar PV resection and patch venoplasty with the IMV. All patients survived for over 12 months after the surgery, without local recurrence.

CONCLUSIONS

PV wedge resection and patch venoplasty is a useful technique for obtaining tumor-free margins in surgeries for hepatobiliary-pancreatic cancer.

[A Case Report-A Successful Case of Distal Pancreatectomy with En Bloc Celiac Axis Resection for Locally Advanced Pancreatic Cancer with an Aberrant Right Hepatic Artery]

In cases of pancreatic cancer with anatomical variations of the hepatic artery, it is important to evaluate the hemodynamics of each case for surgical indication. We report the case of a 68-year-old man with locally advanced pancreatic cancer and an aberrant right hepatic artery who underwent distal pancreatectomy with celiac axis resection(DP-CAR). He was admitted to our institute due to abdominal discomfort. A CT scan showed pancreatic cancer invading the common hepatic artery. He underwent chemoradiotherapy with a diagnosis of locally advanced pancreatic cancer. After the tumor downstaging, we performed DP-CAR, which included a gastroduodenal artery and a proper hepatic artery resection. Even though delayed gastric emptying was observed after the operation, he was discharged on postoperative day 36.

Maternal heart rate variability patterns associated with maternal hypotension and non-reassuring fetal heart rate patterns following initiation of combined spinal-epidural labor analgesia: a prospective observational trial

BACKGROUND

We evaluated whether baseline maternal heart rate variability (HRV), including the Analgesia Nociception Index (ANI), is associated with maternal hypotension and fetal heart rate (FHR) abnormalities following combined spinal-epidural (CSE) labor analgesia.

METHODS

Laboring women were enrolled in this prospective observational study. The primary endpoint was maternal hypotension. The secondary endpoint was FHR abnormalities within 30 min following CSE analgesia initiated with intrathecal plain bupivacaine 1.0 mg and fentanyl 20 µg. The maternal ANI, electrocardiogram, blood pressure, heart rate, oxygen saturation, and FHR tracings were recorded 15 min before and 30 min after CSE. Parturients were grouped based on presence of hypotension and FHR abnormalities. Patient demographics and HRV metrics were compared. Receiver operating characteristics (ROC) curves were constructed for the prediction of hypotension and FHR abnormalities.

RESULTS

No significant intergroup differences were detected in patient characteristics. Several baseline HRV metrics and ANI differed significantly between the normotensive (n = 50) and hypotensive (n = 31) groups and between parturients showing FHR abnormalities (n = 19) and those showing reassuring FHR traces (n = 62). The area under the ROC curve (AUC) for predicting hypotension of the baseline low-frequency (LF)/high-frequency (HF) ratio was 0.677 (95% CI 0.55 to 0.80), and that of the ANI was 0.858 (95% CI 0.78 to 0.94). For predicting non-reassuring FHR patterns, the AUC of the LF/HF ratio was 0.77 (95% CI 0.65 to 0.89), and that of the ANI was 0.833 (95% CI 0.72 to 0.94).

CONCLUSIONS

The ANI can predict the propensity for maternal hypotension and non-reassuring FHR patterns following CSE.

[FOLFIRI plus RAM Therapy in Later Line of Unresectable Colorectal Cancer]

FOLFIRI plus ramucirumab(RAM)therapy has been reported to be effective and safe in the RAISE trial as second-line treatment for unresectable colorectal cancer. It is hypothesized that RAM may be effective in patients with PD treated with FOLFIRI plus bevacizumab(Bev)due to different mechanism of action from that of Bev, which is also an angiogenesis inhibitor. From January 2017 to December 2021, we conducted a retrospective study of 6 patients who had PD with 5-FU, oxaliplatin, irinotecan, or Bev as first or second-line treatment at our institution and who received FOLFIRI plus RAM in later line treatment. The 6 cases consisted of 3 patients in the third-line treatment, 1 patient in the fourth-line treatment, and 2 patients in the sixth-line treatment. The anti-tumor effect was PD in all cases in the third-line and fourth-line treatment, but the 2 patients of sixth-line treatment were controlled diseases.

Single-Incision Laparoscopic Cholecystectomy: a Single-Centre Experience of 1469 Cases

BACKGROUND

Despite having once been extensively used for cosmetics or pain reduction, the use of single-incision laparoscopic cholecystectomy (SILC) has declined in recent years due to technical difficulties and a reported increase in complications. Since the introduction of SILC in 2009, our hospital has been actively involved with this technique. Our experience suggests that SILC is not a difficult procedure and can be safe and useful, with particularly excellent cosmetic outcomes. This study retrospectively details the outcomes of SILC at our hospital.

METHOD

Data on 1469 cases of SILC performed on a waitlist basis at Osaka Police Hospital from May 2009 to December 2020 were collected and retrospectively analysed.

RESULTS

The median operative time and blood loss were 96 min and 0 mL, respectively. A total of 46 patients (3.1%) required conversion surgery, including 36 needing additional ports and 10 requiring laparotomy. Intraoperative complications included common bile duct injury in 1 patient (0.07%) and right hepatic artery injury in 1 patient (0.07%), with no other organ injury. Postoperative Clavien-Dindo 3 or higher complications were observed in 18 patients (1.2%). Incisional hernias occurred in 15 patients (1.0%). The median postoperative hospital stay was 3 days.

CONCLUSION

This study showed that SILC can be performed safely without any increase in complications, as reported previously. Granted that it is performed safely, SILC may be a useful technique due to its superior cosmetic outcomes or pain reduction.

Laparoscopic mesh removal for mesh infection related to pararectal incision of previous appendectomy after laparoscopic total extraperitoneal inguinal hernia repair: A case report

A 67-year-old man with a history of appendectomy 40 years ago underwent single-incision laparoscopic surgery for total extraperitoneal inguinal hernia repair. Postoperatively, the pararectal incisional scar obtained from the appendectomy was infected; thus, antibiotic therapy and drainage were performed. However, the infection persisted. After 5 postoperative months, the mesh was laparoscopically removed at a sufficient distance from the infected site. No enterocutaneous fistula was observed. After 1 year and 10 months, no recurrence of hernia or infection was observed. Thus, laparoscopic mesh removal is feasible. Infection of a 40-year-old incision rarely results in mesh infection. Therefore, in pararectal incision, the extent of mesh coverage should be considered; if the overlap is large, changing the technique by not covering the incision may be necessary.

[Effect of Endoscopic Resection on Prognosis in T1b Colorectal Cancer]

With the advancement of endoscopic resection(ER)of colorectal cancer, surgical resection after ER has been increasing. This study evaluated the effects of initial ER on short- and long-term outcomes in T1b colorectal cancer. This retrospective cohort study enrolled patients with pathological T1b colorectal cancer who underwent colorectal surgical resection between 2008 and 2018. A total of 239 eligible patients were divided into 2 groups: patients initially treated using surgical resection with lymph node dissection(LND)(surgery alone, n=142)and patients treated using initial ER and additional surgical resection with LND(surgery after ER, n=97). No significant differences were observed in short-term outcomes(ie, operative time, blood loss, or postoperative complications)or the long-term outcomes(ie, recurrence rate, overall survival rate, or recurrence free survival rate)between groups.

Circulating MicroRNAs in Gastrointestinal Cancer

Simple Summary

The screening methods and therapeutic strategies for gastrointestinal cancer (GIC) have improved, but mortality in GIC patients remains high. Early detection and precise evaluation of GIC are required to further improve treatment outcomes in GIC patients. MicroRNAs (miRNAs), which do not encode proteins, have attracted attention as biomarkers of various diseases. Since the first report revealing the strong correlation between miRNAs and cancer in 2002, numerous studies have illustrated the changes in the expression and the biological and oncological effects of miRNAs in GIC. Furthermore, miRNAs circulating in the blood are reported to be associated with GIC status. These miRNAs are thought to be useful as noninvasive biomarkers because of their stability in blood. Herein, we discuss the potential of miRNAs as noninvasive biomarkers for each type of GIC on the basis of previous reports and describe perspectives for their future application.

Abstract

Gastrointestinal cancer (GIC) is a common disease and is considered to be the leading cause of cancer-related death worldwide; thus, new diagnostic and therapeutic strategies for GIC are urgently required. Noncoding RNAs (ncRNAs) are functional RNAs that are transcribed from the genome but do not encode proteins. MicroRNAs (miRNAs) are short ncRNAs that are reported to function as both oncogenes and tumor suppressors. Moreover, several miRNA-based drugs are currently proceeding to clinical trials for various diseases, including cancer. In recent years, the stability of circulating miRNAs in blood has been demonstrated. This is of interest because these miRNAs could be potential noninvasive biomarkers of cancer. In this review, we focus on circulating miRNAs associated with GIC and discuss their potential as novel biomarkers.

Clinical outcomes of single-site laparoscopic interval appendectomy for severe complicated appendicitis: Comparison to conventional emergency appendectomy

AIM

Single-site laparoscopic interval appendectomy (SLIA) for severe complicated appendicitis after conservative treatment (CT) to ameliorate inflammation and eradicate the abscess should be safer and less invasive than emergency appendectomy (EA). However, only a few reports have been published regarding SLIA.

METHODS

We retrospectively collected data on 264 consecutive patients admitted to Kinan Hospital for treatment of appendicitis between 2012 and 2018. The safety and feasibility of SLIA and its perioperative outcomes for severe complicated appendicitis were investigated.

RESULTS

A total of 61 patients were included in this study, 25 of whom underwent CT and 36 EA. Among the 25 patients who underwent CT, 23 (92.0%) succeeded; a total of 16 patients (69.5%) underwent SLIA. Compared to the EA group, the SLIA group had less bleeding (median volume 8.5 vs 50 mL, P = .005) and lower rate of expansion surgery (0% vs 27.8%, P = .022). Although the postoperative hospital stay was shorter in the SLIA group than in the EA group (9 vs 12 days, P = .008), the total hospital stay, including the CT period, was longer in the SLIA group than in the EA group (24 vs 12 days, P < .001).

CONCLUSION

SLIA is safe, feasible, and less invasive than EA and may provide the advantages of minimally invasive surgery even if appendicitis is severe. SLIA may be a promising option for complicated appendicitis in select cases despite its disadvantage of prolonging the hospital stay.

[Carcinoma of the Ascending Colon Showing Rapid Progression of Disseminated Carcinomatosis of the Bone Marrow-Report of a Case]

A 72-year-old man with ascending colon cancer was admitted to our hospital. Right hemicolectomy and lymph node dissection(D3)were performed. The pathological diagnosis was signet-ring cell carcinoma, T4a(SE), N2b, M1a(LYM), Stage Ⅳ, R0, Cur B. Capecitabine was administered after surgery. Subcutaneous bleeding, thrombocytopenia, and a rapid increase in tumor marker levels occurred 9 months after surgery. He had already developed disseminated intravascular coagulation and was admitted to our hospital immediately. CT scan revealed metastasis in the thoracic vertebrae. Bone scintigraphy demonstrated multiple abnormal areas of uptake in the costal bones and the thoracic and lumber vertebrae. We made a final diagnosis of disseminated carcinomatosis of the bone marrow by histopathological examination. Unfortunately, before starting chemotherapy, his general condition deteriorated, and he died 14 days after hospitalization. We present here a case of colon cancer with disseminated carcinomatosis of the bone marrow.

[Super-Elderly Recurrent Rectal Cancer Effectively Treated with Chemotherapy for Three Years - Report of a Case]

The safety and feasibility of the chemotherapy for super-elderly patients over 85 years old have not been clarified yet. We report an extremely aged patient with recurrent rectal cancer that was successfully treated with chemotherapy. A 85-year-old woman underwent Hartmann procedure for rectal cancer. Nine months after surgery, CT scan revealed liver metastases in S5 and S7. We administered capecitabine plus bevacizumab chemotherapy. Liver metastases were disappeared after 6 courses. Although grade 2 hypertension was appeared, no other adverse event occurred. However, due to lung metastases, we attempted irinotecan plus bevacizumab as second line treatment. After 10 courses, general fatigue was gradually developed, so we changed the frequency of chemotherapy from biweekly to triweekly administration. The patient's performance status score has been kept 0, and she has been under treatment as an outpatient for 3 years. The chemotherapy for extremely aged patients with recurrent colorectal cancer was suggested to be safe and feasible under the adequate dose reduction and interval adjustment.

Expression of carbonic anhydrase IX is associated with poor prognosis through regulation of the epithelial‑mesenchymal transition in hepatocellular carcinoma

Carbonic anhydrase 9 (CA9) is a plasma membrane-associated isoenzyme that catalyzes pH regulation under hypoxic conditions. CA9 is transcriptionally regulated by hypoxia-inducible factor 1. Recent studies reported that hypoxia also promoted the epithelial-mesenchymal transition (EMT) in various cancers. In the present study, we evaluated the relationship between CA9 expression and EMT in vitro with two hepatoma cell lines. We also examined the clinical significance of CA9 expression in 117 consecutive patients that underwent hepatectomies for hepatocellular carcinoma (HCC). We evaluated CA9 expression and EMT induction under hypoxia with quantitative RT-PCR, western blot analysis and immunofluorescence staining, in HuH7 and HepG2 cells. We knocked down CA9 expression with small interfering RNA to evaluate the relationship between CA9 and EMT. We found that hypoxia induced CA9 expression in HCC cells and promoted EMT, evidenced by a loss of E-cadherin and an increase in N-cadherin. Twist, a transcriptional regulator of EMT, was also upregulated with hypoxia. The CA9 deficiency attenuated hypoxia-induced changes in E-cadherin and N-cadherin. Immunohistochemical evaluations of patient samples showed that CA9 was expressed in 50.4% of patients (59/117). However, patients with and without CA9 expression were not significantly different in clinicopathological factors. Nevertheless, a multivariate analysis showed that CA9 expression was an independent factor for both recurrence and prognosis among patients that underwent curative surgery for HCC. In conclusion, this study revealed that CA9 expression was a pivotal predictive factor for poor prognosis after radical surgery for HCC. Moreover, the CA9 regulation of the expression of EMT-related molecules represented a mechanism that enhanced malignant potential.

[Clinical evaluation of the risk factors for liver abscess after TACE or RFA]

Radiofrequency ablation(RFA)and transcatheter arterial chemoembolization (TACE) are widely enforced as a standard combined therapy for liver cancer. Liver abscess occurs occasionally as a complication. This clinical study was conducted to determine risk factors for liver abscess. We investigated the clinical background of 10 cases complicated by liver abscess in 957 cases of patients who underwent TACE or RFA for liver cancer at Minoh City Hospital between April 2002 and March 2012. Risk factors for liver abscess were analyzed statistically in comparison to a control group without liver abscess. Diabetes and a history of biliary tract organic disease were statistically significant independent risk factors determined by multivariate analysis. We consider patients with a history of biliary tract organic disease, or who have a potential biliary tract infection, and diabetes, to be susceptible to infection. A case presenting with diabetes and a history of biliary tract disease is in a high-risk group, so treatment with TACE or RFA for such cases should be considered carefully.

[Long-term survival in a case of advanced hepatocellular carcinoma with tumor thrombus in the portal vein and the right atrium (vp4,vv3 ) treated successfully with multidisciplinary therapies]

The prognosis for hepatocellular carcinoma (HCC) with severe vascular invasion is dismal. Surgery alone is not enough to control recurrence. Here, we report long-term survival in a case of HCC with tumor thrombus in the portal vein and right atrium, which was successfully treated through multidisciplinary therapies including surgery. The patient, a 74-year-old man, had undergone several rounds of local ablation and transarterial chemoembolization for HCC recurrence, in another hospital. He was referred to us for recurrent HCC with vascular invasion in July 2011. An abdominal computed tomography (CT) revealed a mass lesion(4 cm in diameter)in the left hepatic lobe. It also detected a tumor thrombus in the main trunk of the portal vein (Vp4), and in the right atrium (Vv3). Consequently, the patient underwent an extended left lobectomy and removal of the tumor thrombus in the portal vein and right atrium. Subsequently, fluorouracil (FU) arterial infusion and interferon therapy (FAIT) was initiated, and followed with sorafenib administration. However, multiple recurrent lesions were found in the liver, lungs, and lymph nodes. The dose of sorafenib was increased and maintained for 10 months. So far, the patient has been alive for 35 months after the operation.

[Long-term survival after surgical resection of a cancer of unknown primary site-a case report]

We report a case of long-term survival after combination chemotherapy and surgical resection of a cancer of unknown primary site[ CUPs]. A septuagenarian female was identified as having high blood levels of carcinoembryonic antigen (CEA) during follow-up monitoring of asthma. Endoscopy and imaging studies including computed tomography (CT) and positron emission tomography (PET)-CT revealed a malignant lymph node adjacent to the abdominal aorta; however, no other lesion was detected. Therefore, we performed CT-guided biopsy and diagnosed the lesion to be a lymph node metastasis of poorly differentiated adenocarcinoma. As we considered this as a systemic disease, the patient received 2 courses of combination chemotherapy with 5-fluorouracil( 5-FU)/cisplatin( CDDP) and achieved a partial response (PR). Later, the patient received S-1 therapy as second-line chemotherapy and S-1/irinotecan( CPT-11) as third-line chemotherapy in an outpatient clinic. However, the tumor continued to grow, and therefore, we decided to perform surgical resection. Histopathological examination of the resected specimen yielded a diagnosis of metastatic adenocarcinoma of the lymph node. The patient has been well without any signs of recurrence for more than 9 years since surgery. As CUPs is generally associated with poor prognosis, this case raises the possibility that combination therapy might improve convalescence.

[Long-term survival of a patient with locally advanced unresectable pancreatic cancer treated with gemcitabine after chemoradiation therapy]

We report a case of long-term survival of a patient with locally advanced unresectable pancreatic cancer treated with gemcitabine after chemoradiation therapy( CRTx). A 61-year-old woman was diagnosed as having locally advanced unresectable pancreatic cancer, 3.0 cm in diameter, which had invaded the superior mesenteric artery by computed tomography (CT). She was treated with CRTx( gemcitabine[ GEM] at 250 mg/m2/week for 6 weeks+liniac irradiation of 50.2 Gy) followed by systemic chemotherapy (gemcitabine (GEM) at 1,000 mg/m2). Reassessment after CRTx yielded a diagnosis of stable disease (according to the Response Evaluation Criteria in Solid Tumors [RECIST] 1.1). To date, the patient has undergone 57 courses of chemotherapy in the outpatient clinic; however, she did require biliary stent placement because of occlusive jaundice.

[Two case reports of neuroendocrine cell carcinoma of the stomach]

We encountered 2 cases of endocrine cell carcinoma of the stomach. One patient had a type 3 tumor in the cardia, and the other patient had a submucosal tumor in the posterior wall of the gastric angle, both of which were detected by upper gastrointestinal endoscopy. The first patient underwent total gastrectomy(D1+No.7, 19) with cholecystectomy. Microscopic histological examination fortuitously revealed a tumor thrombus in the vessel of the gallbladder. Eight months after the operation, a paraaortic lymph node recurrence was detected, and the patient died 28 months after the operation. The second patient underwent distal gastrectomy, cholecystectomy, S5 subsegmental hepatectomy, and S8 radiofrequency ablation(RFA). Despite undergoing adjuvant chemotherapy[irinotecan(CPT-11)/cisplatin(CDDP)], multiple liver recurrences were detected 6 months after the operation. Consequently, systemic chemotherapy (S-1/CDDP) was performed.

[Utility of the WallFlexTM duodenal stent for unresectable advanced gastric cancer related to gastric outlet obstruction]

Duodenal stenting for malignant disease related to gastric outlet obstruction(GOO) has been covered by health insurance in Japan since April 2010. We inserted WallFlexTM duodenal stents(WDS) in 4 patients with GOO caused by unresectable gastric cancer. WDS insertion was successful in all 4 cases. Duodenal perforation occurred in 1 case. One case each of stent obstruction and stent migration occurred. All patients could eat a soft-food diet for 3-6 months (median, 5.3 months). Survival time ranged between 5 and 14 months (median, 6 months). Three patients underwent S-1 combination chemotherapy. Duodenal stenting is expected to be effective for advanced gastric cancer related to GOO.

[A case report of long-term survival of endocrine cell carcinoma of the esophagus with chemo-radiation therapy]

The patient was an 84-year-old man, who was diagnosed with cT3N2 (101L, 109L) M0, stage III esophageal cancer. The tumor, immunohistochemically, was stained positive for CD56 and NSE yielding a definitive diagnosis of endocrine cell carcinoma of the esophagus. We selected chemo-radiation therapy (5-FU/CDDP and 2 Gy/day total 60 Gy) for this patient. As adjuvant chemotherapy, 7 courses of chemotherapy with 5-FU/CDDP, was performed. At 8 months from the chemo-radiation therapy, the disease was diagnosed as cCR. But two years later, lung metastasis appeared, so we started chemotherapy with docetaxel/CDDP/5-FU. After 2 courses, lung metastasis was almost disappeared. He has been survived for four years and five months after chemo-radiation. This case suggests that chemo( FP) -radiation therapy and adjuvant chemotherapy could be an effective treatment for endocrine cell carcinoma of the esophagus.

[A case of S-1/CDDP chemotherapy for inoperable advanced gastric cancer which led to gastrectomy with histological complete response]

As the treatment for inoperable advanced gastric cancer, S-1/CDDP combination therapy (SP chemotherapy) has become a standard treatment. In our hospital, a second course of chemotherapy was performed on an outpatient basis in order to improve a traditional QOL. In this case, it showed remarkable effects in 15 months after starting chemotherapy. Then gastrectomy was performed. Histological findings of the resected specimens confirmed pCR in all tumors. We report on progress of this case and explain about the ingenuity of SP chemotherapy.

[Study on evaluating methods for the quality control of glycoprotein products. (III)--Erythropoietin products. Part 3]

We reported previously that peptide mapping using high-performance liquid chromatography with electrospray ionization mass spectrometry (LC/MS) and liquid chromatography with tandem mass spectrometry (LC/MS/MS) are useful for determination of the glycosylation sites, carbohydrate structure, and site-specific carbohydrate heterogeneity of glycoproteins. Here, with intention to enhance the sensitivity and shorten the time-span of analysis to characterize glycoproteins, especially biotechnological products with carbohydrate moieties, we studied the introduction of HPLC with a microbore column to LC/MS with recombinant erythropoietin (rh-EPO). In addition, we evaluated the ability of LC/MS/MS precursor-ion scanning to make identification of glycopeptides and facilitate the analysis of carbohydrate moieties. We found that the peptide mapping with microbore HPLC is highly sensitive and more rapid than the previous method, and the precursor-ion scanning is helpful for identifying glycopeptides. Our results indicate that these methods are very useful for characterization and quality control of the carbohydrate moieties of biotechnological products.

[Rapid quantitation of follistatin by surface plasmon resonance (SPR) immunoassay]

A simple, rapid, and accurate assay using surface plasmon resonance (SPR) apparatus with anti-follistatin antibody (SPR immunoassay) has been developed for the quantitation of recombinant follistatin. This assay can be performed with a direct injection of conditioned medium; results were obtained within 10 min. The quantitation component of this assay was precise and accurate with a limit of quantitation of 62.5 ng/ml in Ham's F12 medium containing 2% fetal bovine serum. These results demonstrate that SPR immunoassay is a powerful technique for several researches, especially for screening of gene transfectant and monitoring of protein production.

Structural analysis of sulfated N-linked oligosaccharides in erythropoietin

We previously demonstrated that high-performance liquid chromatography with electrospray ionization mass spectrometry (LC/MS) equipped with a graphitized carbon column (GCC) is useful for the structural analysis of carbohydrates in glycoproteins. Using LC/MS with GCC, sulfated N-linked oligosaccharides were found in erythropoietin (EPO) expressed in baby hamster kidney cells. Sulfation occurs in a part of the N-linked oligosaccharides in the EPO. Sulfated monosaccharide residue in the sulfated N-linked oligosaccharide was determined by exoglycosidase digestion followed by sugar mapping by LC/MS. The linkage position and branch-location of the sulfate group in the tetraantennary oligosaccharide were analyzed by (1)H-nuclear magnetic resonance. It was suggested that sulfation occurs on the C-6 position of GlcNAc located in the GlcNAcbeta1-4Manalpha1-3 branch.

Ganglioside GD1a inhibits HGF-induced motility and scattering of cancer cells through suppression of tyrosine phosphorylation of c-Met

We previously reported that ganglioside GD1a, which is highly expressed in poorly metastatic FBJ-S1 cells, inhibits the serum-induced motility of FBJ-LL cells and that the metastatic potential of FBJ-LL cells is completely suppressed by enforced GD1a expression (Hyuga et al., Int J Cancer 1999;83:685-91). We recently discovered that hepatocyte growth factor (HGF) induces FBJ-LL cell motility. In the present study, the HGF-induced motility of FBJ-S1 cells was found to be one-thirtieth that of FBJ-LL cells. This motility of GD1a-expressing transfectants, which were produced by transfection of FBJ-LL cells with GM2/GD2 synthase cDNA, decreased with increases in their GD1a expression and HGF induced almost no motility in GD1a-pretreated FBJ-LL cells, indicating that GD1a inhibits the HGF-induced motility of FBJ-LL cells. The expression of the HGF receptor c-Met on FBJ-S1 cells, FBJ-LL cells, transfectants and a mock-transfectant was almost the same. The level of tyrosine phosphorylation of c-Met after HGF stimulation in FBJ-S1 cells, GD1a-pretreated FBJ-LL cells and a GD1a-expressing transfectant was significantly lower than in FBJ-LL cells and a mock-transfectant. These findings suggested that GD1a inhibits the HGF-induced motility of FBJ-LL cells through suppression of tyrosine phosphorylation of c-Met. HepG2 cells, a human hepatoma cell line, were used to investigate whether GD1a interferes with other cancer cells expressing c-Met. HepG2 cells did not express GD1a. HGF induced cell scattering of HepG2 cells and the scattering was inhibited by pretreating the cells with GD1a. The c-Met in the cells was autophosphorylated by stimulation with HGF, but after treating the cells with GD1a, the HGF-induced autophosphorylation of c-Met was suppressed. These results suggest that GD1a acts as a negative regulator of c-Met in cancer cells.

Selective glycopeptide mapping of erythropoietin by on-line high-performance liquid chromatography--electrospray ionization mass spectrometry

Selective glycopeptide mapping of recombinant human erythropoietin (rhEPO) used as a model glycoprotein was successfully carried out by on-line high-performance liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS) using a Vydac C18 column eluted in acetonitrile-1 mM ammonium acetate, pH 6.8. rhEPO expressed in a Chinese hamster ovary clone was exhaustively digested into four glycopeptides and nine peptides with endoproteinase Glu-C. Both glycopeptides and peptides were eluted with trifluoroacetic acid as the eluent, whereas only glycopeptides were eluted selectively with ammonium acetate in the following order: N38, N24, 0126, and N83. Furthermore, many glycoforms included in each glycopeptide were found to be separated by differences in the numbers of sialic acid and N-acetyllactosaminyl repeats. Twenty, 16 and 22 different N-linked oligosaccharides were determined at Asn24, 38, and 83, respectively, and two different O-linked oligosaccharides were observed at Ser126. Our method is simple, rapid, and useful for determining the carbohydrate structures at each glycosylation site and for elucidating the site-specific carbohydrate heterogeneity.

Application of liquid chromatography/mass spectrometry and liquid chromatography with tandem mass spectrometry to the analysis of the site-specific carbohydrate heterogeneity in erythropoietin

High-performance liquid chromatography with electrospray ionization mass spectrometry (LC/MS) and liquid chromatography with tandem mass spectrometry (LC/MS/MS) were applied to the analysis of the site-specific carbohydrate heterogeneity in erythropoietin (EPO) used as a model of the sialylated glycoprotein. N-linked oligosaccharides were released from recombinant human EPO expressed in Chinese hamster ovary cells enzymatically and reduced with NaBH(4). Many different sialylated oligosaccharides of EPO were separated and characterized by LC/MS equipped with a graphitized carbon column (GCC). Glycosylation sites and the preliminary glycosylation pattern at each glycosylation site were determined by LC/MS of endoproteinase Glu-C-digested EPO. The detailed site-specific carbohydrate heterogeneity caused by the differences in the molecular weight, branch, linkage, and sequence was elucidated by GCC-LC/MS of the N-linked oligosaccharides released from the isolated glycopeptides. Structural details of the isomers were analyzed by LC/MS/MS, and it was indicated that di- and trisialylated tetraantennary oligosaccharides are attached to Asn24, 38, and 83, whereas their isomers, di- and trisialylated triantennary oligosaccharides containing N-acetyllactosamines, are combined with Asn24. Our method is useful for the determination of glycosylation sites, the site-specific carbohydrate heterogeneity of glycoproteins, and the carbohydrate structure.

Possible role of hepatocyte growth factor/scatter factor and activin A produced by the target organ in liver metastasis

The molecular mechanism of organ-specific metastasis to the liver remains largely unknown. However, it is conceivable that paracrine growth factors produced by a target organ induce migration and proliferation of malignant cells to that organ, and this is the cause of organ-specific metastasis. In this study, we investigated the effect of hepatocyte growth factor/scatter factor (HGF/SF) and activin A, which are known to be produced by the liver, on the motility and growth of liver-metastatic cell line FBJ-LL. HGF/SF and activin A induced motility synergistically, but they did not affect the proliferation of FBJ-LL cells. Expression of the HGF/SF receptor, the c-met gene, and the activin-receptor type IA, type IB, and type IIA genes in FBJ-LL cells was detected by reverse transcription polymerase chain reaction. These findings suggest that both HGF/SF and activin A promote organ-specific metastasis to the liver by induction of migration through their specific receptors on liver-metastatic cells.

Suppression by ganglioside GD1A of migration capability, adhesion to vitronectin and metastatic potential of highly metastatic FBJ-LL cells

Ganglioside GD1a, which is highly expressed in poorly metastatic FBJ-S1 cells, has been shown to inhibit the serum-induced migration capability of highly metastatic FBJ-LL cells. In the present study, the capacity of FBJ-S1 cells to adhere to vitronectin was found to be about half that of FBJ-LL cells. Pre-treatment of FBJ-LL cells with GD1a decreased this capacity by 30% that of the control, whereas GM1-pre-treatment caused only a 10% decrease, indicating that GD1a specifically inhibits FBJ-LL cell adhesion to vitronectin. Since FBJ-LL cells contain almost no GD1a, transfectants capable of expressing GD1a to varying degrees were produced in this study by transfection of FBJ-LL cells with GM2/GD2-synthase cDNA. Decrease in the serum-induced migration capacity of these transfectants was accompanied by an increment in GD1a expression. Adhesion of the transfectants to vitronectin decreased by 30% as compared with mock-transfected cells. Within 4 to 5 weeks after GD1a-expressing transfectant and mock-transfected cells were transplanted into mice, metastatic nodules were observed in liver, lung, kidney and adrenal glands of mock-transplanted mice, but not in those with GD1a-expressing transfectants, indicating that GD1a suppresses the metastasis of FBJ-osteosarcoma cells, possibly by inhibiting cell migration and cell adhesion. The involvement of the ganglioside in the suppression of metastasis is clearly demonstrated in the present study.

Analysis of carbohydrate heterogeneity in a glycoprotein using liquid chromatography/mass spectrometry and liquid chromatography with tandem mass spectrometry

High-performance liquid chromatography with on-line electrospray ionization mass spectrometry (ESI-LC/MS) was investigated for the analysis of carbohydrate heterogeneity using RNase B as a model glycoprotein. Oligosaccharides released from RNase B with endoglycosidase H were reduced and separated on a graphitized carbon column (GCC). GCC-HPLC/MS in the positive-ion mode was successful in the identification of one Man5GlcNAc, three Man6GlcNAc, three Man7GlcNAc, three Man8GlcNAc, one Man9GlcNAc, and an oligosaccharide having six hexose units (Hex) and two N-acetylhexosamine units (HexNAc). The branch structures of the three Man7GlcNAc isomers were determined by liquid chromatography with tandem mass spectrometry (LC/MS/MS). LC/MS/MS analysis was shown to be useful for the detection and identification of a trace amount of Hex6HexNAc2 alditol as a hybrid-type oligosaccharide. Its structure was confirmed by the combination of LC/MS with enzymatic digestion using beta-galactosidase and N-acetyl-beta-glucosaminidase. The relative quantities of high-mannose-type oligosaccharides in RNase B detected by ESI-LC/MS are in reasonable agreement with those by UV, high-pH anion-exchange chromatography with pulsed amperometric detection, fluorophore-assisted carbohydrate electrophoresis. Our results indicate that LC/MS and LC/MS/MS can be utilized to elucidate the distribution of oligosaccharides and their structures, which differ in molecular weight, sugar sequence, and branch structure.

[Study on evaluating methods for the quality control of glycoprotein products. (II)--Erythropoietin products. Part 2]

Using recombinant human erythropoietin (rh-EPO) from three different sources, the usefulness of HPAEC-PAD (high-pH anion exchange chromatography with pulsed amperometric detection) for evaluation of carbohydrate moieties of rh-EPO products was evaluated. It is well known that in vivo bioactivity and metabolic fate of EPO are dependent on the number of sialic acids and the degree of branching in the carbohydrate moieties. Here we show that HPAEC analysis reveals differences in the number of sialic acids as well as in the structure of desialylated N-glycans among the rh-EPO products. Therefore, HPAEC is useful for evaluation of the quality of rh-EPO products.

Inhibition of highly metastatic FBJ-LL cell migration by ganglioside GD1a highly expressed in poorly metastatic FBJ-S1 cells

For clarification of the functions of gangliosides on tumor metastasis, examination was made of the ganglioside patterns of poorly metastatic FBJ-S1 and highly metastatic FBJ-LL cells. FBJ-S1 cells expressed GM3 and GD1a, whereas FBJ-LL cells expressed GM3 and slightly expressed GD1a. The capacity for FBJ-LL cells to migrate was ten times that of FBJ-S1 cells, but decreased by a half by pretreatment with GD1a. GD1b or GT1b had the same effect as GD1a, and synthetic sialyl compounds to a lesser extent, suggesting that gangliosides contain more than two sialyl residues to inhibit the migration of FBJ-LL cells.

Involvement of transforming growth factor beta1 in autocrine enhancement of gelatinase B secretion by murine metastatic colon carcinoma cells

We have reported previously that highly metastatic LuM1 cells derived from colon carcinoma colon 26 secrete larger amounts of gelatinase B than NM11 cells with poor metastatic potential, and that an increase in this gelatinase B secretion can be induced by autocrine factors (Hyup et A, Cancer Res., 54: 3611-3616, 1994). In the present study, a partial characterization was achieved by comparison of the autocrine factor preparation (fraction G) from serum-free medium conditioned with metastatic LuM1 cells with soluble factors known to stimulate gelatinase B secretion. Secretion of gelatinase B by LuM1 cells was augmented by tumor necrosis factor alpha, transforming growth factor beta1 (TGF-beta1), interleukin 1beta, or epidermal growth factor, and specific neutralizing antibodies abolished the induced increases. Platelet-derived growth factor and insulin-like growth factor 1 had no effect on gelatinase B secretion by LuM1 cells. The enhancement of gelatinase B secretion by fraction G was partially inhibited by the antibody to TGF-beta1. TGF-beta1 was detected in both active and latent forms in serum-free medium conditioned with LuM1 or NM11 cells, with the amount of TGF-beta1 higher in the former case. Gelatinase B secretion by LuM1 cells was enhanced by the addition of TGF-beta1 to the culture medium, but that by NM11 cells was not seriously affected, although the latter bound more of the factor. These results indicate the involvement of this growth factor in the autocrine stimulation of gelatinase B secretion by LuM1 cells. However, the autocrine factor effect was not fully explained by TGF-beta1 in the medium, and the involvement of some other unknown factor(s) was thus indicated.

Autocrine factor enhancing the secretion of M(r) 95,000 gelatinase (matrix metalloproteinase 9) in serum-free medium conditioned with murine metastatic colon carcinoma cells

We previously reported that murine tumor cells with a high spontaneous metastatic potential to the lung secrete higher amounts of M(r) 95,000 gelatinase (matrix metalloproteinase 9, MMP9) than do poorly metastatic cells. The present study, conducted to clarify the mechanisms underlying the increase in MMP9, revealed an autocrine factor that enhances the secretion of M(r) 95,000 gelatinase (MMP9). The secretion of MMP9 by highly metastatic colon carcinoma LuM1 cells, detected by zymography, was augmented 10-fold when cultured in medium supplemented with serum-free medium conditioned with LuM1 cells. Because the secretion of M(r) 60,000 gelatinase (MMP2), as well as total protein, by the same cells was not affected under these conditions, the augmentation appears specific for MMP9. The steady-state level of MMP9 mRNA was elevated in LuM1 cells cultured in the presence of the supernatant. The amount of the factor in the culture medium increased with time in culture, indicating that it was produced by the LuM1 cells. It was found to be heat stable but sensitive to trypsin digestion. Conditioned medium from poorly metastatic NM11 cells did not stimulate the secretion of gelatinases by NM11 cells, suggesting that autocrine stimulation of MMP9 secretion is a characteristic of metastatic cells. This factor could account for the augmented secretion of MMP9 by murine tumor cells with spontaneous metastatic potential to the lung.