Frequent loss of RUNX3 gene expression in remnant stomach cancer and adjacent mucosa with special reference to topography

Our previous studies suggest that a lack of RUNX3 function is causally related to the genesis and progression of human gastric cancer. This study was conducted to determine whether alteration of RUNX3 gene expression could be detected in the normal-looking gastric remnant mucosa, and to ascertain any difference in the potential of gastric carcinogenesis between the anastomotic site and other areas in the remnant stomach after distal gastrectomy for peptic ulcer (RB group) or gastric cancer (RM group), by analysing RUNX3 expression with special reference to topography. A total of 89 patients underwent distal gastrectomy for gastric cancer from the intact stomach (GCI group) and 58 patients underwent resection of the remnant stomach for gastric cancer (RB group: 34 cases, RM group: 24 cases). We detected RUNX3 and gene promoter methylation by in situ hybridisation, quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), and methylation-specific PCR. The interval between the initial surgery and surgery for remnant gastric cancer (interval time) was 10.4 years in the RM group, and 27.5 years in the RB group. Cancers in the RB group were significantly more predominant in the anastomosis area (P<0.05). Within the tumour, downregulation of RUNX3 expression ranged from 74.7 to 85.7% in the three groups. The rate of downregulation of RUNX3 of adjacent mucosa was 39.2% (11 in 28 cases) in RB and 47.6% (10 in 21 cases) in RM, which are significantly higher than that of the GCI group (19.5%, 17 in 87 cases). In noncancerous mucosa of the remnant stomach in the RB group, RUNX3 expression decreased more near the anastomosis area. In the RM group, however, there were no significant differences in RUNX3 expression by sampling location. Based on RUNX3 downregulation and clinical features, residual stomach mucosa of the RM group would have a higher potential of gastric carcinogenesis compared to the RB or GCI group. Gastric stump mucosa of the RB group has higher potential especially than other areas of residual stomach mucosa. Measurement of RUNX3 expression and detection of RUNX3 methylation in remnant gastric mucosa may estimate the forward risk of carcinogenesis in the remnant stomach.

Frequent downregulation of the runt domain transcription factors RUNX1, RUNX3 and their cofactor CBFB in gastric cancer

Our previous studies suggest that lack of RUNX3 function is causally related to the genesis and progression of human gastric cancer, but potential roles of other members of the RUNX family genes have not yet been reported. We examined the expression of 3 Runt-related (RUNX) genes, RUNX1, RUNX2 and CBFB, in gastric cancer cell lines and primary gastric cancer specimens and compared them to those of RUNX3 reported earlier in conjunction with clinicopathologic factors. Expression of RUNX family genes in 9 gastric cancer cell lines, 56 primary gastric cancer specimens and surrounding normal gastric mucosa were estimated by Northern blot analysis, quantitative RT-PCR and in situ hybridization. Northern blot analysis in gastric cancer cell lines showed downregulation of RUNX1 and RUNX3 in 67% and 78% of the cell lines tested, respectively. The ratio of the average RUNX mRNA/beta-actin mRNA ratio (x10(3)) for RUNX1 was 48.0 +/- 21.1 vs. 21.4 +/- 8.1; RUNX2, 1.1 +/- 0.3 vs. 1.0 +/- 0.2; RUNX3, 9.2 +/- 6.3 vs. 3.1 +/- 1.3 and CBFB, 42.0 +/- 19.4 vs. 21.0 +/- 8.4 (normal vs. tumor, respectively, average +/-SD). The basal RUNX2 expression was very weak, and there was no significant change in gastric cancers. Both RUNX1 and RUNX3 showed remarkable downregulation in 62% and 69%, respectively, of surgically resected specimens compared to surrounding mucosa analyzed by quantitative RT-PCR (p < 0.01). Furthermore, CBFB, the gene encoding the cofactor of RUNX1, -2, -3, was also downregulated in significant fraction (32%, p < 0.05). The percentage of downregulation of RUNX1, RUNX3 and CBFB increased as the cancer stage progressed. Tricostatin A and 5'-azacitidin reactivate RUNX3 expression, but they could not reactivate expression of RUNX1 and CBFBeta in gastric cancer cells, suggesting that the downregulation was due to mechanisms other than methylation of the promoter region. These findings suggest that RUNX1 and CBFBeta in addition to RUNX3 play some roles in gastric cancers and that roles of RUNX gene family in gastric cancer are more widespread and complex than previously realized.

Characteristics of gastric carcinoma invading the muscularis propria

BACKGROUND

Although gastric carcinomas invading the muscularis propria (mp) are classified among advanced-stage cancers in Japan, postoperative survival has been reported to approximate that in early gastric carcinoma. Characteristics of gastric carcinomas invading the mp, therefore, were compared to carcinomas invading only the mucosa (m) or submucosa (sm), and to those invading the subserosa (ss) or serosa (se).

METHODS

We retrospectively compared clinicopathologic findings, prognosis, and cause of death in patients with gastric carcinoma invading mp to those showing the other levels of invasion.

RESULTS

Patients with carcinomas invading the mp had larger tumors and more frequent lymph node and hematogenous metastases than those with carcinomas invading only m or sm. Yet they had smaller tumors and less frequent lymph node or peritoneal metastasis than those with carcinomas invading ss or se. Postoperative survival with tumors invading the mp was intermediate between that with carcinoma invading only m or sm and that with subserosal or serosal invasion. Causes of death with tumors invading muscularis were similar to those with carcinomas invading only m or sm.

CONCLUSIONS

Characteristics of gastric carcinoma invading the mp are intermediate between those of early and advanced carcinoma.

Differential gene expression profiles of radioresistant oesophageal cancer cell lines established by continuous fractionated irradiation

Radiation therapy is a powerful tool for the treatment of oesophageal cancer. We established radioresistant cell lines by applying fractionated irradiation in order to identify differentially expressed genes between parent and radioresistant cells. Six oesophageal cancer cell lines (TE-2, TE-5, TE-9, TE-13, KYSE170, and KYSE180) were treated with continuous 2 Gy fractionated irradiation (total dose 60 Gy). We compared expression profiles of each parent and radioresistant lines on a cDNA microarray consisting of 21168 genes. In the fractionated irradiation trial, four radioresistant sublines (TE-2R, TE-9R, TE-13R, KYSE170R) were established successfully, and we identified 19 upregulated and 28 downregulated genes common to radioresistant sublines. Upregulated genes were associated with apotosis and inflammatory response (BIRC2 and COX-2), DNA metabolism (CD73), and cell growth (PLAU). Downregulated genes were associated with apoptosis (CASP6), cell adhesion (CDH1 and CDH3), transcription (MLL3), and cell cycle (CDK6). Some of these genes were known to be associated with radiation response, such as COX-2, but others were novel. Reverse transcription–polymerase chain reaction confirmed that genes selected by cDNA microarray were overexpressed in clinical specimens of radioresistant cases. Global gene analysis of radioresistant sublines may provide new insight into mechanisms of radioresistance and effective radiation therapy.

[Nobel genes improve accuracy in detection of peritoneal micro-metastasis of gastric cancer to decide indication for chemotherapy]

Peritoneal metastasis is the most frequent form of recurrence for advanced gastric cancer. We previously performed a global analysis of the gene expression of gastric cancer cell lines established from peritoneal metastasis with cDNA microarray. One of the up-regulated genes is L-3 phosphoserine phosphatase (L3-PP). We have examined its potential as a novel marker for the detection of peritoneal micrometastasis of gastric cancer. L3-PP mRNA in peritoneal wash in 93 gastric cancer patients was quantified for comparison of carcinoembryonic antigen (CEA) mRNA by means of real-time RT-PCR to predict peritoneal recurrence. The quantity of L3-PP and CEA correlated with wall penetration. Eleven out of 18 cases with peritoneal dissemination were L3-PP+ (61% sensitivity). For three out of 18 cases of peritoneal dissemination, only L3-PP could detect micrometastasis of gastric cancer. Consequently, free cancer cells that cannot be detected by CEA mRNA could be detected using L3-PP mRNA. Although CEA alone was not sufficient, L3-PP and CEA in combination can attain a higher accuracy of detection.

[Efficacy of intra-peritoneal and intra-venous injection of monoclonal antibody A7-NCS conjugates against peritoneal dissemination of the gastric cancer]

The monoclonal antibody A7 (Mab A7) against human colonic cancer also reacts with human gastric cancer at a high rate. We produced a conjugate of neocarzinostatin (NCS) with Mab A7 (A7-NCS). The in vitro anticancer effect of A7-NCS on the antigen-positive human gastric cancer cell line MKN45 was stronger than that of free NCS. Nude mice models of peritoneal dissemination were established by the intra-peritoneal inoculation of MKN45. These models were divided into three groups. The anticancer effect observed in the group that received the intra peritoneal injection of A7-NCS was superior to that observed in the group that received the intra-venous injection and the group that received no treatment. In conclusion, the intra-peritoneal injection of A7-NCS was a useful treatment method for the peritoneal dissemination of gastric cancer.

[Over expression of Reg IV in peritoneal dissemination of gastric cancer]

We previously performed a global analysis of the gene expression of gastric cancer cell lines established from peritoneal dissemination (SNU-5, SNU-16, SNU-719, KATO-III and GT3TKB) with the cDNA microarray method to identify the novel markers for the detection of micro-metastasis in peritoneal cavity. One of the up-regulated genes is Reg IV, which is a member of the Reg gene family belonging to calcium dependent lectin (C-type lectin) gene superfamily. We have examined Reg IV potential as a novel marker for the detection of peritoneal micro-metastases of gastric cancer. Reg IV expression was examined in five gastric cancer cell lines established from peritoneal dissemination and compared with myeloid leukemia cell (HL60), methothelial cell lines Met5A and the other gastric cell line established from primary tumor (SNU-1) by quantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR). Reg IV was highly overexpressed in 4 gastric cancer cell lines established from peritoneal dissemination, but weakly expressed in other cell lines. According to Reg IV mRNA expression levels in surgically resected specimens, the quantity of Reg IV correlated with wall penetration. Furthermore, Reg IV mRNA expression level in the peritoneal wash from 35 gastric cancer patients was also prone to correlation with wall penetration. These results suggest that Reg IV may be involved in peritoneal dissemination of gastric cancers and Reg IV may be a potential novel marker for peritoneal dissemination of gastric cancers.

[A case of postoperative pelvic metastasis and multiple liver metastases of the rectal cancer successfully treated by arterial infusion therapy with 5-FU/leucovorin]

A 55-year-old man underwent a rectal amputation for rectal cancer in 1994. As the tumor marker was elevated in 2002, we performed an abdominal CT scan and detected local and multiple liver recurrences. We treated the patient with intra-arterial infusion of 5-FU/LV via the internal iliac artery and the hepatic artery. The chemotherapy was performed on a weekly basis; it consisted of 5-FU (500 mg/body), administered for 5 hours to bilateral reservoirs through an infusion pump and l-leucovorin (400 mg/body), administered intravenously for 2 hours. After 18 administrations of this regimen during a hospital stay and after a discharge from the hospital as an outpatient, the multiple liver metastases that were observed have disappeared. Further, the local recurrences showed a partial reduction in tumor size with a decrease in perineal pain. Subsequently, the patient did not require further doses of morphine. He exhibited no severe side effects except for grade 1 nausea, and his QOL was also good. Therefore, local intra-arterial infusion chemotherapy with 5-FU/LV appears to have been effective for rectal cancer recurrences.

[A case of unresectable multiple liver metastases from colon cancer successfully treated by hepatic arterial infusion chemotherapy and systemic immunotherapy (IFNANK) followed by hepatic resection]

The patient was a 76-year-old man, diagnosed with sigmoid colon cancer with unresectable multible liver metastases. After sigmoidectomy with D2 regional lymphnode dissection on June 21, 2002 (moderately differentiated adenocarcinoma, ss, n(-), H3, P0, M(-), Stage IV), intermittent hepatic arterial infusion chemotherapy using 5-FU (1,250 mg/body/3 hr) and CDDP (10 mg/body/30 min) was performed weekly for 23 times, and then biweekly for 15 times. The total dosages of 5-FU were 47.5 g. During the regional chemotherapy, IFNANK therapy was performed biweekly as systemic immunotherapy. As a result, serum levels of tumor markers were remarkably decreased, and the metastatic liver tumors had disappeared in the CT finding in July 2003. Thereafter, IFNANK therapy was continued without the chemotherapy. However, CT and PET detected the recurrent liver tumors in December 2003, and the tumors were curatively resected on January 28, 2004.

[Utility of dopa decarboxylase as a novel marker for the detection of peritoneal micro-metastases of gastric cancer with realtime RT-PCR]

We have examined the utility of DDC as a novel marker for the detection of peritoneal micrometastases of gastric cancer. DDC mRNA in the peritoneal wash from 114 gastric cancer patients was quantified for a comparison of carcinoembryonic antigen (CEA) mRNA by means of real-time RT-PCR with a fluorescently labeled probe to predict peritoneal recurrence. The cut-off value was set at the upper limit of the quantitative value for non-cancer patients, and those above this cut-off value constituted the micrometastasis (MM+) group. Thirteen of 15 cases with peritoneal dissemination were MM+DDC (87% sensitivity), and one of 48 t1 cases was MM+ (98% specificity). DDC levels in peritoneal washes from patients with synchronous peritoneal metastases were more than 50 times higher than in those from patients without metastasis (p<0.01). For 15 cases of peritoneal dissemination (seven cases were cytologically positive), DDC was positive in 13 cases (87% sensitivity), but CEA failed to detect micrometastases in four cases (73% sensitivity), indicating that DDC is in some cases superior to CEA for the detection of peritoneal micrometastases of gastric cancer in terms of sensitivity as well as specificity, especially for poorly differentiated adenocarcinomas. Combination of CEA and DDC improved the accuracy of diagnosis up to 93%. These results suggest that DDC is potentially a novel marker for peritoneal dissemination of gastric cancer and that quantitative RT-PCR of DDC is reliable and efficient for the selection of patients for adjuvant intraperitoneal chemotherapy to prevent peritoneal recurrence.

[A trial of the new procedure of sentinel node biopsy in the lower rectal cancer by a transsacral approach]

We describe a new method of sentinel node (SN) biopsy in the lower rectal cancer by a transsacral approach. Before the operation, an endoscopic clipping was performed around the tumor. The patient was placed in a jack knife position. A transverse incision was made over the S4-S5 joint. Subsequently, the S4-S5 joint was dissected, and the lower rectum was exposed without destroying the perirectal fatty tissue. CH-40 dye was injected into the submucosal layer of the rectal cancer. The lymph nodes that were blackened within 15 minutes were recognized to be SNs. Few investigations were reported with regard to sentinel node navigation surgery (SNNS) for lower rectal cancer, because the anatomical properties of the lower rectum make it difficult to inject the dye and recognize rectal tumors or lymph nodes. In our method, the lower rectum was exposed without destroying the perirectal fatty tissue, the dye was easily injected, and the SNs were easily found and extirpated. Our method of transsacral approach is considered to be useful.

[Intraperitoneal chemotherapy against peritoneal carcinomatosis of gastric cancer with activated carbon particles adsorbing mitomycin C for four patients]

Activated carbon particles adsorbing mitomycin C (MMC-CH) was administered to four patients with peritoneal carcinomatosis of gastric cancer into their abdominal cavities. Tumor markers of CEA, CA19-9, CA125, CA72-4 and STN were measured before and after the administration. The waist of each patient was also measured. After the administration of MMC-CH, tumor markers of three out of the four patients were decreased and a large amount of ascites of all patients had disappeared. The appetite of all four patients had increased and complaints such as nausea and vomiting had decreased. The mean survival of the four patients was 291.2 days (123-542 days). Our results suggested that MMC-CH had an anti-tumor effect of peritoneal carcinomatosis and improved the QOL of patients with a large amount of ascites.

[Fundamental studies on locally injected methotrexate bound to activated carbon particles (MTX-CH)]

We developed a new dosage formulation of methotrexate bound to activated carbon particles (MTX-CH). In this study, subcutaneous injection of MTX-CH was examined for its long-acting effect at the injection sites, anti-tumor effect and acute toxicity in mice. MTX-CH- or MTX aqueous solution (MTX-SOL)- was injected locally into tumors growing on the back of BALB/c mice at a dosage of 30 mg/kg as methotrexate (MTX). (1) The MTX concentration at the injection sites remained higher in mice with MTX-CH than that with MTX-SOL. (2) A marked effect on the control of tumor growth by MTX-CH was noted after repeated injections throughout the observation period. These results suggest that MTX-CH is superior to MTX-SOL due to longer-acting effects at the administration site and have a better control of tumor growth than MTX aqueous solution (MTX-SOL).

[Intrahepatic arterial chemotherapy with 5-fluorouracil and intramuscular interferon-alpha for a patient with diffuse type of hepatocellular carcinoma]

We report a case of diffuse type advanced hepatocellular carcinoma (HCC), which was successfully treated by a combination therapy of interferon-alpha (IFN) and 5-fluorouracil (5-FU). A 74-year-old man underwent distal gastrectomy 6 years ago for gastric cancer. In April 2002, an increased serum alpha-feto-protein (AFP) level was noted and a computed tomography (CT) of the abdomen revealed a diffuse type of HCC. He was treated with a combination therapy of IFN (5x10(6) units/body i.m., days 1, 3, 5, 8, 10, 12, 15, 17, 19, 22, 24, 26) and 5-FU (500 mg/body/day i.a., days 1-5, 8-12 continuously). The treatment was repeated every 4 weeks with a maximum of five cycles. After 5 cycles, serum AFP levels fell from 665 ng/ml to a normal level. CT showed a reduced size of the tumor. He has been well and continue to receive IFN (3x10(6) units/body i.m., two times a week) and 5-FU (500 mg/body/day i.a., once a week) at the outpatient clinic for the last 16 months.

Clinicopathologic and Prognostic Characterization of Poorly Differentiated Medullary-type Gastric Adenocarcinoma

Poorly differentiated medullary-type gastric adenocarcinoma has been reported to differ biologically from poorly differentiated scirrhous adenocarcinoma, and we have characterized the differences in greater detail. Clinicopathologic comparisons were made between the former and latter tumor types as well as well-differentiated gastric adenocarcinoma. Poorly differentiated medullary cancers were smaller, invaded less deeply, and were less likely to arise from the upper part of the stomach than scirrhous cancers. Poorly differentiated medullary cancers less often gave rise to lymph node and peritoneal metastases than scirrhous cancers but more often metastasized to the liver. Venous invasion was more common in medullary than scirrhous or well-differentiated adenocarcinomas. Postoperative survival for patients with poorly differentiated medullary cancers was significantly better than for patients with scirrhous-type cancers but did not differ significantly from survival with well-differentiated adenocarcinoma. The most common cause of death was hematogenous metastasis in patients with medullary or well-differentiated adenocarcinomas, whereas in patients with scirrhous cancer peritoneal metastasis was the most frequent cause. In conclusion, the biologic behavior of poorly differentiated medullary gastric adenocarcinoma was similar to that of well-differentiated adenocarcinoma.

Time to Death and Pattern of Death in Recurrence following Curative Resection of Gastric Carcinoma: Analysis Based on Depth of Invasion

It is difficult to predict recurrence in patients who undergo curative gastrectomy for gastric carcinoma. If the timing and site of recurrence can be predicted, it becomes easier to detect recurrent disease. Records of 290 patients who died of tumor recurrence after curative gastrectomy for gastric carcinoma were retrospectively analyzed to determine whether the depth of carcinoma invasion is independently correlated with the time to death due to tumor recurrence. Additionally, the relation between the pattern of recurrence and the depth of invasion of the gastric wall was examined. Postoperative survival in patients with tumors with deep invasion was shorter than that of patients with tumors with shallow invasion. Depth of invasion was a predictor of survival on multivariate analysis. When carcinoma invaded into deeper layers, the incidence of peritoneal metastasis and local recurrence rose and that of hematogenous metastasis fell. In conclusion, the timing of death and the site of recurrence after gastrectomy for gastric carcinoma might be predicted by the depth of invasion of the gastric wall.

Management of postoperative follow-up and surgical treatment for Krukenberg tumor from colorectal cancers

BACKGROUND/AIMS

The purpose of this retrospective study was to evaluate the clinical presentation as well as surgical intervention for ovarian metastasis from colorectal cancers identified during postoperative follow-up.

METHODOLOGY

Nine cases of ovarian metastasis were observed among 452 female patients with colon cancers between 1990 and 2000. Initial symptoms were pain (67%), pelvic mass (50%), vaginal bleeding (33%), and uterine bleeding (17%). On pathological evaluation, six cases (67%) were found to be moderately differentiated, and three (33%) well differentiated adenocarcinomas.

RESULTS

Early diagnosis is very difficult. The growth of metastatic ovarian tumors are slow in elder patients, its growth is rapid in younger patients, and frequently diagnosed as huge ovarian tumors. In some cases, as cystic ovarian lesions they were identified in their early stage but could not be diagnosed as ovarian metastases, later curative operation could not be performed. The consulting gynecologist could not reach the correct diagnosis. Regular postoperative pelvic CT or MRI should be helpful for diagnosis. Although serum CEA levels did not increase in most cases, tumor markers CA125 and SLX were elevated in several cases, and thus may be useful for the detection of ovarian metastases. Surgical treatment consisted of bilateral and unilateral salpingo-oophorectomy or pelvic exenteration and additional hysterectomy for one patient because of association with cervical cancer. The median survival time after the primary operation was 20.8 months, ranging from 3 to 96 months. Peritoneal dissemination and bone metastases were frequently observed as recurrence after these operations. Two cases (non-synchronous solitary metastasis or direct involvement, located in the pelvis) survived more than 5 years (85 and 96 months, respectively), and both patients were treated with pelvic exenteration.

CONCLUSIONS

This suggests that in general most cases with ovarian metastasis have a poor prognosis and that radical operation such as pelvic exenteration can improve survival only in cases of recurrent solitary ovarian metastasis or local extended disease, i.e. when the lesion is located only in the pelvis.

Outcome of surgical treatment for patients with scirrhous carcinoma of the stomach

BACKGROUND

Postoperative survival in patients with scirrhous gastric carcinoma is poorer than that in patients with other gastric carcinomas.

METHODS

We retrospectively examined outcome in patients with scirrhous gastric carcinoma who underwent gastrectomy to determine how to increase postoperative survival. Postoperative survival in patients with scirrhous gastric carcinoma was compared with that in patients having other gastric cancers overall and by disease stage. Prognostic factors were examined for all patients including those with stage III disease.

RESULTS

By multivariate analysis, disease stage, patient age, and scirrhous carcinoma were significant prognostic factors. Five-year survival in patients with stage III scirrhous carcinoma was significantly worse than those with other stage III gastric carcinomas. Extent of lymphadenectomy was one of the variables influencing survival in patients with stage III scirrhous carcinoma.

CONCLUSIONS

Gastrectomy with extended lymphadenectomy should be performed to maximize survival in patients with stage III scirrhous gastric carcinoma.

Transanal excision of a large rectal polyp assisted by transsacral manipulation of the rectum

Standard transanal excision of the rectal polyps is curative and is less invasive than transsacral resection or low anterior resction, but it is difficult to resect tumors that are distant from the anal verge. Moreover, in the case of large polyps, the risks of complications, such as hemorrhage or perforation, increase because exposure on the oral side of the tumor is poor. If exposure can be improved, transanal excision can be performed safely and completely when the polyp is large and distant from the anal verge. We used transsacral manual assistance to achieve transanal resection of a large tubulovillous adenoma of the rectum that was hard to be resected using the traditional transanal approach.

Intratumoral administration of methotrexate bound to activated carbon particles: antitumor effectiveness against human colon carcinoma xenografts and acute toxicity in mice

We previously developed a new formulation of methotrexate (MTX) that is adsorbed onto a suspension of activated carbon particles (MTX-CH) and reported the usefulness of local administration in murine tumors. The present study examines the effects of human colon carcinoma (LoVo) xenografts and the acute toxicity of MTX-CH compared with MTX aqueous solution (MTX-AQ) in mice. In therapeutic experiments, LoVo cells were implanted into the backs of BALB/c nude mice. When the cells had developed into tumors, we performed an intratumoral administration of a weekly dose of 30 mg/kg. The MTX concentration in the tumor was compared between the MTX-CH group and MTX-AQ group. In experiments on acute toxicity, MTX-CH and MTX-AQ were injected subcutaneously in BDF1 mice, and intoxication symptoms, changes in body weight, and date of death were recorded. In the therapeutic experiments, intratumoral administration of MTX-CH was much more effective in suppressing the tumor growth compared with MTX-AQ. In experiments of acute toxicity, the death time of the MTX-CH group was delayed to a greater extent, and the 50% lethal dose (LD(50)) values of MTX-CH were lower than those of MTX-AQ. The LD(50) values of MTX-CH are 75 times higher than the efficacious dose of 30 mg/kg. The present results suggest that intratumoral administration of MTX-CH is useful for local therapy and the therapeutic dose of MTX-CH can be safely injected subcutaneously.

Snail and SIP1 increase cancer invasion by upregulating MMP family in hepatocellular carcinoma cells

Loss of E-cadherin (E-cad) triggers invasion, metastasis, and dedifferentiation in various epithelial carcinomas. Recently, it has been reported that two transcription factors, Snail and SIP1 (Smad interacting protein 1), directly repress transcription of the E-cad gene by binding E-box on E-cad promoter. Our aim is to solve the molecular mechanism of Snail and SIP1 in hepatocellular carcinoma (HCC). We first showed an inverse correlation between E-cad and Snail/SIP 1 expression among five HCC lines with different phenotypes. The result indicated that undifferentiated, but not differentiated type expressed Snail/SIP1. Then, we established transfectants stably expressing Snail and SIP1 in two differentiated cells with E-cad expression. Suppressed expression of E-cad, morphologic change into fibroblastoid feature, and remarkable acceleration of invasion activity were observed in the transfectants. In reverse transcription–polymerase chain reaction series of genes relating to motility and invasion, we demonstrated striking evidence that matrix metalloproteinase (MMP-1), MMP-2, MMP-7, and MT1-MMP expressions were strongly upregulated by Snail. On the other hand, MMP-1, MMP-2, and MT1-MMP expressions were enhanced by SIP1 transfection, however, the intensity was weaker than that in Snail transfection. In conclusion, Snail or SIP1 expression may be induced during HCC progression, where Snail/SIP1 directly represses E-cad gene transcription and activates cancer invasion via the upregulation of the MMP gene family.

Dendritic cell-based immunotherapy of cancer with carcinoembryonic antigen-derived, HLA-A24-restricted CTL epitope: Clinical outcomes of 18 patients with metastatic gastrointestinal or lung adenocarcinomas

We conducted a clinical study of cancer vaccine therapy with dendritic cells (DCs) and HLA-A24-restricted carcinoembryonic antigen (CEA)-derived peptide to assess the feasibility and efficacy of such therapy. Eighteen patients with CEA-expressing metastatic gastrointestinal or lung adenocarcinomas who were positive for human leukocyte antigen (HLA)-A24 were enrolled. DCs were generated from the patients' autologous monocyte-enriched fractions of granulocyte colony-stimulating factor-mobilized peripheral blood mononuclear cells in the presence of granulocyte/macrophage colony-stimulating factor and interleukin-4. The generated DCs were pulsed with CEA-derived, HLA-A24-restricted 9-mer peptide (CEA652) and injected into the patients intradermally and subcutaneously every 2 weeks. Toxicity and clinical and immunological responses were closely monitored in each patient. No severe toxicity directly attributable to the treatment was observed, and the vaccine was well tolerated. Although no definite tumor shrinkage occurred in any patient, long-term stable disease or marked decreases in the serum CEA level were observed in some patients after therapy. Most of the patients in whom treatment was clinically effective showed a positive skin response to CEA652-pulsed DCs (delayed-type hypersensitivity skin test) and a positive in vitro CTL response to CEA652 peptide after therapy. We conclude that active specific immunotherapy using DCs pulsed with CEA652 is a safe and feasible treatment that is clinically effective in some patients with metastatic gastrointestinal or lung adenocarcinomas. Our results will hopefully encourage further refinement and development of DC-based immunotherapy with HLA-A24-restricted CEA-derived peptide for refractory solid cancers that express CEA.

Dendritic cell-based immunotherapy of cancer with carcinoembryonic antigen-derived, HLA-A24-restricted CTL epitope: Clinical outcomes of 18 patients with metastatic gastrointestinal or lung adenocarcinomas

We conducted a clinical study of cancer vaccine therapy with dendritic cells (DCs) and HLA-A24-restricted carcinoembryonic antigen (CEA)-derived peptide to assess the feasibility and efficacy of such therapy. Eighteen patients with CEA-expressing metastatic gastrointestinal or lung adenocarcinomas who were positive for human leukocyte antigen (HLA)-A24 were enrolled. DCs were generated from the patients' autologous monocyte-enriched fractions of granulocyte colony-stimulating factor-mobilized peripheral blood mononuclear cells in the presence of granulocyte/macrophage colony-stimulating factor and interleukin-4. The generated DCs were pulsed with CEA-derived, HLA-A24-restricted 9-mer peptide (CEA652) and injected into the patients intradermally and subcutaneously every 2 weeks. Toxicity and clinical and immunological responses were closely monitored in each patient. No severe toxicity directly attributable to the treatment was observed, and the vaccine was well tolerated. Although no definite tumor shrinkage occurred in any patient, long-term stable disease or marked decreases in the serum CEA level were observed in some patients after therapy. Most of the patients in whom treatment was clinically effective showed a positive skin response to CEA652-pulsed DCs (delayed-type hypersensitivity skin test) and a positive in vitro CTL response to CEA652 peptide after therapy. We conclude that active specific immunotherapy using DCs pulsed with CEA652 is a safe and feasible treatment that is clinically effective in some patients with metastatic gastrointestinal or lung adenocarcinomas. Our results will hopefully encourage further refinement and development of DC-based immunotherapy with HLA-A24-restricted CEA-derived peptide for refractory solid cancers that express CEA.

Overexpression of dopa decarboxylase in peritoneal dissemination of gastric cancer and its potential as a novel marker for the detection of peritoneal micrometastases with real-time RT-PCR

We previously performed a global analysis of the gene expression of gastric cancer cell lines established from metastases to the peritoneal cavity with the cDNA microarray method, which made it possible to analyse the expression of approximately 21 168 genes for the identification of novel markers for the detection of micrometastases in the peritoneal cavity. One of the upregulated genes is dopa decarboxylase (DDC), which is responsible for the synthesis of the key neurotransmitters dopamine and serotonine. We have examined its potential as a novel marker for the detection of peritoneal micrometastases of gastric cancer.

DDC mRNA in the peritoneal wash from 112 gastric cancer patients was quantified for comparison of carcinoembryonic antigen (CEA) mRNA by means of real-time reverse transcriptase–polymerase chain reaction (RT–PCR) with a fluorescently labelled probe to predict peritoneal recurrence. The quantity of DDC and CEA correlated with wall penetration. Real-time RT–PCR could quantitate 10–10⁶ DDC-expressing gastric cancer cells per 10⁷ mesothelial cells. The cutoff value was set at the upper limit of the quantitative value for noncancer patients, and those above this cutoff value constituted the micrometastasis (MM+) group. Of 15 cases with peritoneal dissemination, 13 were MM+DDC (87% sensitivity), and one of 48 t1 cases was MM+ (98% specificity). DDC levels in peritoneal washes from patients with synchronous peritoneal metastases were more than 50 times higher than in those from patients without metastasis (P<0.01). For 15 cases of peritoneal dissemination (seven cases were cytologically positive), DDC was positive in 13 cases (87% sensitivity), but CEA failed to detect micrometastases in four cases (73% sensitivity), indicating that DDC is in some cases superior to CEA for the detection of peritoneal micrometastases of gastric cancer in terms of sensitivity as well as specificity, especially for poorly differentiated adenocarcinomas. A combination of CEA and DDC improved the accuracy of diagnosis up to 94%.

These results suggest that DDC is potentially a novel marker for peritoneal dissemination of gastric cancer and that quantitative RT–PCR of DDC is reliable and efficient for the selection of patients for adjuvant intraperitoneal chemotherapy to prevent peritoneal recurrence.

Combination of L-3-phosphoserine phosphatase and CEA using real-time RT-PCR improves accuracy in detection of peritoneal micrometastasis of gastric cancer

Peritoneal metastasis is the most frequent form of recurrence for advanced gastric cancer. We previously performed a global analysis of the gene expression of gastric cancer cell lines established from peritoneal metastasis with cDNA microarray. One of the up-regulated genes is L-3-phosphoserine phosphatase (L3-PP). We have examined its potential as a novel marker for the detection of peritoneal micrometastasis of gastric cancer. L3-PP mRNA in peritoneal wash from 88 gastric cancer patients was quantified for comparison of carcinoembryonic antigen (CEA) mRNA by means of real-time RT-PCR with a fluorescently-labeled probe to predict peritoneal recurrence. The quantity of L3-PP and CEA correlated with wall penetration. The cut-off value was set at the upper limit of the quantitative value of T1 cases (tumor invades within submucosa) and those above the cut-off value constituted the micrometastasis (MM+) group; eight out of 14 cases with peritoneal dissemination were MM+ L3-PP (57.1% sensitivity) and two out of 57 T1 and T2 cases were MM+ (93% specificity). For two out of 14 cases of peritoneal dissemination only L3-PP could detect micrometastasis of gastric cancer, indicating that L3-PP is superior to CEA especially in poorly-differentiated adenocarcinoma. The combination of CEA and L3-PP improved the accuracy of diagnosis up to 85.7%. Consequently, free cancer cells that cannot be detected by CEA mRNA could be detected using L3-PP mRNA. CEA alone was not sufficient, but L3-PP and CEA in combination can attain a higher accuracy of detection.