[Three Cases of Appendiceal Goblet Cell Adenocarcinoma in Our Institution].

Appendiceal goblet cell adenocarcinoma(AGCA)is a newly designated pathological term adopted in the 5th edition of the WHO classification. It is synonymous with goblet cell carcinoid, which was previously categorized as a part of appendiceal carcinoid. However, since 2018, it has been classified as a subtype of adenocarcinoma. We have experienced 3 cases of this relatively rare tumor, of which 2 were initially diagnosed with acute appendicitis and were diagnosed with AGCA by pathological examination after an emergency appendectomy. Each of them underwent additional ileocolic resection with lymph node dissection as the second surgery. In the 3rd case, an appendiceal tumor was detected during preoperative examinations for an ovarian tumor. Staging laparoscopy revealed comorbid peritoneal dissemination, and only the appendix and right ovary were removed in the consecutive surgery. The ovarian tumor was pathologically diagnosed as a metastasis of AGCA. In this case, the introduction of oxaliplatin-based systemic chemotherapy after surgery achieved a complete response after more than 2 years. Although no recurrence has been observed in all 3 cases to date, AGCA is considered highly malignant compared to conventional appendiceal carcinoids. Therefore, it is crucial to practice multidisciplinary treatments, including sufficient radical surgery based on a precise diagnosis of AGCA, as is performed for advanced colorectal cancer.

[Three Cases of Colon Medullary Carcinoma in Our Institution].

Medullary carcinoma of the colorectum is a relatively new histological subtype that was first described in the eighth edition of the Japanese classification of colorectal, appendiceal, and anal carcinoma. In our institution, only 3 cases of medullary carcinoma have been diagnosed since 2013. Case #1 was a 93-year-old woman with type 1 ascending colon cancer; she received a right hemicolectomy. The tumor invaded the subserosal layer, but no lymph nodal metastasis was observed. Case #2 was a 91-year-old woman with obstructive ascending colon cancer. After intracolonic decompression using the transnasal ileus tube, she received a right hemicolectomy. This tumor also extended into the subserosal layer without lymph nodal metastasis. Case #3 was a 65-year-old woman with a family history of cancers; she received a right hemicolectomy for cecal cancer with an aberrant elevation of serum tumor markers such as CEA and CA19-9. The tumor invaded the subserosal layer with regional lymph nodal metastases. Notably, these 3 cases were females who had right-sided tumors and all showed diminished expressions of MLH1 and PMS2 mismatch repair-associated genes, together with epidemiological characteristics of medullary carcinoma. Herein, we report their pathological features along with the corresponding literature review.

Establishment and characterization of novel high mucus-producing lung tumoroids derived from a patient with pulmonary solid adenocarcinoma.

Among mucus-producing lung cancers, invasive mucinous adenocarcinoma of the lung is a rare and unique subtype of pulmonary adenocarcinoma. Notably, mucus production may also be observed in the five subtypes of adenocarcinoma grouped under the higher-level diagnosis of Invasive Non-mucinous Adenocarcinomas (NMA). Overlapping pathologic features in mucus-producing tumors can cause diagnostic confusion with significant clinical consequences. In this study, we established lung tumoroids, PDT-LUAD#99, from a patient with NMA and mucus production. The tumoroids were derived from the malignant pleural effusion of a patient with lung cancer and have been successfully developed for long-term culture (> 11 months). Karyotyping by fluorescence in situ hybridization using an alpha-satellite probe showed that tumoroids harbored aneuploid karyotypes. Subcutaneous inoculation of PDT-LUAD#99 lung tumoroids into immunodeficient mice resulted in tumor formation, suggesting that the tumoroids were derived from cancer. Xenografts from PDT-LUAD#99 lung tumoroids reproduced the solid adenocarcinoma with mucin production that was observed in the patient's metastatic lymph nodes. Immunoblot analysis showed MUC5AC secretion into the culture supernatant of PDT-LUAD#99 lung tumoroids, which in contradistinction was barely detected in the culture supernatants of NCI-A549 and NCI-H2122 pulmonary adenocarcinoma cells known for their mucin-producing abilities. Here, we established a novel high-mucus-producing lung tumoroids from a solid adenocarcinoma. This preclinical model may be useful for elucidating the pathogenesis of mucus-producing lung cancer.

Transforming tumoroids derived from ALK-positive pulmonary adenocarcinoma to squamous cell carcinoma in vivo.

Approximately 3-5% of non-small cell lung cancers (NSCLC) harbor ALK fusion genes and may be responsive to anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitors. There are only a few reports on cell lines with EML4-ALK variant 3 (v3) and tumoroids that can be subject to long-term culture (> 3 months). In this study, we established tumoroids (PDT-LUAD#119) from a patient with lung cancer harboring EML4-ALK that could be cultured for 12 months. Whole-exome sequencing and RNA sequencing analyses revealed TP53 mutations and an EML4-ALK v3 mutation. PDT-LUAD#119 lung tumoroids were sensitive to the ALK tyrosine kinase inhibitors (ALK TKIs) crizotinib, alectinib, entrectinib, and lorlatinib, similar to NCI-H3122 cells harboring EML4-ALK variant 1 (v1). Unexpectedly, clear squamous cell carcinoma and solid adenocarcinoma were observed in xenografts from PDT-LUAD#119 lung tumoroids, indicating adenosquamous carcinoma. Immunostaining revealed that the squamous cell carcinoma was ALK positive, suggesting a squamous transformation of the adenocarcinoma. Besides providing a novel cancer model to support basic research on ALK-positive lung cancer, PDT-LUAD#119 lung tumoroids will help elucidate the pathogenesis of adenosquamous carcinoma.

Patient-derived tumoroid models of pulmonary large-cell neuroendocrine carcinoma: a promising tool for personalized medicine and developing novel therapeutic strategies.

Pulmonary large-cell neuroendocrine carcinoma (LCNEC), a disease with poor prognosis, is classified as pulmonary high-grade neuroendocrine carcinoma, along with small-cell lung cancer. However, given its infrequent occurrence, only a limited number of preclinical models have been established. Here, we established three LCNEC tumoroids for long-term culture. Whole-exome sequencing revealed that these tumoroids inherited genetic mutations from their parental tumors; two were classified as small-cell carcinoma (S-LCNEC) and one as non-small cell carcinoma (N-LCNEC). Xenografts from these tumoroids in immunodeficient mice mimicked the pathology of the parent LCNEC, and one reproduced the mixed-tissue types of combined LCNEC with a component of adenocarcinoma. Drug sensitivity tests using these LCNEC tumoroids enabled the evaluation of therapeutic agent efficacy. Based on translational research, we found that a CDK4/6 inhibitor might be effective for N-LCNEC and that Aurora A kinase inhibitors might be suitable for S-LCNEC or LCNEC with MYC amplification. These results highlight the value of preclinical tumoroid models in understanding the pathogenesis of rare cancers and developing treatments. LCNEC showed a high success rate in tumoroid establishment, indicating its potential application in personalized medicine.

A Study of the Risk Factors for 402 Patients with Esophageal Squamous Cell Carcinoma - A Retrospective Comparison with Health Checkup Participants.

Objective Esophageal cancer is a gastrointestinal cancer with a poor prognosis. However, it is curable and can be treated endoscopically if it is detected at an early stage. The objective of this study was to identify the factors that contribute to early detection. Methods From April 2011 to December 2019, we retrospectively investigated consecutive patients diagnosed with esophageal squamous cell carcinoma (ESCC) through upper gastrointestinal endoscopy at two hospitals of Kawasaki Medical University based on medical records. The factors contributing to the early detection of ESCC were investigated by comparing patients with ESCC with those undergoing health checkups in whom no organic lesions were found in the upper gastrointestinal tract on endoscopy (controls). Patients Factors contributing to early detection were examined in 402 ESCC cases and 391 sex- and age-matched controls, and early and advanced cancers were compared along with the risk factors for ESCC. Results A multivariate analysis showed that alcohol consumption and smoking, concomitant cancer of other organs, and a low body mass index (BMI) were factors associated with ESCC (odds ratio [OR], 4.65; 95% confidence interval [CI], 2.880-7.520, OR,3.63; 95% CI, 2.380-5.540, OR, 2.09; 95% CI, 1.330-3.270, OR, 6.38; 95% CI, 3.780-10.800), whereas dyslipidemia was significantly less common in patients with ESCC (OR, 0.545; 95% CI, 0.348-0.853). Comparing early and advanced cancers, a history of endoscopic screening was the only factor involved in early detection (OR, 7.93; 95% CI, 4.480-14.00). Conclusion The factors associated with ESCC include alcohol consumption, smoking, concomitant cancer of other organs, and a low BMI. Endoscopy in subjects with these factors may therefore be recommended for the early detection of ESCC.

Clinical application of a lung cancer organoid (tumoroid) culture system.

Despite high expectations for lung tumoroids, they have not been applied in the clinic due to the difficulty of their long-term culture. Here, however, using AO (airway organoid) media developed by the Clevers laboratory, we succeeded in generating 3 lung tumoroid lines for long-term culture (>13 months) from 41 lung cancer cases (primary or metastatic). Use of nutlin-3a was key to selecting lung tumoroids that harbor mutant p53 in order to eliminate normal lung epithelial organoids. Next-generation sequencing (NGS) analysis indicated that each lung tumoroid carried BRAFG469A, TPM3-ROS1 or EGFRL858R/RB1E737*, respectively. Targeted therapies using small molecule drugs (trametinib/erlotinib for BRAFG469A, crizotinib/entrectinib for TPM3-ROS1 and ABT-263/YM-155 for EGFRL858R/RB1E737*) significantly suppressed the growth of each lung tumoroid line. AO media was superior to 3 different media developed by other laboratories. Our experience indicates that long-term lung tumoroid culture is feasible, allowing us to identify NGS-based therapeutic targets and determine the responsiveness to corresponding small molecule drugs.

Inhibition of focal adhesion kinase as a potential therapeutic strategy for imatinib-resistant gastrointestinal stromal tumor.

Focal adhesion kinase (FAK) is often up-regulated in a variety of malignancies, including gastrointestinal stromal tumor (GIST), and its overexpression seems to be associated with tumor progressiveness and poor prognosis. GIST is well known to have a mutation to c-KIT; thus, a specific c-KIT inhibitor (imatinib) is recognized as the first-line chemotherapy for GIST, although a certain type of c-KIT mutation reveals a resistance to imatinib due to as yet uncertain molecular mechanisms. To assess the c-KIT mutation-related variation of cellular responses to imatinib, murine lymphocyte-derived Ba/F3 cells, which are stably transduced with different types of c-KIT mutation, were treated with either imatinib or a FAK inhibitor (TAE226), and their antitumor effects were determined in vitro and in vivo. A mutation at exon 11 (KITdel559-560) displayed a high sensitivity to imatinib, whereas that at exon 17 (KIT820Tyr) showed a significant resistance to imatinib in vitro and in vivo. KIT820Tyr cells appeared to maintain the activities of FAK and AKT under the imatinib treatment, suggesting that FAK might play a role in cell survival in imatinib-resistant cells. When FAK activity in those cells was inhibited by TAE226, cell growth was equally suppressed and the cells underwent apoptosis regardless of the c-KIT mutation types. Oral administration of TAE226 significantly diminished tumor growth in nude mice bearing KIT(820Tyr) xenografts. In summary, c-KIT mutation at exon 17 displayed a resistance to imatinib with maintained activations of FAK and subsequent survival signals. Targeting FAK could be a potential therapeutic strategy for imatinib-resistant GISTs.

Resistance to paclitaxel therapy is related with Bcl-2 expression through an estrogen receptor mediated pathway in breast cancer.

Taxanes are approved for the treatment of breast cancer that has spread to the lymph nodes, following surgery and doxorubicin containing chemotherapy. Taxanes have improved the survival of breast cancer patients, especially in estrogen receptor (ER) negative population in clinical settings. This time we examined the relationship between chemosensitivity to Taxanes and expresson of ERalpha in breast cancer cell lines. In vitro effects of paclitaxel in 4 ER-positive and 3 ER-negative breast cancer cell lines were investigated by MTT assay. We also investigated members of Bcl-2 family by Western blotting and RT-PCR to clarify their role in paclitaxel resistance both in ER-positive and in ER-negative cells. ER-negative cell lines were more sensitive to paclitaxel than ER-positive cells. ER-negative KPL-4 and ZR-75-30 cells, which were sensitive to paclitaxel, became resistant when they were treated with demethylation agent, 5-aza-2'-deoxycytidine. Analysis of proapoptotic (Bax) and antiapoptotic (Bcl-2) molecules suggested that Bcl-2 is likely to have a role in the resistance of ER-positive cells. Bcl-2 expression was increased in a time-dependent manner after treatment of ER-positive cell lines with estrogen (E2). On the other hand, Bcl-2 was not detected in ER-negative cell lines. However, no significant difference was detected for Bax mRNA levels before and after E2 treatment in ER-positive and negative cell lines. Activation of ER gene expression in ER-negative KPL-4 cells by 5-aza-2'-deoxycytidine resulted in up-regulation of Bcl-2 mRNA. To support our data, we examined paclitaxel sensitivity in ER-negative MDA-MB-231 and ER stable transfectant cells S30 and JM6. This experiment also showed ER-negative cells were sensitive to paclitaxel but ER-positive cells were resistant to it. These results suggest that ER influenced chemosensitivity to paclitaxel through regulation of Bcl-2 family and regulation of the pathway may be crucial to increase the efficacy of taxanes in ER-positive breast cancer.

Dual tyrosine kinase inhibitor for focal adhesion kinase and insulin-like growth factor-I receptor exhibits anticancer effect in esophageal adenocarcinoma in vitro and in vivo.

PURPOSE: Focal adhesion kinase (FAK) regulates integrin and growth factor-mediated signaling pathways to enhance cell migration, proliferation, and survival, and its up-regulation correlates malignant grade and poor outcome in several types of cancer. In this study, we aimed to raise a potential therapeutic strategy using a FAK inhibitor for Barrett's esophageal adenocarcinoma. EXPERIMENTAL DESIGN: The expression status of FAK in clinical Barrett's esophageal adenocarcinoma tissues was determined by immunohistochemistry. Cultured esophageal adenocarcinoma cells were treated with TAE226, a specific FAK inhibitor with an additional effect of inhibiting insulin-like growth factor-I receptor (IGF-IR), to assess its anticancer effect in vitro. Western blot was carried out to explore a participating signaling pathway for TAE226-induced cell death. Furthermore, TAE226 was orally administered to s.c. xenograft animals to investigate its anticancer effect in vivo. RESULTS: Strong expression of FAK was found in 94.0% of Barrett's esophageal adenocarcinoma compared with 17.9% of Barrett's epithelia, suggesting that FAK might play a critical role in the progression of Barrett's esophageal adenocarcinoma. When esophageal adenocarcinoma cells were treated with TAE226, cell proliferation and migration were greatly inhibited with an apparent structural change of actin fiber and a loss of cell adhesion. The activities of FAK, IGF-IR, and AKT were suppressed by TAE226 and subsequent dephosphorylation of BAD at Ser(136) occurred, resulting in caspase-mediated apoptosis. In vivo tumor volume was significantly reduced by oral administration of TAE226. CONCLUSIONS: These results suggest that TAE226, a dual tyrosine kinase inhibitor for FAK and IGF-IR, could become a new remedy for Barrett's esophageal adenocarcinoma.

[The transition of therapy for recurrent esophageal cancer by PET-CT].

In our institute, we introduced PET-CT examination as the preoperative and postoperative screening for esophageal cancer patients in April 2006. During two years before the introduction of PET-CT examination, we performed an intensive local control therapy (operation, RFA, definitive chemoradiotherapy) to 13 cases with single region recurrence (including 5 cases of cervical lymph nodes recurrence, 5 of local recurrence, 3 of distant metastatic recurrence). On the other hand, we performed an intensive local control therapy to 21 cases (including 4 cases of cervical lymph nodes recurrence, 10 of local recurrence, and 7 of distant metastatic recurrence) during two years after the introduction of PET-CT examination. In any pattern, there was a tendency of improvement in the prognosis of recurrent esophageal cancer patients. These results raised the possibility that PET-CT examination was useful for an early detection of the recurrent lesions in postoperative follow-up for esophageal cancer patients. And there might be a chance of curability in patients with single region recurrence by the early detection.

A case report of left lower lobe segmentectomy for pulmonary metastasis from retroperitoneal liposarcoma.

BACKGROUND: The principle treatment for retroperitoneal liposarcoma is surgical resection, however there are many cases of recurrence. In addition to local recurrence, retroperitoneal liposarcoma, particularly dedifferentiated liposarcoma is known to occasionally cause lung metastases. CASE REPORT: A 72-year-old woman with a diagnosis of retroperitoneal liposarcoma and probable right upper lobe early pulmonary adenocarcinoma underwent sequential local tumor resection and right upper lobectomy. Twenty months after liposarcoma resection, a computed tomography (CT) scan of the chest revealed a nodule located in the left lower lobe. A CT-guided biopsy was performed and she was subsequently diagnosed with pulmonary metastasis from retroperitoneal liposarcoma. The nodule enlarged chronologically, however a left lower lobectomy could not be performed because respiratory function after the right upper lobectomy was not sufficient. Therefore, in order to preserve the left superior segment (S6), the basal segments (S8+S9+S10) were resected. Seven months after the surgery, she is living a self-reliant life without recurrence of liposarcoma. CONCLUSION: Here we have reported a case of pulmonary metastasis from retroperitoneal liposarcoma following limited surgery. In cases where respiratory function is limited, lower lobe segmentectomy can be an effective treatment. For the treatment of a single pulmonary metastasis from retroperitoneal liposarcoma, metastasectomy was considered to be effective as long as no local recurrence was seen after initial primary tumor resection.

[Case with hepatic artery aneurysm discovered after suffering from infectious endocarditis].

A 53-year-old man suffering from infectious endocarditis developed a rupture of the mitral valve tendinous cord. Consequently a mitral valvoplasty was performed. Forty days later, the patient presented with sudden and severe epigastralgia and hematemesis, and was rushed to our hospital. An arterial phase of an abdominal contrast-enhanced CT showed a mass 3 cm in diameter which was strongly enhanced along the side of the hepatic portal region and therefore it was thought to be an aneurysm. An abdominal angiography revealed an aneurysm of the right hepatic artery. As a result, an embolization with coils was performed. Nine months after treatment, CT examination of the abdomen revealed that the aneurysm had completely disappeared.

False-Positive Cases of Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomographic Scans in Metastasis of Esophageal Cancer.

Of 129 esophagectomies at our institute from June 2010 to March 2015, we experienced three preoperative positron emission tomography-computed tomographic (PET/CT) false positives. Bone metastasis was originally suspected in 2 cases, but they were later found to be bone metastasis negative after a preoperative bone biopsy and clinical course observation. The other cases suspected of mediastinal lymph node metastasis were diagnosed as inflammatory lymphadenopathy by a pathological examination of the removed lymph nodes. Conducting a PET/CT is useful when diagnosing esophageal cancer metastasis, but we need to be aware of the possibility of false positives. Therapeutic decisions should be made based on appropriate and accurate diagnoses, with pathological diagnosis actively introduced if necessary.

Targeted silencing of SOX2 by an artificial transcription factor showed antitumor effect in lung and esophageal squamous cell carcinoma.

SOX2 is a transcription factor essential for early mammalian development and for the maintenance of stem cells. Recently, SOX2 was identified as a lineage specific oncogene, recurrently amplified and activated in lung and esophageal squamous cell carcinoma (SCC). In this study, we have developed a zinc finger-based artificial transcription factor (ATF) to selectively suppress SOX2 expression in cancer cells and termed the system ATF/SOX2. We engineered the ATF using six zinc finger arrays designed to target a 19 bp site in the SOX2 distal promoter and a KOX transcriptional repressor domain. A recombinant adenoviral vector Ad-ATF/SOX2 that expresses ATF/SOX2 suppressed SOX2 at the mRNA and protein levels in lung and esophageal SCC cells expressing SOX2. In these kinds of cells, Ad-ATF/SOX2 decreased cell proliferation and colony formation more effectively than the recombinant adenoviral vector Ad-shSOX2, which expresses SOX2 short hairpin RNA (shSOX2). Ad-ATF/SOX2 induced the cell cycle inhibitor CDKN1A more strongly than Ad-shSOX2. Importantly, the ATF did not suppress the cell viability of normal human cells. Moreover, Ad-ATF/SOX2 effectively inhibited tumor growth in a lung SCC xenograft mouse model. These results indicate that ATF/SOX2 would lead to the development of an effective molecular-targeted therapy for lung and esophageal SCC.

SOX2 suppresses CDKN1A to sustain growth of lung squamous cell carcinoma.

Since the SOX2 amplification was identified in lung squamous cell carcinoma (lung SCC), SOX2 transcriptional downstream targets have been actively investigated; however, such targets are often cell line specific. Here, in order to identify highly consensus SOX2 downstream genes in lung SCC cells, we used RNA-seq data from 178 lung SCC specimens (containing tumor and tumor-associated cells) and analyzed the correlation between SOX2 and previously-reported SOX2-controlled genes in lung SCC. In addition, we used another RNA-seq dataset from 105 non-small cell lung cancer cell lines (NSCLC; including 4 lung SCC cell lines) and again analyzed the correlation between SOX2 and the reported SOX2-controlled genes in the NSCLC cell lines (no tumor-associated cells). We combined the two analyses and identified genes commonly correlated with SOX2 in both datasets. Among the 99 genes reported as SOX2 downstream and/or correlated genes, we found 4 negatively-correlated (e.g., CDKN1A) and 11 positively-correlated genes with SOX2. We used biological studies to demonstrate that CDKN1A was suppressed by SOX2 in lung SCC cells. G1 cell cycle arrest induced by SOX2 siRNA was rescued by CDKN1A siRNA. These results indicate that the tumorigenic effect of SOX2 in lung SCC cells is mediated in part by suppression of CDKN1A.

Feasibility of oral administration of S-1 as adjuvant chemotherapy in gastric cancer: 4-week S-1 administration followed by 2-week rest vs. 2-week administration followed by 1-week rest.

In 2006, the Adjuvant Chemotherapy Trial of S-1 for Gastric Cancer (ACTS-GC) demonstrated that S-1 is an effective adjuvant therapy for gastric cancer. Following that study, S-1 has been used as the standard adjuvant therapy for gastric cancer in Japan. However, the 1-year completion rate was only 65.8% in the ACTS-GC study and feasibility remains a critical issue. We conducted a study to evaluate the feasibility of 2 weekly administration regimens of S-1 as adjuvant chemotherapy in gastric cancer. The criteria for eligibility included histologically proven stage II (excluding T1), IIIA or IIIB gastric cancer with D2 lymph-node dissection. The patients were randomly assigned to either arm A (S-1 administration for 4 weeks followed by 2 weeks of rest) or arm B (S-1 administration for 2 weeks followed by 1 week of rest). In each arm, treatment was continued for 12 months unless recurrence or severe adverse events were observed. The primary endpoint was feasibility (protocol treatment completion rate). The secondary endpoints were safety, relapse-free survival and overall survival. A total of 47 patients were assigned to arms A or B between May, 2008 and February, 2010. During the first interim analysis, the protocol treatment completion rates in arms A and B were 83 and 100%, respectively at 6 months and 49 and 89%, respectively, at 12 months (P=0.0046). Therefore, S-1 administration for 2 weeks followed by 1 week rest was more feasible as adjuvant chemotherapy in gastric cancer. Grade 3 adverse events in arm A included fatigue (8.0%), anorexia (8.0%), nausea (4.0%), vomiting (4.0%) and hand-foot syndrome (4.0%), whereas none were observed in arm B. There were no reported grade 4 adverse events in either arm. In conclusion, the 2-week S-1 administration followed by 1-week rest regimen appears to be a more feasible oral administration regimen for S-1 as adjuvant chemotherapy in gastric cancer.

Macrophage colony-stimulating factor inhibits tumor necrosis factor production and prolongs skin graft survival.

BACKGROUND: Despite the availability of a variety of immunosuppressive agents, acute rejection and infection after organ transplantation remain serious problems. METHODS AND RESULTS: We examined the effect of macrophage colony-stimulating factor (M-CSF) on the production of tumor necrosis factor (TNF) in a Bacille de Calmette Guérin-lipopolysaccharide-challenged mouse model. Both serial and repeated injections of M-CSF inhibited TNF production in a dose-dependent manner. Electrophoretic mobility shift assay showed that M-CSF-induced inhibition of TNF production was a result of suppression of nuclear factor-kappaB. High-dose M-CSF significantly prolonged skin graft survival in mice with orthotopic transplantation compared with the control and low-dose M-CSF groups. The combined administration of low-dose M-CSF and cyclosporine also significantly prolonged graft survival compared with the control and low-dose single agent-treated groups. CONCLUSIONS: Our results indicate that M-CSF at a high dose is a potent inhibitor of cytokine production and can potentially be used as an immunosuppressive agent for allograft rejection.

Cyclin A correlates with the sensitivity of human cancer cells to cytotoxic effects of 5-FU.

We investigated the role of cyclin A in the cytotoxic effect of 5-fluorouracil (5-FU) on cancer cell lines. Experiments were performed using gastric cancer chemosensitive NUGC3, and chemoresistant NUGC3/5FU/L established by repeated exposure to 5-FU. 5-FU inhibited cell growth of NUGC3 in a dose-dependent manner. Low concentrations of 5-FU did not inhibit cell growth of NUGC3/5FU/L, while high concentrations slightly inhibited cell growth. Examination of the cell cycle pattern of NUGC3 cells showed accumulation at S-phase at 10 micro M and at G1-S-phase at 100 micro M of 5-FU. Cell cycle pattern of NUGC3/5FU/L cells did not change 5-FU concentrations. 5-FU increased cyclin A mRNA level in NUGC3 cells but not NUGC3/5FU/L cells. In the presence of 100 micro M 5-FU, cyclin A protein level increased 2.6-fold in NUGC3 and 1.47-fold in NUGC3/5FU/L. 5-FU dose-dependently increased the percentage of cyclin A-positive NUGC3 cells, but not NUGC3/5FU/L cells. The percentage of cyclin A-positive cells in other 5-FU sensitive esophageal, colon and gastric cancer cell lines (T.Tn, LOVO, DLD-1, MKN-7), increased in the presence of 1 and 10 micro M 5-FU, while cyclin A-positive cells in 5-FU resitant hepatocellular and colon carcinoma cell lines (HCC50 and C-1), did not increase with the same treatment. Our results indicate that the cytotoxic effects of 5-FU in human cancer cell lines correlate with cyclin A and it may be used as a predictive factor for chemotherapy response.

p53 expression and p21 expression are mutually exclusive in esophageal squamous cell carcinoma.

The accumulation of p53 protein, which is considered to be caused by a p53 gene mutation, is closely associated with poor prognosis in patients with certain types of carcinomas. The progression of esophageal squamous cell carcinoma (ESCC) is also suspected to depend on p53 gene status. We analyzed the relationship between p53 and p21 protein accumulation in ESCC, and simultaneously analyzed the frequency of apoptosis. Formalin-fixed paraffin-embedded sections were taken from 46 patients who underwent esophagectomy for ESCC. These sections were examined by immunostaining with monoclonal antibodies PAb1801 and EA10 to determine p53 and p21 protein accumulation, respectively. We also analyzed the frequency of apoptosis by TdT-mediated dUTP-biotin nick end-labeling (TUNEL). For estimation of the proportion of stained cells, we used computer analysis with NIH image analysis software. p21 protein accumulation showed an almost inverse distribution to that of p53 protein. In areas where both p53 and p21 proteins were accumulated, few apoptotic cells were observed. Particularly in cases of mucosal tumors, p53 protein was prominently accumulated in the lower layer of the tumor, whereas p21 protein accumulation was confined to the upper layer. Our results suggest that progression of esophageal squamous cell carcinoma is controlled by a p53-dependent pathway.