Ulnar Nerve Neuropathy After Surgery for Intraarticular Distal Humerus Fractures: An Analysis of 116 Patients

PURPOSE

To identify the incidence and the factors associated with a postoperative ulnar nerve neuropathy in patients who had undergone open reduction and internal fixation for intraarticular distal humerus fractures.

METHODS

We retrospectively reviewed 116 patients who had undergone surgery between January 2011 and December 2020. Age, sex, BMI, mechanism of injury, open or closed fracture, operation time, tourniquet time, and nerve injury at the final examination were collected from medical charts. We essentially used the paratricipital approach. In cases in which the reduction of intraarticular bone fragments was difficult, olecranon osteotomy was used. Ulnar nerve function was graded according to a modified system of McGowan. We conducted logistic regression analysis to investigate factors of neuropathy using items identified as statistically significant in univariate analysis as explanatory variables.

RESULTS

Thirty-four patients (29.3%) had persistent neuropathy at the final follow-up. In the modified McGowan classification, 28 patients had grade 1 and 6 patients had grade 2 neuropathy. Olecranon osteotomy emerged as a distinct explanatory variable for the prophylaxis of ulnar nerve neuropathy in the multivariate analysis (odds ratio, 0.30; 95% confidence interval, 0.12-0.73). Anterior transposition, however, was not a statistically significant factor (odds ratio, 1.91; 95% confidence interval, 0.81-4.56).

CONCLUSIONS

Olecranon osteotomy was the only independent factor associated with preventing the occurrence of ulnar nerve neuropathy. Ulnar nerve transposition might not be associated with prevention of ulnar nerve neuropathy.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic IV.

A less invasive operative method using a medial cannulated cancellous screw and single plate fixation for the treatment of transcondylar fracture of the humerus in elderly patients in multicenter (TRON group) study

BACKGROUND

Double plate fixation for transcondylar fracture (TCF) tends to be more invasive to the soft tissue, and often carries a higher risk of postoperative complications, including ulnar nerve neuropathy. This study presents the outcomes of TCF of the distal humerus between patients treated with a single plate and cannulated cancellous screw fixation and patients treated with double plate fixation.

METHODS

Between 2011 and 2021, 371 cases involving treatment of distal humeral fracture were recorded in our multicenter (named TRON group) database. Patients of ≥ 65 years of age with TCF treated with opeb n reduction and internal fixation were included. Clinical outcomes were assessed by the Mayo elbow performance score, range of motion, and total elbow arc joint. Complications included fracture-related infection (FRI) and ulnar neuropathy.

RESULTS

There were significant differences in the average operative time (CCS group vs. Plate group: 119.0 min vs. 186.5 min; p < 0.001) and average tourniquet time (CCS group vs. Plate group: 91.5 min vs. 121.0 min; p < 0.001). FRI occurred as a complication in the Plate group (n = 6). The rates of FRI did not differ to a statistically significant extent (CCS group vs. Plate group: 0% vs. 9.2%; p = 0.477). No patients underwent reoperation. The rate of sensory symptoms in the Plate group was higher than that in the CCS group (CCS group: none [n = 25], numbness [n = 1] vs. Plate group: none [n = 57], numbness [n = 15], sensory depression [n = 2]; p = 0.039).

DISCUSSION

Among patients of ≥ 65 years of age with TCF, the clinical outcomes of patients treated with medial CCS and lateral/posterolateral plate did not differ from those of patients who received double plate fixation, and the former treatment was associated with significantly fewer complications, including ulnar nerve palsy. In addition to double plate fixation, this less invasive method of medial CCS and single plate fixation should be considered as a treatment option for TCF in elderly patients.

Clinical comparison of double-plate fixation by the perpendicular plate method versus parallel plate method for distal humeral fracture: a multicenter (TRON group) study

INTRODUCTION

Double-plating methods are popular, with perpendicular and parallel plate methods being widely used surgical method for the rigid fixation of distal humeral fracture (DHF). However, which plate method is better for DHF remains controversial. The aim of this study was to compare patient outcomes including the incidences of complications and reoperation between the two plate methods.

METHODS

We extracted 383 patients with DHF undergoing surgery between 2011 and 2020 from our multicenter database, which is named TRON. We divided the subjects into two groups: perpendicular plating group (Group A) and parallel plating group (Group B). To adjust for baseline differences between the groups, patients were matched for age, sex, olecranon osteotomy, AO type, and type of injury. We assessed the Mayo Elbow Performance Score (MEPS) at 3 and 6 months and the last follow-up month as the clinical outcome. We investigated the incidences of complications and reoperations in both groups.

RESULTS

After matching, each group comprised 50 patients. There was no significant difference between Group A versus Group B in MEPS score at each time point. The incidence of implant removal in Group B was higher than that in Group A (26.5% vs 50%, p = 0.023).

DISCUSSION

Although there were no significant differences in clinical outcomes or complications between the two groups, the incidence of implant removal was higher in Group B than in Group A. In the parallel plate technique, where the plates have to be placed in areas with thin subcutaneous soft tissue, the incidence of implant removal might be high due to the discomfort caused by the implant.

[Advanced thymic carcinoma effectively treated by surgical resection and postoperative radiation therapy: report of a case]

Thymic carcinomas are rare neoplasms, and standard treatment has not yet been established. We reported a case of advanced thymic carcinoma effectively treated by surgical resection and postoperative radiation therapy. A 71-year-old man was pointed out an abnormal shadow on chest X-ray. Chest computed tomography (CT) scan demonstrated an anterior mediastinal tumor. The tumor was diagnosed as carcinoma by CT-guided tumor biopsy and was extirpated completely with combined partial resection of the left lung. Microscopically, the tumor was diagnosed as thymic carcinoma with direct invasion to the left lung. Following postoperative radiation therapy, the patient is doing well without apparent recurrence 5 years after surgery.

[Peripheral small squamous cell carcinoma (9 mm) of the lung with metastasis to mediastinal lymph nodes]

A 61-year-old man was pointed out a small peripheral lung nodule and mediastinal lymph node swelling on the chest computed tomography (CT). At the operation, it was diagnosed squamous cell carcinoma and right upper lobectomy and nodal dissection were done. The tumor was 9 mm in size and diagnosed as well differentiated squamous cell carcinoma with metastasis to mediastinal lymph nodes. Postoperative radiotherapy was done (50 Gy). The patient is doing well without apparent recurrence 33 months after surgery. We reported a case of peripheral small squamous cell carcinoma (9 mm) of the lung with metastasis to mediastinal lymph nodes.

Serum levels of vascular endothelial growth factor and cavity formation in active pulmonary tuberculosis

BACKGROUND

In active pulmonary tuberculosis, certain cytokines have been postulated to be related to cavity formation, although the detailed mechanism of cavity formation is not yet known.

OBJECTIVE

We examined the relationship between cavity formation in pulmonary tuberculosis and vascular endothelial growth factor (VEGF), which functions as an angiogenesis factor.

METHODS

Forty-eight patients with active pulmonary tuberculosis were divided into two groups according to cavity formation as evaluated by chest high-resolution computed tomography. We evaluated serum VEGF levels by enzyme immunoassay.

RESULTS

Group A (with cavities) was comprised of 22 patients and group B (without cavities) was comprised of 26 patients. The serum levels of VEGF were significantly higher in group B (58.733 +/- 21.612 pg/ml) than those in normal individuals (8.739 +/- 3.656 pg/ml) and in group A (13.053 +/- 8.670 pg/ml) (Mann-Whitney U test, p = 0.0149 and p = 0.0481, respectively). Serum levels of interleukin-8 and tumor necrosis factor-alpha were not significantly different between the two groups.

CONCLUSION

These findings suggested that increased serum VEGF levels subdue cavity formation in active pulmonary tuberculosis.

Significant correlation between interleukin 10 expression and vascularization through angiopoietin/TIE2 networks in non-small cell lung cancer

The expression of interleukin 10 (IL-10) is correlated with clinical prognosis in non-small cell lung cancer [NSCLC (H. Hatanaka et al., ANN: ONCOL:, 11: 815--819, 2000)]. However, the effects of IL-10 expression on vascularization in NSCLC are not apparent. We examined the gene expression of IL-10/IL-10 receptor and various angiogenic/angioinhibitory factors in 95 NSCLC samples to determine the correlation between IL-10 production and vascularization. Vascular endothelial growth factor, angiopoietin [Ang (Ang-1 and Ang-2)], thrombospondin, brain-specific angiogenesis inhibitor 1, vascular endothelial growth factor receptors (KDR and flt-1), and Ang receptor (TIE2) gene expression were evaluated by reverse transcription-PCR. The cellular localization of these factors and vascularity in the cancer stroma were examined immunohistochemically. Seventy-eight (82.1%) and 93 (97.9%) of these 95 NSCLCs were positive for IL-10 and IL-10 receptor, respectively. Ang-1, Ang-2, and TIE2 gene expression was seen in 76 (97.4%), 73 (93.6%), and 78 (100%) of 78 IL-10-positive NSCLCs, respectively, and was significantly correlated with IL-10 gene expression (P < 0.0088, <0.0008, and 0.0305, respectively; Fisher's exact method). The localizations of Ang-1, Ang-2, and TIE2 were confirmed within tumor cells immunohistochemically. Vascular number and measurement area were significantly higher in the IL-10-positive NSCLCs (33.500 +/- 9.299/microm(2) and 4.742 +/- 1.287%) as compared with IL-10-negative NSCLCs (10.611 +/- 2.839/microm(2) and 0.718 +/- 0.331%; Mann-Whitney U test, P = 0.0039). The IL-10 expression did not show any significant correlation with the expression of other factors. These results suggested that tumor-produced IL-10 promotes stromal vascularization through expression of Ang-1, Ang-2, and TIE2.

Vascular endothelial growth factor (VEGF) expression in the subacromial bursa is increased in patients with impingement syndrome

Vascular endothelial growth factor (VEGF), which is known to be an angiogenetic factor, plays an important role in the inflammation of synovial tissue. To investigate the relationships between VEGF and clinical symptoms in rotator cuff disease, VEGF expression was examined using RT-PCR and immunohistochemical analysis in 50 patients with this disease (26 with full-thickness cuff tear, 12 with partial-thickness tear, and 12 with subacromial bursitis). VEGF mRNA expression was detected in 40 out of 50 patients by RT-PCR. VEGF mRNA expression was found more frequently in the patients with motion pain (39 out of 41) than in those without motion pain (1 out of 9) with statistical significance (Fisher's test, P < 0.001). Thirty-one out of 33 patients with synovial proliferation showed VEGF mRNA expression, whereas the expression of this transcript was found in 9 out of 17 patients without synovial proliferation. This association with synovial proliferation was also significant (Fisher's test, P = 0.0013). Thirty out of 41 patients with motion pain had synovial proliferation but 3 out of 9 patients without motion pain had synovial proliferation. In all these 30 patients with both motion pain and synovial proliferation, VEGF mRNA expression was detected. This association between motion pain and synovial proliferation was also significant (Fisher's test, P < 0.05). The mean vessel count and area in subacromial bursa expressing VEGF was significantly higher than in those without VEGF (Mann Whitney's U test, P < 0.01). These results suggested that VEGF expression is associated with vascularity, synovial proliferation and shoulder motion pain in the rotator cuff disease.

Interleukin-10 relieves the inhibitory effects of interferon-gamma on normal human lung fibroblasts

Interleukin-10 (IL-10) is an important cytokine that suppresses the production of cytokines and chemokines by immune cells. IL-10 has been suggested to be involved in chronic inflammatory responses including the remodeling process in the lung. We investigated the effects of IL-10 on proliferation, extracellular matrix and cytokine production in normal human lung fibroblasts (NHLF). Human IL-10 (hIL-10) complementary DNA (cDNA) was transfected into NHLF using an adenoviral vector. No significant changes were observed in proliferation, fibronectin or procollagen type I production in the NHLF transfected with hIL-10 cDNA. Interferon (IFN)-gamma significantly inhibited cell proliferation and extracellular matrix production in a dose-dependent manner. Transfection of hIL-10 cDNA significantly relieved the suppressive effects of IFN-gamma in NHLF. Transforming growth factor (TGF)-beta production was not significantly affected by either transfection of hIL-10 cDNA or the addition of IFN-gamma. The relief of the suppressive function of IFN-gamma by IL-10 suggested that IL-10 is indirectly involved in the remodeling process in the lung interstitium.

Ribozyme approach to downregulate vascular endothelial growth factor (VEGF) 189 expression in non-small cell lung cancer (NSCLC)

The aim of this study was to further clarify the role of the cell-associated isoform of vascular endothelial growth factor (VEGF189) on tumour growth and vascularity. Five isoforms of VEGF have been identified with different biological activities. VEGF121, VEGF145, VEGF165, VEGF189, VEGF206 are generated by alternative splicing. We used a hammerhead-type ribozyme (V189Rz) to suppress VEGF189 mRNA. The V189Rz specifically cleaved exon 6 of VEGF189 mRNA, but showed no activity against the VEGF121 or VEGF165 isoforms. The V189Rz was introduced into the human non-small cell lung cancer (NSCLC) cell line (OZ-6/VR). The expression level of VEGF189 mRNA was decreased in the OZ-6/VR cells, while VEGF121 and 165 expression was unaltered. The OZ-6/VR cells xenotransplanted into nude mice showed markedly reduced vascularisation and growth, whereas the cell line did not show any decreased growth under tissue culture conditions. The OZ-6/VR cells (1 x 10(5) cells/mouse) formed no tumours, whereas the parental OZ-6 cells formed large tumours within 8 weeks. The specific suppression of VEGF189 by the ribozyme decreased vascularity and xenotransplantability of the lung cancer cell line. Thus, the cell-associated isoform of VEGF, VEGF189, might have a key role in stromal vascularisation and the growth of NSCLC xenografts in vivo.

Ribozyme-mediated inactivation of mutant K-ras oncogene in a colon cancer cell line

Mutation of c-K-ras oncogene is an important step in progression of colon cancer. We used a hammerhead ribozyme (KrasRz) against mutated K-ras gene transcripts (codon 12, GTT) to inactivate mutant K-ras function in the colon cancer cell line SW480, harbouring a mutant K-ras gene. The beta-actin promoter-driven KrasRz sequence (pHbeta/KrasRz) was introduced into these cells (SW480/KrasRz), and we evaluated its effects on growth of the colon cancer. The gene expression of angiogenesis-related molecules (vascular endothelial growth factor and thrombospondin) was also estimated in SW480/KrasRz. KrasRz specifically and efficiently cleaved the mutant K-ras mRNA but not wild-type mRNA in vitro. SW480/KrasRz showed decreased growth rate under tissue culture conditions (P< 0.01, Dunnett's test). The xenotransplantability of SW480/KrasRz (XeSW480/KrasRz) was significantly decreased in nude mice (P< 0.05, Fisher's exact test). Tumour volume of the xenografts XeSW480/KrasRz was significantly smaller than that of XeSW480/DisKrasRz (P< 0.01, Dunnett's test). Gene expression of VEGF was suppressed in SW480/KrasRz, while TSP1 gene expression was enhanced. The SW480/KrasRz cells showed apoptosis-related features including nuclear condensation and DNA fragmentation. These results suggested that the hammerhead ribozyme-mediated inactivation of the mutated K-ras mRNA induced growth suppression, apoptosis and alteration of angiogenic factor expression.

Clinical implications of interleukin (IL)-10 induced by non-small-cell lung cancer

BACKGROUND

The type 2 cytokine interleukin (IL)-10 has been reported to inhibit the antitumour activity of the regional immunity against various neoplasms. Certain lung cancers produce IL-10, but the clinical significance of IL-10 expression is not well understood.

PATIENTS AND METHODS

We examined IL-10 and IL-10 receptor (IL-10R) mRNA expression in 82 non-small-cell lung cancers (NSCLC) by reverse transcription-polymerase chain reaction (RT-PCR) assay. Immunohistochemistry (IHC) and enzyme immunoassay (EIA) were applied to evaluate the cellular localisation and the serum levels of IL-10.

RESULTS

RT-PCR assay revealed IL-10 mRNA expression in 68 (83%) of 82 NSCLC surgical specimens (40 of 50 adenocarcinomas, 22 of 26 squamous cell carcinomas, 5 of 5 large-cell carcinomas, 1 of 1 adenosquamous-cell carcinoma). RT-PCR assay also revealed IL-10R mRNA expression in 79 cases of NSCLC (96.1%). IL-10 expression was confirmed within tumour cells by IHC. EIA showed no significant serum IL-10 elevation in the 12 NSCLC positive for IL-10 mRNA expression (0-2.99 pg/ml). The NSCLC patients with IL-10 production showed significantly poorer prognosis than those without IL-10 production (P < 0.05, Kaplan Meier, log-rank test).

CONCLUSIONS

These results suggested that the cytoplasmic IL-10 correlated to clinical prognosis, and that IL-10 expression is a prognostic factor for NSCLC.

A case of pulmonary adenocarcinoma with overexpression of multidrug resistance-associated protein and p53 aberration

A 66-year-old female patient underwent left upper lobectomy and dissection of the mediastinal lymph nodes. The pathological diagnosis was well-differentiated papillary adenocarcinoma of the lung with metastasis to the mediastinal lymph nodes, p-T2N2MO, stage IIIA. After the operation, she was treated by chemotherapy including lipophilic anticancer compounds (carboplatin and VP-16). The patient unexpectedly showed long survival for 6 years and 2 months without obvious recurrence or metastasis of the cancer. The anticancer compounds were not effective on the recurrent lesions and then she died due to respiratory failure 8 months after recurrence. The autopsy revealed pleural dissemination and intrapulmonary metastasis. Immunohistochemical analysis showed increased multidrug resistance-associated protein (MRP)-positive tumor cells in the recurrent and metastatic lesions, while few MRP-positive cells were apparent in the primary lesion. The MRP-positive cells were accompanied by p53 nuclear accumulation in the carcinoma. This was a case of pulmonary adenocarcinoma with acquired multidrug resistance caused by MRP overexpression and aberrant p53 after chemotherapy.

Adenovirus-mediated anti-K-ras ribozyme induces apoptosis and growth suppression of human pancreatic carcinoma

Human pancreatic cancer is a lethal malignancy, and the lesions show a very high incidence of point mutations of the K-ras oncogene. These alterations can be used as potential targets for specific ribozyme (Rz)-mediated growth suppression of the cancer cells. We designed an anti-K-ras Rz against mutant K-ras gene transcripts (codon 12, GGT to GTT) and generated a recombinant adenovirus (rAd) to express the Rz (rAd/anti-K-ras Rz). More than 95% of Capan-1 human pancreatic cells were infected with rAd/anti-K-ras Rz when treated with the virus at 200 plaque-forming units/cell. The virus, rAd/anti-K-ras Rz, significantly suppressed mutant K-ras gene expression and inhibited the growth of Capan-1 cells. At 3 days postinfection, we observed maximum growth suppression of the cells, characteristic morphological changes of apoptosis such as nuclear condensation and oligonucleosomal DNA fragmentation, and suppression of bcl-2 oncoprotein. These changes were not found in control virus-infected cells. Our results indicated that the virus rAd/anti-K-ras Rz specifically down-regulated the K-ras/bcl-2 pathway and induced apoptotic changes in Capan-1 pancreatic carcinoma cells. High-efficiency adenovirus-mediated delivery of anti-K-ras Rz could become a significant gene therapy strategy against human pancreatic cancer.

Vascularization is decreased in pulmonary adenocarcinoma expressing brain-specific angiogenesis inhibitor 1 (BAI1)

Brain-specific angiogenesis inhibitor 1 (BAI1) is a novel angioinhibitory factor. We examined BAI1 gene expression in 48 pulmonary adenocarcinoma specimens by RT-PCR. Vascular density (number and measurement area) was immunohistochemically evaluated in tumor specimens using anti-CD34 monoclonal antibody. BAI1 gene expression was detected in 38 of 48 pulmonary adenocarcinomas (79. 2%). Vascular number and measurement area were significantly decreased in the BAI1-positive pulmonary adenocarcinomas (19.3+/-4. 4/microm2 and 1.7+/-0.6%) as compared with those in the BAI1-negative carcinomas (75.5+/-42.7/microm2 and 5.5+/-1.5%) (Mann-Whitney U-test, p=0.0017). These results suggest that BAI1 expression may inhibit stromal vascularization in pulmonary adenocarcinoma.

Expression of angiostatic factors in colorectal cancer

Angiogenesis plays an important role in growth and proliferation of cancer. Various angiogenic and angiostatic factors regulate angiogenesis. We examined expression of genes encoding various angiostatic factors: thrombospondin 1 (TSP1), thrombospondin 2 (TSP2), brain-specific angiogenesis inhibitor 1 (BAI1) and angiopoietin 2 (AGP2) in 62 colorectal cancers and 40 samples of extraneoplastic colon mucosa. The expression of the angiostatic factors TSP2 and AGP2 were significantly increased in the cancerous mucosa as compared to these in extraneoplastic mucosa (o2 test; p<0. 0001, and Fisher's exact test; p<0.0001), while the increase in TSP1 expression was not significant. BAI1 expression was slightly decreased in the cancer tissue. These results suggested that specific types of angiostatic factors might have protective roles against cancer cell proliferation via dormancy due to hyponutrition caused by decreased vascularity.

Xenografts of human solid tumors frequently express cellular-associated isoform of vascular endothelial growth factor (VEGF) 189

Vascular endothelial growth factor (VEGF), a major factor mediating tumor stromal angiogenesis, is expressed as five splice variants encoded by a single gene (VEGF121, VEGF145, VEGF165, VEGF189 and VEGF206). Recently, we demonstrated that the cell-associated isoform, VEGF189, plays important roles in establishment of human colon and esophageal cancer xenografts. We have established 228 xenografts originating from various human solid tumors. In this study, we investigated the expression patterns of VEGF isoforms in those tumor xenografts by RT-PCR. The isoform patterns were VEGF121/VEGF165 in 27 xenografts (11.8%) and VEGF121/VEGF165/VEGF189 in 201 (88.2%). All human solid tumor xenografts expressed VEGF189 more frequently than primary tumors reported previously. These results suggest that VEGF189 contributes to the successful xenotransplantability of various human solid tumors via augmentation of stromal vascularization.

[Trans-sternal bilateral thoracotomy for bilateral metastatic lung tumors]

Trans-sternal bilateral thoracotomy has been performed in 4 patients with bilateral metastatic lung tumors. The primary lesion was rectum in one case and the colon in three cases. Two patients were male and 2 were female. Their ages ranged from 63 to 78 years old. An inframammary incision was made with the patient in the supine position, and the chest was entered via the 4th or 5th intercostal space. This procedure provided excellent exposure of the entire mediastinum. Postoperative pain was comparatively severe in the early postoperative period, but was controlled by administering an epidural block. This procedure allows good exposure of the entire thoracic space through a single operative field. We conclude that trans-sternal bilateral thoracotomy is an excellent approach in the patient with bilateral metastatic lung tumors.

Expression of alpha-smooth muscle actin in small bronchioloalveolar adenocarcinoma of the lung: assessment and comparison with noguchi criteria

The Noguchi criteria are useful in assessing the prognosis of patients with small lung adenocarcinoma. Although there is a significant difference in prognosis between type A or B and type C, it is difficult in some cases to distinguish these types accurately by microscopy. In this study, we used immunohistochemistry to examine alpha-smooth muscle actin (alpha-SMA) produced by active fibroblasts in 25 pulmonary adenocarcinomas less than 2 cm in diameter. Eleven of type C (61%) showed positive staining for alpha-SMA, whereas no positive cases were seen in type A or B. The incidence of cancerous blood vessel and lymphatic invasion were significantly higher in alpha-SMA positive cases than in negative cases, and the positive cases showed poorer prognosis. These findings indicate that immunohistochemical detection of alpha-SMA is useful and essential for histological typing by the Noguchi criteria.

Cell-retained isoforms of vascular endothelial growth factor (VEGF) are correlated with poor prognosis in osteosarcoma

Vascular endothelial growth factor (VEGF) is a major angiogenic factor. Osteosarcoma is characterised by hypervascularity and metastatic potential. We examined VEGF mRNA expression, VEGF isoform pattern and VEGF receptor (flt-1 and KDR) by RT-PCR analysis in 30 osteosarcomas. All 30 osteosarcomas expressed VEGF mRNA. 17 osteosarcomas (57%) expressed flt-1 mRNA, whilst 20 (67%) expressed KDR mRNA. 6/30 (20%) osteosarcomas were positive for VEGF121 only, 8 (27%) for VEGF121 + VEGF165, and 16 (53%) for VEGF121 + VEGF165 + VEGF189. Patients with osteosarcomas with VEGF165 (n = 24) had significantly poorer prognosis in comparison with those without VEGF165 (P = 0.022, Wilcoxon's test). The osteosarcomas with VEGF165 had significantly increased vascularity assessed on sections immunostained for CD34 (P < 0.001, Mann-Whitney U test). Although VEGF165 is a soluble isoform, it is also retained on the cellular surface. These results suggest that cell-retained VEGF isoforms (VEGF165, VEGF189) might be essential for neovascularisation in osteosarcoma, whilst the soluble VEGF121 isoform is not sufficient to stimulate neovascularisation in this type of neoplasm.

Heterozygous ras mutations are preserved in serially passaged human tumor xenografts and established cell lines

We examined c-K-ras gene point mutations in human tumor xenografts and established cell lines as markers of genetic stability. Our previous study demonstrated the stability of c-K-ras gene mutations in human primary neoplasms and their tumor xenografts through serial passages in mice. In this study, we established 27 human cell lines derived from various human tumor xenografts in nude mice. Point mutation of the c-K-ras gene at codon 12 was found in 29.6% (8/27) of the cell lines, as well as in 29.6% (8/27) of the xenografts. The eight ras-mutated cell lines were derived from corresponding tumor xenografts carrying the ras mutation. Heterozygous ras gene mutation was confirmed in seven of the eight ras-mutated cell lines, as well as their corresponding xenografts. The incidence, type and heterozygosity of the c-K-ras gene mutation showed no discrepancies between the original xenografts and the established cell lines. From these findings, we concluded that point mutation of the c-K-ras gene was very stable in human tumor xenografts and established cell lines derived from the xenografts.

Multidrug resistance-associated protein (MRP) expression is correlated with expression of aberrant p53 protein in colorectal cancer

Multidrug resistance-associated protein (MRP) is one of the major factors responsible for non-P-glycoprotein (Pgp)-mediated multidrug resistance of human tumour cells. In this study, we examined MRP and aberrant p53 expression in 54 colorectal cancers (CRC), 35 carcinoma in adenomas (CIA) and 40 adenomatous polyps by immunohistochemical procedures. 38 of 54 (70%) CRCs, 16 of 35 (46%) CIAs and 3 of 40 (8%) adenomatous polyps were MRP positive (chi 2 test, P < 0.0001). 36/54 (67%) CRCs, 10/35 (29%) CIAs and 0/40 adenomatous polyps were p53 positive. 30 of the 36 p53-positive CRCs were also MRP positive and 8/10 CIAs were both p53 and MRP positive. MRP overexpression correlated with aberrant p53 accumulation in CRCs and CIAs (chi 2 test, P < = or 0.01). Coexpression of MRP and p53 in the same cells was confirmed in the CRCs and CIAs by double staining procedures. These results suggested that MRP overexpression is related to aberrant p53 expression in CRC.

Inhibition of liver metastasis of colon cancer by in vivo administration of anti-vascular endothelial growth factor antibody

Cancer metastasis via blood vessels is a complicated process involving a number of stages. Vascularization in the cancer stroma is essential for the metastatic process. Vascular endothelial growth factor (VEGF) is an angiogenic factor, and has important roles in tumor progression or metastasis. In this study, we developed a polycolonal antibody to VEGF and examined whether the anti-VEGF antibody could inhibit the metastasis of human xenografts expressing VEGF in nude mice. The xenograft Col-23-JCK expressing VEGF formed metastatic lesions in the liver and/or pancreas when inoculated via the portal vein (splenic vein) into nude mice. The anti-VEGF polyclonal antibody inhibited metastasis to the liver and/or pancreas (4.75+/- 3.62, anti-VEGF-treated vs. 9.73 +/- 8.24, w/o anti-VEGF treatment; Student's t-test, p=0.035). Vascularity in the metastatic lesions was also decreased by anti-VEGF treatment. These results suggest that anti-VEGF antibody administration may be therapeutically useful for prevention of colon cancer metastasis.

Thrombospondin-2 (TSP2) expression is inversely correlated with vascularity in glioma

Thrombospondins (TSPs) are angiostatic factors in various cancers. However, the significance of TSPs has not been well characterised in glioma. We examined TSP1, TSP2 and vascular endothelial growth factor (VEGF) gene expression by reverse transcription-polymerase chain reaction (RT-PCR) in 37 gliomas. Thirty of the 37 glioma specimens showed VEGF gene expression. Eighteen of the 37 gliomas expressed the TSP1 gene. Seven gliomas lacked TSP2 gene expression, while the other 30 expressed TSP2. The lack of TSP2 gene expression was significantly associated with higher histological grade (Fisher's test, P = 0.0019) and increased vessel counts and density (Student's t-test, P < 0.0001), while there were no correlations between TSP1 and VEGF gene expression and clinicopathological features. These results indicate that the lack of TSP2 gene expression is a potent factor for enhancement of angiogenesis in glioma.

Expression pattern of vascular endothelial growth factor isoform is closely correlated with tumour stage and vascularisation in renal cell carcinoma

Vascular endothelial growth factor (VEGF) has five isoforms (VEGF206, 189, 165, 145 and 121). Increased VEGF expression in renal cell carcinoma (RCC) is associated with angiogenesis, but, it is not apparent which isoform is involved in this effect. We examined the isoform patterns of VEGF by reverse transcription-polymerase chain reaction (RT-PCR) in 47 RCCs. All showed increased VEGF expression as compared with extraneoplastic renal tissue. Four of the 47 RCCs showed VEGF121 alone, 10 showed VEGF121 + 165, and 33 showed the VEGF121 + 165 + 189 pattern. Patients with pathological stage pT3-4 RCC showed the VEGF121 + 165 + 189 isoform pattern at a significantly higher incidence (10/10, 100%) than those with pT0-2 (23/37, 62%) (P < 0.022). The VEGF121 + 165 + 189 isoform pattern was also significantly associated with high vessel counts and density (P = 0.0002, Mann-Whitney U test). These observations suggested that the VEGF189 mRNA isoform is closely associated with angiogenesis and results in the growth of RCC.

Expression of the thrombospondin 1 receptor CD36 is correlated with decreased stromal vascularisation in colon cancer

Vascularisation is determined by the balance between various angiogenic and angio-inhibitory factors in cancer stroma. CD36 is a cell adhesion receptor shown to interact with the ligand thrombospondin 1 (TSP1). It has not been determined whether the interaction of TSP1 and its receptor CD36 is correlated with vascularisation or clinical outcome of malignant tumours in vivo. We studied the correlations between expression of TSP1, CD36 and vascularisation and prognosis in 65 colon cancers. Various levels of TSP1 gene expression were observed in 27 of 65 colon cancers. CD36 expression was detected in 33 of 65 cancers, and was significantly correlated with decreased stromal vascularisation (P<0.001). The colon cancers expressing CD36 showed better prognosis (P<0.01). TSP1 expression levels did not affect CD36 expression. These results suggested that CD36 expression which decreased stromal vascularisation is correlated with better prognosis of colon cancer.

Thrombospondin 2 expression is correlated with inhibition of angiogenesis and metastasis of colon cancer

Two subtypes of thrombospondin (TSP-1 and TSP-2) have inhibitory roles in angiogenesis in vitro, although the biological significance of these TSP isoforms has not been determined in vivo. We examined TSP-1 and TSP-2 gene expression by reverse transcription polymerase chain reaction (RT-PCR) analysis in 61 colon cancers. Thirty-eight of these 61 colon cancers were positive for TSP-2 expression and showed hepatic metastasis at a significantly lower incidence than those without TSP-2 expression (P = 0.02). TSP-2 expression was significantly associated with M0 stage in these colon cancers (P = 0.03), whereas TSP-1 expression showed no apparent correlation with these factors. The colon cancer patients with TSP-2 expression showed a significantly low frequency of liver metastasis correlated with the cell-associated isoform of vascular endothelial growth factor (VEGF-189) (P = 0.0006). Vascularity was estimated by CD34 staining, and TSP-2(-)/VEGF-189(+) colon cancers showed significantly increased vessel counts and density in the stroma (P < 0.0001). TSP-2(-)/VEGF-189(+) colon cancer patients also showed significantly poorer prognosis compared with those with TSP-2(+)/VEGF-189(-) (P = 0.0014). These results suggest that colon cancer metastasis is critically determined by angiogenesis resulting from the balance between the angioinhibitory factor TSP-2 and angiogenic factor VEGF-189.

Hammerhead ribozyme specifically inhibits mutant K-ras mRNA of human pancreatic cancer cells

We have evaluated the efficacy of an anti-K-ras hammerhead ribozyme targeted against GUU-mutated codon 12 of the K-ras gene in a cell-free system as well as in cultured pancreatic carcinoma cell lines. In the cell-free system, the anti-K-ras ribozyme specifically cleaved K-ras RNA with GUU-mutation at codon 12, but not other triplet sequences at codon 12 of K-ras RNA. In the cell culture system, the anti-K-ras ribozyme significantly reduced K-ras mRNA level (GUU-mutated codon 12) in Capan-1 pancreatic carcinoma cells, but less significantly suppressed K-ras mRNA in Capan-2 (GUU/GGU heterozygous-mutation at codon 12) or MIA PaCa-2 (UGU-mutated codon 12) pancreatic carcinoma cells. The ribozyme inhibited proliferation of transfected Capan-1 cells. These results suggest that this ribozyme selectively recognizes single-base mutation of K-ras mRNA and is able to reverse the malignant phenotype in human pancreatic carcinoma cells.

Multidrug resistance-associated protein and mutant p53 protein expression in non-small cell lung cancer

Multidrug resistance-associated protein (MRP) is one of the major factors for non-P-glycoprotein (PGp)-mediated multidrug resistance. We reported previously that overexpression of the MRP gene was related to the prognosis of non-small cell lung cancer (NSCLC). It is unclear how MRP expression is regulated in NSCLC. In this study, we examined MRP and mutant p53 expression in 107 NSCLCs by immunohistochemical procedures. Forty-seven (43.9%) of these 107 NSCLCs were positive for MRP in the cytoplasm. Mutant p53-positive NSCLC showed a significant correlation with MRP overexpression (P=.011). Coexpression of MRP and p53 in the same cells of NSCLC was confirmed by double-staining procedures. Twenty-six patients with MRP-positive tumors who underwent postoperative chemotherapy with MRP-related anticancer drugs (vindesine and etoposide) had significantly poorer prognoses than did those with MRP-negative tumors (P=.017). This correlation between MRP expression and prognosis was also seen in Stage III patients (P=.022) and in patients with squamous cell carcinoma (P=.062). NSCLC patients with coexpression of MRP and p53 showed poorer prognoses than did those without MRP and p53 (P=.014). These results suggested that MRP overexpression affected by mutant p53 had a significant effect on prognosis through atypical non-PGp-mediated multidrug resistance in NSCLC.

Alterations in tumour suppressor gene p53 correlate with inhibition of thrombospondin-1 gene expression in colon cancer cells

If activation of the p53 gene is involved in the progression or metastasis of colon cancer, it may affect the angiogenic phenotype in vivo. To verify this hypothesis, we studied the correlation between p53 accumulation and expression of thrombospondin-1 (TSP1) in colon cancer specimens. Levels of TSP1 gene expression were estimated by Northern blotting in 65 colon cancers. Accumulation of p53 and the distribution of TSP1 protein were evaluated immunohistochemically. Various levels of TSP1 gene expression were seen in colon cancers, while p53 accumulation was confirmed in 42 of the 65 colon cancers. The level of TSP1 gene expression demonstrated a significant inverse correlation with p53 accumulation in colon cancer. Colon cancer cells expressed TSP1 protein and p53 accumulation reciprocally in the same nests. These results suggest that alterations in the tumour suppressor gene p53 may inhibit TSP1 expression in colon cancer.

Growth stimulation of non-small cell lung cancer xenografts by granulocyte-macrophage colony-stimulating factor (GM-CSF)

Granulocyte-macrophage colony-stimulating factor (GM-CSF) has been suggested to be involved in the carcinogenesis of some types of tumours by autocrine or paracrine mechanisms. We examined GM-CSF/GM-CSF receptor (GM-CSFR) gene expression in 20 human non-small cell lung cancer (NSCLC) xenografts. The stimulatory effects of GM-CSF were examined using GM-CSF transgenic severe combined immunodeficient (SCID) mice (GM-Tg-SCID), which produce abundant human GM-CSF. A NSCLC xenograft (LC11-JCK), expressed GM-CSFR but not GM-CSF, and showed more rapid growth in GM-Tg-SCID than non-GM-CSF transgenic SCID mice (non-Tg-SCID). GM-CSF gene expression was detected in 48 of 90 (53%) primary NSCLC human specimens and GM-CSFR gene expression was detected in 42 specimens (47%). GM-CSF expression was detected in 13 of 30 squamous cell carcinoma specimens (43%) and GM-CSFR expression was detected in 10 specimens (33%). Patients with squamous cell carcinoma coexpressing GM-CSF and GM-CSFR showed significantly poorer prognosis than those expressing neither GM-CSF nor GM-CSFR (P < 0.05, Cox-Mantel test). These results suggest that GM-CSF can have a stimulatory effect on some NSCLC.

Establishment of an adrenocortical carcinoma xenograft with normotensive hyperaldosteronism in vivo

We established a xenograft line of human adrenocortical carcinoma (ADR-1), and analyzed the hyperaldosteronism induced by the xenograft in vivo. Adrenocortical carcinoma specimens from a 25-year-old woman were subcutaneously inoculated into nude mice (BALB/c-nu/nu) followed by serial passages in vivo. ADR-1 retained the histopathological features (trabecular and sinusoid nests) seen in the primary carcinoma. The patient showed hyperaldosteronism (serum aldosterone >4000 pg/ml) and hypokalemia (serum K 2.1 mEq/l), but did not show hypertension. The nude rat (F344-rnu/rnu) bearing ADR-1 showed hyperaldosteronism (serum aldosterone 3320+/-1420 pg/ml; control 191+/-130 pg/ml) and hypokalemia (serum K 3.4+/-0.4 mEq/l; control 5.2+/-1.0 mEq/l) in vivo, and hypertension was not obvious. ADR-1 was shown immunohistochemically to retain production of human-specific corticosteroid synthetase. The xenograft ADR-1 will be useful to elucidate the regulatory mechanism of normotensive hyperaldosteronism.

Brain-specific angiogenesis inhibitor 1 expression is inversely correlated with vascularity and distant metastasis of colorectal cancer

Brain-specific angiogenesis inhibitor (BAI) 1 was recently isolated as a novel p53 inducible gene. BAI1 has been suggested to play a significant role in angiostasis. We studied the expression of BAI1 in 49 colorectal cancer specimens by RT-PCR. BAI1 expression was significantly reduced in colorectal cancers as compared to the extraneoplastic tissues (X(2) test, p=0.041). BAI1 expression was inversely correlated with vascular invasion and metastasis (Fisher's exact test, p 0.045). Moreover, vascularity in the colorectal cancer was inversely correlated with BAI1 gene expression (Mann-Whitney U-test, p=0.0003). These observations suggested that BAI1 expression might inhibit angiogenesis and metastasis of colorectal cancer.

Increased expression of human histocompatibility leukocyte antigen-G in colorectal cancer cells

Human histocompatibility leukocyte antigen (HLA)-G is a nonclassical major histocompatibility complex class I molecule. HLA-G is known to provide tolerance from recognition by natural killer cells. We studied HLA-G expression in 39 human colorectal cancers and 23 extra-neoplastic colon tissue samples by RT-PCR. The expression of HLA-G mRNA was significantly more frequent in colorectal cancer (34 of 39 cases) than in the extraneoplastic tissue (10 of 23 specimens; chi2 test, p = 0.0003). HLA-G expression was also confirmed on the cancer cells immunohistochemically. These results suggested that HLA-G on colorectal cancer cells may be correlated with escape from immunological surveillance during colon cancer development.

Aberrant isoform of vascular endothelial growth factor 189 expression is correlated with xenotransplantability of human esophageal cancer

Xenografted neoplastic tissues are often utilized to study biology of human cancer. We studied isoform pattern (VEGF206, VEGF189, VEGF165, VEGF121) of an angiogenic factor VEGF in both esophageal primary cancers and cancer xenografts by RT-PCR analysis. Eighteen of 19 (95%) xenografts showed the cell associated aberrant isoform of VEGF189 at a significantly higher incidence than 19 of 31 (61%) primary cancers (P=0.009, Fisher's exact test). These observations suggested that the aberrant isoform of VEGF189 mRNA affects the xenotransplantability of human esophageal cancer.

Thrombospondin 2 gene expression is correlated with decreased vascularity in non-small cell lung cancer

Stromal vascularity is thought to be a major factor involved in the progression of carcinoma. However, the crucial mechanisms of vascularization in the stroma are not well understood. Vascularity could be regulated by various cytokines produced by neoplastic or stromal cells in carcinoma. Thrombospondin (TSP) has an inhibitory role against vascularization in vitro, although the biological significance of TSP has not been characterized in vivo. We examined expression of TSP1 and TSP2 genes in 78 non-small cell lung cancers (NSCLCs) and 33 extraneoplastic lung tissue samples by reverse transcription-PCR. TSP1 expression was detected in 66.7% (52 of 78) of NSCLCs and in 69.7% (23 of 33) of extraneoplastic lung tissue specimens. TSP2 expression was seen in 48.7% (38 of 78) of NSCLCs, whereas 72.7% (24 of 33) of extraneoplastic lung tissue samples showed TSP2 gene expression. TSP2 expression was significantly decreased in NSCLC as compared with extraneoplastic lung tissue (chi2 test, P=0.019). Vascularity in the NSCLC was inversely correlated with TSP2 gene expression (Mann-Whitney U test, P=0.009). Patients with adenocarcinoma positive for TSP2 gene expression (22 of 49) showed significantly better prognosis than those without TSP2 (27 of 49; Cox-Mantel test, P=0.034). TSP1 expression showed no apparent correlation with these factors. These results suggested that TSP2 had an inhibitory role against vascularization and progression of NSCLC.

Hammerhead ribozymes against gamma-glutamylcysteine synthetase mRNA down-regulate intracellular glutathione concentration of mouse islet cells

gamma-Glutamylcysteine synthetase (gamma-GCS) is a key enzyme in glutathione synthesis and is thought to play a significant role in intracellular detoxification systems. To specifically suppress gamma-GCS gene expression, we constructed two different hammerhead ribozymes against gamma-GCS mRNA transcripts. Two cleavage sites were targeted as follows: site 1 for anti-gamma-GCS ribozyme (H), a GUU triplet located from +348 to +350 of the gamma-GCS heavy chain, and site 2 for anti-gamma-GCS ribozyme (L), a GUU triplet located from +235 to +237 of the gamma-GCS light chain. The anti-gamma-GCS ribozymes effectively cleaved gamma-GCS mRNA in a cell-free system. When transfected into a Min-6 mouse islet cell line, these anti-gamma-GCS ribozymes not only suppressed gamma-GCS gene expression, but also reduced intracellular glutathione concentration. These results suggest that the ribozyme-mediated down-regulation of gamma-GCS gene expression may be useful for analyzing the glutathione-associated cellular defense systems of pancreatic islet cells.

Inhibition of tumor growth by ribozyme-mediated suppression of aberrant epidermal growth factor receptor gene expression

BACKGROUND

Amplification and rearrangement of the epidermal growth factor receptor (EGFR) gene is frequently associated with malignant gliomas. One type of EGFR mutation in primary gliomas results in overexpression of an aberrant EGFR messenger RNA (mRNA) that lacks sequences of exons II through VI of the human EGFR gene. We observed that the aberrantly spliced EGFR mRNA contains a ribozyme cleavable sequence (5'-AAG GUA AUU-3') created by the joining of EGFR exon I to exon VII. We hypothesized that an appropriately designed ribozyme RNA could mediate site-specific cleavage of the aberrant EGFR mRNA and reduce the growth of aberrant EGFR-producing tumor cells.

METHODS

We synthesized aberrant EGFR mRNA substrates and a sequence-specific hammerhead ribozyme (abEGFR-rib) to examine the ribozyme's activity in vitro. We also constructed an abEGFR-rib plasmid and introduced it into ERM5-1 cells, which are murine NIH3T3 cells transfected to express an aberrant EGFR complementary DNA. We measured the growth potential of the cotransfected cells in culture and in nude mice.

RESULTS

The synthesized abEGFR-rib efficiently and specifically cleaved aberrant EGFR mRNA substrates in vitro. Expression of the transfected abEGFR-rib suppressed expression of aberrant EGFR mRNA in ERM5-1 cells and reduced the growth of tumors formed by the cotransfected cells in nude mice. Finally, the incorporation of bromodeoxyuridine, a measure of mitotic activity, was also decreased in abEGFR-rib-producing ERM5-1 cells in vivo.

CONCLUSION

Ribozymes targeted to aberrant EGFR mRNA can inhibit the growth of tumors formed by cells that express this mRNA.

A human lung cancer xenograft producing granulocyte-colony stimulating factor and parathyroid hormone-related protein

A human lung cancer xenograft, LC-GP, producing granulocyte-colony stimulating factor and parathyroid hormone-related protein was established by transplantation into severe combined immunodeficient (SCID) mice. The lung cancer patient and SCID mice bearing LC-GP showed leukocytosis and hypercalcemia. G-CSF and PTHrP gene expression were demonstrated in the primary lung cancer, metastatic lesions and LC-GP xenograft. Immunohistochemical analysis confirmed the presence of G-CSF protein in LC-GP xenograft cells. LC-GP possessed activated c-Ki-ras oncogene (point mutation at codon 12). This LC-GP lacked apparent G-CSF receptor expression. The expression of G-CSF and PTHrP may be coregulated by the activated c-Ki-ras oncogene, and autocrine stimulation of G-CSF is unlikely.

Expression of cell-associated isoform of vascular endothelial growth factor 189 and its prognostic relevance in non-small cell lung cancer

Vascular endothelial growth factor (VEGF) has four isoforms (VEGF121, VEGF165, VEGF189, VEGF206). We examined the expression patterns of VEGF isoforms in non-small cell lung cancer (NSCLC) by RT-PCR. The cell-associated isoform VEGF189 was more frequently expressed in NSCLC (90.5%) than in extraneoplastic lung tissue (57.6%, p=0.00004). Immunohistochemical examination confirmed VEGF protein expression in 33 of 76 NSCLC expressing VEGF189 (V189p+ group). The V189p+ group showed significantly poorer prognosis than those without VEGF189 mRNA and protein (V189p- group, p=0.01722). These results suggest that expression of the cell-associated isoform VEGF189 is closely associated with progression of NSCLC.

Vascular endothelial growth factor (VEGF) mRNA isoform expression pattern is correlated with liver metastasis and poor prognosis in colon cancer

Vascular endothelial growth factor (VEGF) is a well known factor that induces angiogenesis. Four isoforms, i.e. VEGF206, 189, 165, and 121, have been identified. We examined the isoform patterns of VEGF mRNA using reverse transcription polymerase chain reaction (RT-PCR) analysis in 61 colon cancers. All the colon cancers examined expressed VEGF121. The isoform patterns were classified into three groups: type 1, VEGF121; type 2, VEGF121 + VEGF165; type 3, VEGF121 + VEGF165 + VEGF189. Three of the 61 colon cancers examined showed type 1 expression, 26 showed type 2 expression and 32 showed the type 3 pattern. The patients with liver metastases showed the type 3 isoform expression pattern at a significantly higher incidence (12 of 16, 75%) than those without liver metastasis (20 of 45, 44%) (P=0.036). The type 3 isoform pattern was significantly associated with M1 stage (P=0.019). The patients with colon cancer and the type 3 isoform pattern showed significantly poor prognosis (P < 0.01, Cox-Mantel). The colon cancers with the type 3 pattern showed a significantly higher involvement of veins (P=0.006). These observations suggest that the aberrant type 3 expression pattern of VEGF189 mRNA isoforms is correlated with liver metastasis, M stage, and poor prognosis in colon cancer.

Multidrug resistance mediated by overexpression of P-glycoprotein in human osteosarcoma in vivo

We examined the expression levels of P-glycoprotein (P-Gp)/the human multidrug resistance gene (MDR1) and in vivo chemosensitivity in the 7 osteosarcoma xenografts. Three of seven (43%) osteosarcoma xenografts expressed MDR1 by reverse transcriptase-polymerase chain reaction (RT-PCR). The OSS-516R xenograft selected with vincristine (VCR) from the MDR1-negative xenograft OSS-516, which was sensitive to VCR and doxorubicin (DOX), acquired cross-resistance to DOX. In the OSS-516R, RT-PCR assay showed definite MDR1 expression and immunohistochemical analysis demonstrated P-Gp-positive tumor cells. These results suggest that P-Gp/MDR1 overexpression is related to multidrug resistance in human osteosarcoma in vivo.

A xenograft line of human teratocarcinoma established by serial transplantation in severe combined immunodeficient (SCID) mice

We established a xenograft line of human teratocarcinoma (TC-1) and characterized the pluripotency of differentiation of the neoplastic cells. A teratocarcinoma specimen obtained from a primary mediastinal lesion (22-year-old male patient) was inoculated subcutaneously into severe combined immunodeficient (SCID) mice. The carcinoma formed tumors in the mice. We established a xenograft line by serial passage of the tumor in vivo. The primary tumor was composed of papillary and pseudoglandular nests of highly atypical epithelial cells with foci of glomeruloid structures. The metastatic cells showed apparent production of mucin and differentiation to striated muscle. The xenograft line TC-1 retained the basic histopathological features seen in the primary and metastatic cells. The xenograft line showed focal differentiation to cartilage through serial passages. Immunohistochemical studies with anti-alpha-fetoprotein (AFP) demonstrated positive immunoreactivity on the TC-1 cells. Serum AFP levels were also elevated in the TC-1-bearing SCID mice. The human teratocarcinoma xenograft line TC-1 will be useful for studying the differentiation mechanism in human totipotent stem cells.

Gene expression of granulocyte colony stimulating factor (G-CSF) in non-small cell lung cancer

Autonomous or continuous granulocyte colony-stimulating factor. (G-CSF)-production in malignant neoplasms is considered to induce leukocytosis without apparent infection. We examined G-CSF gene expression in human non-small cell lung cancer (NSCLC) and discussed its clinicopathological significance. Northern blot analysis revealed G-CSF gene expression in 14 of 84 surgical specimens (16.7%, 10/30 squamous cell carcinoma, 3/50 adenocarcinoma, 1/4 large cell carcinoma). Eight patients (57.1%, 8/14) with NSCLC showing G-CSF gene-expression had peripheral blood leukocytosis (> 8,000/microliter). The prognosis was significantly worse in 10 stage I or II NSCLC showing G-CSF gene expression (p < 0.01, Cox-Mantel test). These findings suggest that G-CSF gene expression is common event in the early stage of primary NSCLC, while it cannot completely explain the leukocytosis induced by lung cancer.

Murine P-glycoprotein on stromal vessels mediates multidrug resistance in intracerebral human glioma xenografts

Human glioma usually shows intrinsic multidrug resistance because of the blood-brain barrier (BBB), in which membrane-associated P-glycoprotein (P-gp), encoded by the human multidrug resistance gene MDR1, plays a role. We studied drug sensitivity to vincristine (VCR), doxorubicin (DOX) and nimustine (ACNU) in both intracerebrally and subcutaneously xenotransplanted human glioma. We examined the levels of MDR1 and murine mdr3 gene expression in the xenografts by reverse transcriptase polymerase chain reaction and the localization of P-gp by immunohistochemistry. Six of seven subcutaneously transplanted xenografts (scX) were sensitive to the above three drugs. In contrast, all three intracerebrally transplanted human glioma xenografts (icX) were resistant to P-gp-mediated drugs VCR and DOX, but were sensitive to the non-P-gp-mediated drug ACNU. Neither icX nor scX showed any MDR1 expression. Intracerebrally transplanted human glioma xenografts showed an increased level of murine mdr3 gene expression, whereas scX showed only faint expression. The localization of P-gp was limited to the stromal vessels in icX by immunohistochemistry, whereas scX expressed no P-gp. Our findings suggest that the P-gp expressed on the stromal vessels in icX is a major contributing factor to multidrug resistance in human glioma in vivo.