Overexpression and activation of hepatocyte growth factor/scatter factor in human non-small-cell lung carcinomas.

Hepatocyte growth factor/scatter factor (HGF/SF) stimulates the invasive growth of epithelial cells via the c-MET oncogene-encoded receptor. In normal lung, both the receptor and the ligand are detected, and the latter is known to be a mitogenic and a motogenic factor for both cultured bronchial epithelial cells and non-small-cell carcinoma lines. Here, ligand and receptor expression was examined in 42 samples of primary human non-small-cell lung carcinoma of different histotype. Each carcinoma sample was compared with adjacent normal lung tissue. The Met/HGF receptor was found to be 2 to 10-fold increased in 25% of carcinoma samples (P = 0.0113). The ligand, HGF/SF, was found to be 10 to 100-fold overexpressed in carcinoma samples (P < 0.0001). Notably, while HGF/SF was occasionally detectable and found exclusively as a single-chain inactive precursor in normal tissues, it was constantly in the biologically-active heterodimeric form in carcinomas. Immunohistochemical staining showed homogeneous expression of both the receptor and the ligand in carcinoma samples, whereas staining was barely detectable in their normal counterparts. These data show that HGF/SF is overexpressed and consistently activated in non-small-cell lung carcinomas and may contribute to the invasive growth of lung cancer.     

Expression of mage genes by non-small-cell lung carcinomas

Human gene MAGE-1 codes for an antigen that is recognized on melanoma cells by autologous cytolytic T lymphocytes (CTL). This antigen is potentially useful as a target for cancer immunotherapy because gene MAGE-1 is not expressed in any normal tissues except the testis. We tested 46 surgical samples of non-small-cell lung carcinomas and observed MAGE-1 expression in 16 of them (35%). Genes MAGE-2 and 3, which are closely related to MAGE-1, were expressed by a similar proportion of these tumors. Some small-cell lung tumors also express MAGE genes. The proportion of tumors expressing MAGE-1 suggests that lung tumor patients may constitute the largest group of patients potentially eligible for pilot studies involving MAGE-1 immunization.     

非小细胞肺癌的新标记物DMP1

Dmp1(Cyclin D binding myb-like protein 1,Dmtf1)是由Ras-Raf信号介导活化,促使依赖Arf和p53的细胞周期停滞的特殊的肿瘤抑制因子。Mallakin等[1]研究发现DMP1缺失可损害Arf/p53对细胞周期调控的抑制作用,从而促进     

Allele-specific detection of K-ras oncogene expression in human non-small-cell lung carcinomas

Point mutations in codon 12 of the K-ras oncogene are frequent in human lung adenocarcinomas. To study the expression of the K-ras gene in these tumors we have developed a mRNA detection technique based on the polymerase chain reaction (PCR). By this technique, K-ras expression can be detected semi-quantitatively in samples of less than 100 ng total RNA. Hybridization of the amplified cDNA sequences with mutation-specific oligonucleotides allows separate quantification of the expression of normal and point-mutated alleles in a single sample. RNA samples from 24 human non-small-cell lung carcinomas (NSCLC), from 2 lung metastases of colonic adenocarcinomas, from 3 human lung adenocarcinoma cell lines, and from normal lung tissue were analyzed. In most tumors, expression of K-ras was detected at levels equal to or several times higher than those found in normal lung tissue. A lung metastasis from a colon adenocarcinoma, known to contain an amplified K-ras gene, highly over-expressed the K-ras gene. In those tumors in which the K-ras oncogene was activated by a point mutation, both alleles of the gene were expressed. Our results show that a high over-expression of K-ras is a rare event in human lung carcinomas, but that a certain degree of over-expression of the mutated allele can be demonstrated in tumors with an activated K-ras gene. With the technique we describe here, adequate estimation of the expression of specific genes in minimal amounts of tumor cells becomes possible.     

Expression of the c-Kit receptor and its ligand SCF in non-small-cell lung carcinomas

Increasing experimental evidence indicates that stem-cell factor (SCF) and its cognate receptor c-Kit may participate in the growth control of various solid human malignancies. In the present study, we have extended this analysis to non-small-cell lung carcinomas (NSCLC). The results of an immunohistochemical analysis demonstrated that c-Kit/SCF are expressed by 30%/58% of adenocarcinomas, 15%/37% of squamous-cell carcinomas and by 40%/30% of undifferentiated carcinomas respectively. In 15% of primary and 18% of metastatic tumors, co-expression of the receptor and its ligand was documented. Western-blot assays of tumor extracts demonstrated that both molecules exhibit features of the normal receptor and ligand. Since biologically active SCF is physiologically present in the bloodstream, our data indicate that SCF is available to c-kit-expressing NSCLC cells via autocrine, paracrine or endocrine mechanisms. Thus activation of c-Kit in these tumors may contribute critically to their progression. Int. J. Cancer 75:171–175, 1998. © 1998 Wiley-Liss, Inc.     

Fibroblast growth factor signaling in non-small-cell lung cancer

Despite recent progress in the treatment on non-small cell lung cancer (NSCLC), outcomes remain suboptimal. Treatment advances that target the epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF) signaling pathways highlight the need to understand the multiple convergent growth factor signaling pathways involved in the pathogenesis of NSCLC. Signaling through fibroblast growth factors (FGF), long recognized for its pro-angiogenic activity, has recently emerged as a contributing factor in the pathogenesis and progression of NSCLC through an autocrine signaling loop. In addition, this pathway may function as a mechanism of resistance to anti-EGFR and anti-VEGF treatment. Clinical experience with FGF receptor (FGFR) inhibitors is mounting, and more specific inhibitors of this signaling pathway are in development. This review describes the structure of the FGF signaling pathway, delineates its dual roles in angiogenesis and proliferation in NSCLC, evaluates FGF ligand and receptor expression as prognostic biomarkers in NSCLC, and discusses the development of FGF pathway inhibitors for the treatment of lung malignancies.     

Epidermal growth factor vaccine in non-small-cell lung cancer

After many years of uncertainty regarding the role of immunotherapy in cancer, we finally have vaccines approved for the treatment of some malignancies (e.g., prostate cancer and melanoma). In non-small-cell lung cancer, several vaccines are being studied in randomized Phase III clinical trials due to their promising results seen in the clinic, such as BLP-25 and melanoma-associated antigen A3. Traditionally, non-small-cell lung cancer has not been considered a good target for immunotherapy due to lack of immunogenicity and the strong presence of regulatory T cells, which do not allow an adequate immune response in the host. EGF vaccination is a novel area of immunotherapy for this disease. Thus far, there has been success in generating immune and clinical responses with this vaccine in several clinical trials, and we will review in depth the efficacy and toxicity of this novel agent.     

Increased resistance to Doxorubicin in human non-small-cell lung carcinomas with metallothionein expression

Ninety-four human non-small cell lung carcinomas (NSCLC) of previously untreated patients were analyzed for the presence of metallothionein (MT) expression by means of immunohistochemistry. Of the tumors investigated, expression of MT was detected in 63%. The expression of MT was correlated with the results of doxorubicin resistance of the tumors in vitro. A significant relationship between MT expression and doxorubicin resistance was found (p=0.01). Significant correlations also exist between MT and P-glycoprotein or glutathione-S-transferase-pi expression respectively (p<0.005).     

p53 gene aberrations in non-small-cell lung carcinomas from a smoking population.

We examined 46 non-small-cell lung carcinomas (NSCLCs) for the presence of p53 mutations in exons 4-9, positive p53 immunostaining and loss of heterozygosity (LOH) in the TP53 locus. p53 mutations were detected in 13 tumour samples (28.3%), whereas overexpression of the p53 protein was found in 30 of 45 (67%) samples. Allelic loss was found in 9 of 38 (23.6%) informative cases. The statistical analysis revealed no significant correlation between p53 mutations and clinicopathological data, although mutations appear to occur more frequently in squamous cell carcinomas (7 of 18) than in adenocarcinomas (2 of 15). All but three individuals in this study group smoked. In contrast to previous reports, we found a higher prevalence of GC-->AT transitions than of GC-->TA transversions, as expected in a smoking population. A trend was found between p53-positive immunostaining and a history of heavy smoking (76-126 pack-years) and was inversely correlated with allelic deletion (LOH) at the TP53 locus. Eight of the 12 NSCLCs containing p53 mutations also had concomitant p53 overexpression, and it is of specific note that three of the four tumours containing p53 ''mutations'' with no overexpression of the p53 protein had either insertions or deletions in the p53 gene. No correlation was found between p53 mutations and fractional allele loss or ras mutations. p53 mutations in this Merseyside population in the UK do not appear to be as common as in other reports for NSCLC and exhibit predominance of GC-->AT transitions preferentially at non-CpG sites, suggesting that other carcinogens in addition to those in tobacco smoke may be involved in NSCLC in the Merseyside area of the UK.     

High-dose methotrexate with citrovorum factor rescue in non-small-cell lung cancer

Summary Nineteen patients with non-small-cell carcinoma of the lung were treated with high-dose methotrexate and leucovorin rescue. Two partial responses (10.5%) were observed, lasting 13 and 17 weeks. Toxicity was acceptable. It is concluded that the occasional benefit of high-dose methotrexate with leucovorin rescue at this dose and according to the schedule described for these patients does not warrant further study.     

表皮生长因子受体抑制剂在非小细胞肺癌治疗中的应用

特异性阻断肿瘤生长的表皮生长因子受体（EGFR）抑制剂在非小细胞肺癌（NSCLC）的治疗中具有极大潜力。目前，有两种通过修正细胞内外酪氨酸激酶信号传导过程来达到阻断此信号传导通路的治疗方法已被应用于NSCLC的治疗中。现以吉非替尼、西妥昔单抗等药物为例，综述EGFR抑制剂在NSCLC治疗中单独及与化疗或其他靶向治疗药物联合应用的临床研究进展。     

Cyclooxygenase-2 modulates the insulin-like growth factor axis in non-small-cell lung cancer

Constitutive overexpression of cyclooxygenase-2 (COX-2) occurs frequently in several different malignancies, including lung, colon, breast, and prostate cancer. Clinical studies have established elevated serum insulin-like growth factor (IGF-I) content and IGF-I:IGF-binding protein 3 (IGFBP-3) ratio as risk factors for these same malignancies. Therefore, we sought to determine the link between COX-2 expression and the IGF axis in COX-2 gene-modified human non-small-cell lung cancer (NSCLC) cells. Overexpression of COX-2 in NSCLC cells enhanced the antiapoptotic and mitogenic effects of IGF-I and IGF-II, facilitated the autophosphorylation of the type 1 IGF receptor, increased class IA phosphatidylinositol 3'-kinase activity, and decreased expression of IGFBP-3. Thus, these findings show that COX-2 augments the stimulatory arm of the IGF axis.     

表皮生长因子受体抑制剂在非小细胞肺癌治疗中的应用

特异性阻断肿瘤生长的表皮生长因子受体(EGFR)抑制剂在非小细胞肺癌(NSCLC)的治疗中具有极大潜力。目前,有两种通过修正细胞内外酪氨酸激酶信号传导过程来达到阻断此信号传导通路的治疗方法已被应用于NSCLC的治疗中。现以吉非替尼、西妥昔单抗等药物为例,综述EGFR抑制剂在NSCLC治疗中单独及与化疗或其他靶向治疗药物联合应用的临床研究进展。     

Epidermal growth factor receptor inhibitors in the treatment of non-small-cell lung cancer.

Remarkable developments in the systemic treatment of advanced non-small-cell lung cancer have taken place in the past few years. Targeted therapies have been largely employed in patients with far advanced disease, and some of them have demonstrated consistent activity in this setting. Epidermal growth factor receptor (EGFR) inhibitors cause dramatic response in approximately 10% of white patients who had received prior chemotherapy. Responses are higher in Asians. These findings are at least partly caused by the substantially higher incidence of EGFR mutations in Asians compared with whites. Studies of EGFR inhibitors in combination chemotherapy in front-line therapy of advanced non-small-cell lung cancer have, however, failed to improve survival, and better understanding of interactions between chemotherapeutic agents and EGFR inhibitors will be essential in the development of more effective strategies.     

Frequent expression of the vascular endothelial growth factor in human non-small-cell lung cancers

BACKGROUND: Angiogenesis is an essential factor for progression and metastases in solid tumors. It has been reported that several angiogenic factors play a role in the regulation of angiogenesis. Vascular endothelial growth factor (VEGF) is one of the most important molecules in angiogenesis. We investigated expressions of VEGF in a series of lung carcinomas with regard to clinicopathological factors. METHOD: VEGF expression was investigated by use of immunohistochemical studies and Northern blot analysis, using 155 primary and 26 metastatic lung carcinomas for the immunohistochemical studies and 10 primary and two metastatic lung carcinomas for the Northern blot analysis. All lesions were resected at surgery. RESULTS: The frequencies for positive VEGF expression were 64 of 74 (86.5%) adenocarcinomas, 38 of 67 (56.7%) squamous cell carcinomas, four of four (100%) large cell carcinomas, two of three (66.7%) adenosquamous carcinomas and one of five (20%) small-cell carcinomas, the degree of positivity generally being greater in well differentiated tumors. The majority of metastatic foci from adenocarcinomas and squamous cell carcinomas at other sites were also positive (76.5 and 66.7%, respectively). VEGF expression did not correlate with clinicopathological factors such as tumor size or pathological stage, but pathological stage I adenocarcinoma cases positive for VEGF demonstrated a shorter disease-free period when followed up for 48 months than those cases expressing VEGF negatively. CONCLUSIONS: The results indicated that VEGF expression was frequently detected in non-small-cell lung cancers and suggested that VEGF might relate to the disease-free period of the patients with early adenocarcinomas.      

Analysis of T-cell-receptor beta-chain-gene usage in peripheral-blood and tumor-infiltrating lymphocytes from human non-small-cell lung carcinomas

Non-small-cell lung cancers (NSCLC) are often infiltrated by T lymphocytes. It is postulated that the presence of tumor-infiltrating lymphocytes (TIL) reflects a local host immune response against autologous tumors. To identify the nature of NSCLC TIL, we have characterized the molecular structure of the TCRbeta chain expressed by infiltrating T cells and paired PBL from 9 untreated patients (4 LLC, 3 ADC and 2 SCC). For this purpose, we have used a high-resolution PCR-based method that determines CDR3 size patterns in TCRVbeta sub-families in fresh tumors and their corresponding autologous PBL samples. Oligoclonality in T-cell populations was observed in 3 (Hor, Bla and Pub) out of 9 tumor biopsies analyzed. In contrast, the TCR repertoire of the 6 following patients as well as of all the autologous PBL was diverse, with virtually all Vbeta specificities expressed. Among the 3 tumors with dominant T-cell clonotypes, relative expansion of some T-cell sub-populations was observed. One patient (Hor) with significant TCRVbeta21 expansion in tumor compared with autologous PBL, showed over-expression of a particular TCRVbeta chain with unique Vbeta21-D-Jbeta2.7 junctional region not detected in autologous PBL. TCRVbeta21/Jbeta2.7 expansion was also observed in IL-2-stimulated TIL cell lines and was confirmed by sequencing analysis of the V-D-J junctional region. These results strengthen the view that local antigen-driven selection may occur, and support the hypothesis that anti-tumor immune response may take place in some NSCLC.