SRC gene expression in human cancer: the role of transcriptional activation

v-Src oncogene product increases sphingosine kinase 1 expression through mRNA stabilization: alteration of AU-rich element-binding proteins

Sphingosine kinase 1 (SPHK1) is overexpressed in solid tumors and leukemia. However, the mechanism of SPHK1 overexpression by oncogenes has not been defined. We found that v-Src-transformed NIH3T3 cells showed a high SPHK1 mRNA, SPHK1 protein and SPHK enzyme activity. siRNA of SPHK1 inhibited the growth of v-Src-NIH3T3, suggesting the involvement of SPHK1 in v-Src-induced oncogenesis. v-Src-NIH3T3 showed activations of protein kinase C-alpha, signal transducers and activators of transcription 3 and c-Jun NH(2)-terminal kinase. Their inhibition suppressed SPHK1 expression in v-Src-NIH3T3, whereas their overexpression increased SPHK1 mRNA in NIH3T3. Unexpectedly, the nuclear run-on assay and the promoter analysis using 5'-promoter region of mouse SPHK1 did not show any significant difference between mock- and v-Src-NIH3T3. Furthermore, the half-life of SPHK1 mRNA in mock-NIH3T3 was nearly 15 min, whereas that of v-Src-NIH3T3 was much longer. Examination of two AU-rich region-binding proteins, AUF1 and HuR, that regulate mRNA decay reciprocally, showed decreased total AUF1 protein associated with increased tyrosine-phosphorylated form and increased serine-phosphorylated HuR protein in v-Src-NIH3T3. Modulation of AUF1 and HuR by their overexpression or siRNA revealed that SPHK1 mRNA in v-Src- and mock-NIH3T3 was regulated reciprocally by these factors. Our results showed, for the first time, a novel mechanism of v-Src-induced SPHK1 overexpression.

New strategies for the treatment of metastatic bone disease

The introduction of bisphosphonates represents an important advance in the care of patients with metastatic bone disease. Nonetheless, we remain unable to prevent metastatic bone destruction. This review will discuss several novel therapies, including inhibitors of receptor activator of nuclear factor-kappabeta, c-Src, mammalian target of rapamycin, cathepsin K, and alpha(5)beta(3) integrins, which could improve our control over this devastating complication.

Multiple oncogenic pathway signatures show coordinate expression patterns in human prostate tumors

Background

Gene transcription patterns associated with activation of oncogenes Myc, c-Src, beta-catenin, E2F3, H-Ras, HER2, EGFR, MEK, Raf, MAPK, Akt, and cyclin D1, as well as of the cell cycle and of androgen signaling have been generated in previous studies using experimental models. It was not clear whether genes in these “oncogenic signatures” would show coordinate expression patterns in human prostate tumors, particularly as most of the signatures were derived from cell types other than prostate.

Principal Findings

The above oncogenic pathway signatures were examined in four different gene expression profile datasets of human prostate tumors (representing ∼250 patients in all), using both Q1-Q2 and one-sided Fisher's exact enrichment analysis methods. A significant fraction (∼5%) of genes up-regulated experimentally by Myc, c-Src, HER2, Akt, or androgen were co-expressed in human tumors with the oncogene or biomarker corresponding to the pathway signature. Genes down-regulated experimentally, however, did not show anticipated patterns of anti-enrichment in the human tumors.

Conclusions

Significant subsets of the genes in these experimentally-derived oncogenic signatures are relevant to the study of human prostate cancer. Both molecular biologists and clinical researchers could focus attention on the relatively small number of genes identified here as having coordinate patterns that arise from both the experimental system and the human disease system.

Histone deacetylase inhibitors: mechanisms and clinical significance in cancer: HDAC inhibitor-induced apoptosis

Epigenic modifications, mainly DNA methylation and acetylation, are recognized as the main mechanisms contributing to the malignant phenotype. Acetylation and deacetylation are catalyzed by specific enzymes, histone acetyltransferases (HATs) and histone deacetylases (HDACs), respectively. While histones represent a primary target for the physiological function of HDACs, the antitumor effect of HDAC inhibitors might also be attributed to transcription-independent mechanisms by modulating the acetylation status of a series of non-histone proteins. HDAC inhibitors may act through the transcriptional reactivation of dormant tumor suppressor genes. They also modulate expression of several other genes related to cell cycle, apoptosis, and angiogenesis. Several HDAC inhibitors are currently in clinical trials both for solid and hematologic malignancies. Thus, HDAC inhibitors, in combination with DNA-demethylating agents, chemopreventive, or classical chemotherapeutic drugs, could be promising candidates for cancer therapy. Here, we review the molecular mechanisms and therapeutic potential of HDAC inhibitors for the treatment of cancer.

Stroma-derived matrix metalloproteinase (MMP)-2 promotes membrane type 1-MMP-dependent tumor growth in mice

Matrix metalloproteinase-2 (MMP-2) is a stroma-derived MMP belonging to the type IV collagenase family. It is believed to mediate tumor cell behavior by degrading deposits of type IV collagen, a major component of the basement membrane. The membrane type 1-MMP (MT1-MMP) is a highly potent activator of MMP-2 and is expressed in many tumor and stromal cells. However, the roles played by stromal MMP-2 in tumor progression in vivo remain poorly understood. We established a colon epithelial cell line from an Mt1-mmp(-/-) mouse strain and transfected these cells with an inducible expression system for MT1-MMP (MT1rev cells). Following s.c. implantation into Mmp-2(+/+) mice and induction of MT1-MMP expression, MT1rev cells grew rapidly, whereas they grew very slowly in Mmp-2(-/-) mice, even in the presence of MT1-MMP. This MT1-MMP-dependent tumor growth of MT1rev cells was enhanced in Mmp-2(-/-) mice as long as MMP-2 was supplied via transfection or coimplantation of MMP-2-positive fibroblasts. MT1rev cells cultured in vitro in a three-dimensional collagen gel matrix also required the MT1-MMP/MMP-2 axis for rapid proliferation. MT1rev cells deposit type IV collagen primarily at the cell-collagen interface, and these deposits seem scarce at sites of invasion and proliferation. These data suggest that cooperation between stroma-derived MMP-2 and tumor-derived MT1-MMP may play a role in tumor invasion and proliferation via remodeling of the tumor-associated basement membrane. To our knowledge, this is the first study demonstrating that MT1-MMP-dependent tumor growth in vivo requires stromal-derived MMP-2. It also suggests that MMP-2 represents a potential target for tumor therapeutics.

Cellular transformation and activation of the phosphoinositide-3-kinase-Akt cascade by the ETV6-NTRK3 chimeric tyrosine kinase requires c-Src

The ETV6-NTRK3 (EN) chimeric tyrosine kinase, a potent oncoprotein expressed in tumors derived from multiple cell lineages, functions as a constitutively active protein-tyrosine kinase. ETV6-NTRK expression leads to the constitutive activation of two major effector pathways of wild-type NTRK3, namely, the Ras-mitogen-activated protein kinase (MAPK) mitogenic pathway and the phosphoinositide-3-kinase (PI3K)-Akt pathway mediating cell survival, and both are required for EN transformation. However, it remains unclear how ETV6-NTRK3 activates Ras-Erk1/2 and/or PI3K-Akt cascades. Here, we define some aspects of the molecular mechanisms regulating ETV6-NTRK-dependent Ras-Erk1/2 and PI3K-Akt activation. We show that ETV6-NTRK3 associates with c-Src, and that treatment with SU6656, a c-Src inhibitor, completely blocks ETV6-NTRK-transforming activity. Treatment of NIH3T3 cells expressing ETV6-NTRK3 with SU6656 attenuated the activation of Ras-Erk1/2 and PI3K-Akt. Suppression of c-Src by RNA interference in NIH3T3-ETV6-NTRK3 cells resulted in markedly decreased expression of cyclin D1 and suppression of activation of Ras-Erk1/2 and PI3K-Akt. However, in Src-deficient cells, the ETV6-NTRK3 failed to activate the PI3K-Atk pathway, but not the Ras-Erk1/2 pathway. Therefore, these data indicate that ETV6-NTRK3 induces the PI3K-Akt cascade through the activation of c-Src.

Overcoming resistance to molecularly targeted anticancer therapies: Rational drug combinations based on EGFR and MAPK inhibition for solid tumours and haematologic malignancies

Accumulating evidence suggests that cancer can be envisioned as a "signaling disease", in which alterations in the cellular genome affect the expression and/or function of oncogenes and tumour suppressor genes. This ultimately disrupts the physiologic transmission of biochemical signals that normally regulate cell growth, differentiation and programmed cell death (apoptosis). From a clinical standpoint, signal transduction inhibition as a therapeutic strategy for human malignancies has recently achieved remarkable success. However, as additional drugs move forward into the clinical arena, intrinsic and acquired resistance to "targeted" agents becomes an issue for their clinical utility. One way to overcome resistance to targeted agents is to identify genetic and epigenetic aberrations underlying sensitivity/resistance, thus enabling the selection of patients that will most likely benefit from a specific therapy. Since resistance often ensues as a result of the concomitant activation of multiple, often overlapping, signaling pathways, another possibility is to interfere with multiple, cross-talking pathways involved in growth and survival control in a rational, mechanism-based, fashion. These concepts may be usefully applied, among others, to agents that target two major signal transduction pathways: the one initiated by epidermal growth factor receptor (EGFR) signaling and the one converging on mitogen-activated protein kinase (MAPK) activation. Here, we review the molecular mechanisms of sensitivity/resistance to EGFR inhibitors, as well as the rationale for combining them with other targeted agents, in an attempt to overcome resistance. In the second part of the paper, we review MAPK-targeted agents, focusing on their therapeutic potential in haematologic malignancies, and examine the prospects for combinations of MAPK inhibitors with cytotoxic agents or other signal transduction-targeted agents to obtain synergistic anti-tumour effects.

Potential role of N-myristoyltransferase in cancer

Colorectal cancer is the second leading cause of malignant death, and better preventive strategies are needed. The treatment of colonic cancer remains difficult because of the lack of effective chemotherapeutic agents; therefore it is important to continue to search for cellular functions that can be disrupted by chemotherapeutic drugs resulting in the inhibition of the development and progression of cancer. The current knowledge of the modification of proteins by myristoylation involving myristoyl-CoA: protein N-myristoyltransferase (NMT) is in its infancy. This process is involved in the pathogenesis of cancer. We have reported for the first time that NMT activity and protein expression were higher in human colorectal cancer, gallbladder carcinoma and brain tumors. In addition, an increase in NMT activity appeared at an early stage in colonic carcinogenesis. It is conceivable therefore that NMT can be used as a potential marker for the early detection of cancer. These observations lead to the possibility of developing NMT specific inhibitors, which may be therapeutically useful. We proposed that HSC70 and/or enolase could be used as an anticancer therapeutic target. This review summarized the status of NMT in cancer which has been carried in our laboratory.

Effects of the histone deacetylases inhibitors sodium butyrate and trichostatin A on the inhibition of gap junctional intercellular communication by H2O2- and 12-O-tetradecanoylphorbol-13-acetate in rat liver epithelial cells

The histone deacetylase (HDAC) inhibitors, trichostatin A (TSA) and sodium butyrate (NaBu) are considered as potent therapeutic agents for cancer treatment presenting therapeutic benefits with less risk of side effects. The microbial metabolite, TSA is a potent reversible and highly specific inhibitor of mammalian histone deacetylases. NaBu causes hyperacetylation of core histones with effects similar to TSA but it is not a specific inhibitor of HDACs. The gap junction is a channel in the plasma membrane of most cell types which allows direct communication (gap junctional intercellular communication; GJIC) of small molecules and ions. Modulation of GJIC is a known cellular event associated with tumor promotion. The effects of NaBu and TSA on the H(2)O(2)- and 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced GJIC inhibition of WB cells and the mechanisms involved in the process were assessed. TSA and NaBu exerted differential preventive effects on the H(2)O(2) and TPA-induced inhibition of GJIC as well as hyperphosphorylation of connexin43 (Cx43) in WB-F344 rat liver epithelial cells (WB cells). NaBu prevented the TPA-induced GJIC inhibition via ERK1/2 inactivation whilst TSA restored the H(2)O(2)-induced GJIC inhibition and Cx43 hyperphosphorylation by preventing p38 MAP kinase. The inhibition of tyrosine phosphorylation and down-regulation of src protein observed may also contribute to Connexin 43 dephosphorylation and GJIC restoration by TSA and NaBu partly through depletion of src protein pool. Thus, TSA and NaBu exert differential effects on chemically induced GJIC inhibition via modulation of MAP kinases and partly, tyrosine kinases.

Inhibition of protein kinase c-Src reduces the incidence of breast cancer metastases and increases survival in mice: implications for therapy

c-Src is a proto-oncogene, belonging to the nonreceptor protein kinases family, which plays a prominent role in carcinogenesis. In this study, we tested the hypothesis that c-Src could promote breast cancer metastasis acting on several cell types and that pharmacological disruption of its kinase activity could be beneficial for the treatment of metastases. Female BALB/c-nu/nu mice were subjected to intracardiac injection of the human breast cancer cells MDA-MB-231 (MDA-231), which induced prominent bone and visceral metastases. These were pharmacologically reduced by treatment with the c-Src inhibitor [7-{4-[2-(2-methoxy-ethylamino-ethoxy]-phenyl}-5-(3-methoxy-phenyl)-7H-pyrrolo[2,3-d]pyrimidin-4-ylamine] CGP76030 (100 mg/kg/day p.o.), resulting in decreased morbidity and lethality. Metastases were more severe in mice injected with MDA-231 cells stably transfected with wild-type c-Src (MDA-231-SrcWT), whereas transfection in injected cells of a c-Src kinase-dead dominant-negative construct (MDA-231-SrcDN) resulted in reduced morbidity, lethality, and incidence of metastases similar to the mice treated with the inhibitor. An analogous beneficial effect of c-Src inhibition was observed in subcutaneous and intratibial implanted tumors. In vitro, c-Src suppression reduced MDA-231 cell aggressiveness. It also impaired osteoclast bone resorption both directly and by reducing expression by osteoblasts of the osteoclastogenic cytokines interleukin-1beta and interleukin-6, whereas parathyroid hormone-related peptide was not implicated. c-Src was also modestly but consistently involved in the enhancement of endothelial cell proliferation in vitro and angiogenesis in vivo. In conclusion, we propose that c-Src disruption affects the metastatic process and thus is a therapeutic target for the treatment of breast cancer.

Copper(II) and manganese(III) complexes of N'-[(2-hydroxy phenyl) carbonothioyl] pyridine-2-carbohydrazide: novel therapeutic agents for cancer

c-Src is a non-receptor tyrosine kinase which plays a significant role in the growth mediated signaling pathway impacting cellular proliferation, differentiation, mobility, survival and transformation. Myristoylation of pp60(c-src) leads to its membrane association and activation, a process catalyzed by N-myristoyltransferase (NMT). We have shown earlier increased NMT activity in the early stages of colon cancer. A novel sulfur nitrogen donor ligand and its Cu(II) and Mn(III) complexes have been prepared and characterized using various physicochemical analyses. These Cu(II) and Mn(III) complexes showed cytotoxicity against the colon cancer cell line HT29. The IC(50) for Cu(II) and Mn(III) complexes were 12.2 and 16.1 microM, respectively. HT29 cells treated with Cu(II) and Mn(III) complexes induced apoptosis and inhibited endogenous NMT activity. Furthermore, they induced higher levels of hsc70 and inhibited the expression of c-Src. Inhibition of endogenous NMT activity by metal complexes was demonstrated for the first time. This study also suggested that NMT activity is crucial for cell survival and demonstrated that cessation in activity results in apoptosis. These metal complexes may prove to be novel therapeutic agents for cancer targeting NMT.

Histone deacetylase inhibitor depsipeptide represses nicotinamide N-methyltransferase and hepatocyte nuclear factor-1beta gene expression in human papillary thyroid cancer cells

Nicotinamide N-methyltransferase (NNMT) catalyzes N-methylation of nicotinamide and other structural analogues. NNMT gene expression is enhanced in many papillary thyroid cancer cells and activated by hepatocyte nuclear factor (HNF)-1beta. In this work, we studied the effects of depsipeptide, a histone deacetylase inhibitor, on NNMT gene expression in BHP 18-21 papillary thyroid cancer cells. Depsipeptide reduced NNMT mRNA level in a dose-dependent and time-dependent manner as determined by semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR). In contrast, expression of the sodium iodide symporter (NIS), a gene with differentiated function, waas enhanced in the treated cells. NNMT protein level determined by Western blot analysis and NNMT catalytic activity was also reduced significantly in the depsipeptide-treated cells. To study the mechanism of NNMT gene repression by depsipeptide, effects of depsipeptide on NNMT promoter activity were determined by luciferase reporter gene assay. NNMT promoter activity was significantly reduced in the HNF-1beta-positive BHP 18-21 cells but not in the HNF-1beta-negative BHP 14-9 papillary cancer cells. A mutant reporter construct with mutations in a HNF-1 site in the NNMT basal promoter region did not respond to depsipeptide in both HNF-1beta protein levels, and abolished activity of DNA binding to the HNF-1 site in the NNMT promoter region. Protein synthesis inhibitor cycloheximide and proteasome inhibitor MG-132 enhanced HNF-1beta stability in the depsipeptide-treated cells. In summary, depsipeptide represses NNMT and HNF-1beta gene expression in some papillary thyroid cancer cells. the repression of NNMT by depsipeptide is at the transcription level through downregulation of transcription activator HNF-1beta.

Serum epidermal growth factor receptor/HER-2 predicts poor survival in patients with metastatic breast cancer

BACKGROUND

Epidermal growth factor receptor (EGFR, HER-1, and erbB1) is overexpressed in primary breast cancer and had been identified as a poor prognostic factor.

METHODS

Pretreatment serum EGFR levels were quantified by using an enzyme-linked immunoadsorbent assay in a Phase III first-line trial of letrozole and tamoxifen and were correlated with patient outcomes.

RESULTS

Serum EGFR levels in a control group of 117 healthy, postmenopausal women measured 64.1 +/- 13.3 ng/mL (mean +/- standard deviation). Using a cutoff EGFR level of 44.1 ng/mL from the control group (5% nonparametric method), 53 of 535 patients (10%) had decreased serum levels of EGFR. Patients with decreased serum EGFR had no significant difference in objective response rate (ORR), clinical benefit rate (CBR), time to progression (TTP), or time to treatment failure (TTF); however, they did have significantly reduced survival compared with patients who had normal serum EGFR levels (median survival, 23.3 months vs. 30.9 months; P = .007). A combined analysis of pretreatment serum EGFR and HER-2 yielded no additional predictive information for ORR, CBR, TTP, or TTF compared to serum HER-2 alone. However, in the current analysis, a subgroup of patients who had decreased serum EGFR and normal serum HER-2 was identified (n = 39 of 535 patients; 7.3%) that had significantly reduced survival compared with patients who had normal serum levels of both EGFR and HER-2 (median survival, 23.5 months vs. 37.1 months; P = .005). In multivariate analysis, a decreased serum EGFR level remained a significant independent prognostic factor for decreased survival (hazards ratio, 1.58; P = .007).

CONCLUSIONS

In patients who had metastatic breast cancer, decreased serum EGFR/normal serum HER-2 predicted shorter survival compared with patients who had normal levels of serum EGFR/HER-2. This patient subgroup deserves further study to assess their response to and selection for anti-EGFR-directed therapies.

Histone acetylation in reproductive organs: Significance of histone deacetylase inhibitors in gene transcription

Acetylation of histones is cooperatively regulated by two groups of enzymes, histone acetyltransferases and histone deacetylases. Histone acetylation status plays a fundamental role in the level of gene transcription; numerous studies have demonstrated that histone deacetylase inhibitors cause cell growth arrest, apoptosis, and differentiation in various cells including human mammary gland and endometrial cells by altering transcription of a small number of genes. A recent study has also shown that a highly acetylated histone status alters cell motility. After the present review of the published reports on the mechanisms underlying histone acetylation and in vitro effects of histone deacetylase inhibitors, we conclude that this class of agents may have potential not only as anticancer drugs, but also as inducers of differentiation and/or motility for benign gynecologic conditions such as endometriosis and disorders of endometrial differentiation and dysfunction. (Reprod Med Biol 2005; 4: 115-122).

Expression of N-myristoyltransferase in human brain tumors

N-myristoylation is a process of covalent irreversible protein modification that promotes association of proteins with membranes. Based on our previous findings of elevated N-myristoyltransferase (NMT) activity in colonic epithelial neoplasms that appears at an early stage in colonic carcinogenesis, together with elevated NMT expression in human colorectal and gallbladder carcinomas, we investigated NMT activity and protein expression of NMT1 and NMT2 in human brain tumors and documented elevated NMT activity and higher protein expressions. For the first time, we have demonstrated that NMT has the potential to be used as a marker of human brain tumors. However, further studies with larger number of patients are required to establish its role as a complementary diagnostic tool. This finding has significant implications for further understanding of biological mechanisms involved in tumorigenesis, as well as for diagnosis and therapy of human brain tumors.

Molecular Mechanisms of Resistance to Therapies Targeting the Epidermal Growth Factor Receptor

Targeted therapies that inhibit the activity of tyrosine kinase receptors such as the epidermal growth factor receptor (EGFR) have shown activity against solid malignancies when used as single agents or in combination with chemotherapy. Although anti-EGFR therapies are active in some patients, eventually disease in nearly all patients will become refractory to therapy. Therefore, a better understanding of the mechanisms of resistance to anti-EGFR therapies is critical to further improve the efficacy of this class of agents. Mechanisms that mediate resistance to anti-EGFR therapies include the presence of redundant tyrosine kinase receptors, increased angiogenesis, and the constitutive activation of downstream mediators. Two recent landmark publications have also shown that specific mutations in the kinase domain of EGFR in some lung carcinomas are associated with markedly improved response rates to an EGFR tyrosine kinase inhibitor. Mutations in the EGFR receptor seem to play a significant role in determining the sensitivity of tumor cells to EGFR inhibitor therapy by altering the conformation and activity of the receptor. As the field of molecular therapeutics continues to evolve, a comprehensive understanding of resistance mechanisms will ultimately lead to refinements in our regimens to provide better care for patients with cancer.

Regulation of alternative SRC promoter usage in HepG2 hepatocellular carcinoma cells

Alternative promoters allow for increased spatial and temporal diversity in expression patterns for a single gene. The human SRC gene, encoding the non-receptor c-Src tyrosine kinase, is regulated by two alternative promoters separated by approximately 1 kb. The distal SRC1alpha promoter is tissue-restricted, while expression of the proximal SRC1A promoter appears to be ubiquitous. A barrier to elucidating the mechanisms of SRC transcriptional regulation has been the finding that the individual strengths of the SRC promoters in isolation do not match their relative strength of use seen in vivo. For example, in HepG2 hepatocellular carcinoma cells, SRC1A is significantly stronger in isolation than SRC1alpha, despite SRC1alpha being the predominant promoter used in this cell line. Previously, we have shown that HepG2 cells, as well as various colon cancer cell lines, display activated SRC transcription, which is linked to the elevated c-Src expression and activity necessary for growth and survival of these cells. These findings thus highlight the importance of understanding the mechanisms of SRC transcriptional regulation in human cancer. We hypothesize the discrepancy between individual SRC promoter strength and relative usage in vivo stems from a lack of linked promoter context. Therefore, we have developed and validated a novel dual SRC promoter reporter strategy to allow the simultaneous mechanistic study of both SRC promoters in their natural linked context. This approach has yielded evidence that SRC activation proceeds through genomic element(s) outside the promoter region in HepG2 cells. Therefore, we performed a preliminary study of DNaseI hypersensitive (DH) site composition within the SRC locus. This approach identified a HepG2-specific DH site that displayed activating potential towards the SRC1alpha promoter. These results thus provide important insight to the mechanism of SRC transcriptional activation in liver cancer cells.

Expression of methionine aminopeptidase 2, N-myristoyltransferase, and N-myristoyltransferase inhibitor protein 71 in HT29

Protein myristoylation is a co-translational process, catalyzed by N-myristoyltransferase (NMT) that occurs after the initiating methionine is removed by methionine aminopeptidase (MetAP). The enzymes NMT and MetAP play a major role in the process of myristoylation of oncoproteins including the c-src family. In this study, we examined the levels of expression of MetAP2, NMT, and NMT inhibitor protein 71 (NIP71) in human colon cancer cell lines (HCCLs). We examined the influence of cell density on the expression of the above proteins in HT29 cells. Western blot analysis of MetAP2 and NMT demonstrated higher levels of protein expression in low density of HT29 while low expression in high density was observed. In addition, we observed that NIP71 and pp60(c-src) expressions were dependent on the cell density of HT29. This is the first study demonstrating the expression of MetAP2, NMT, pp60(c-src), and NIP71 in HCCLs.