Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0006142 (breast cancer)
 160,383 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Overexpression of HER-2/neu confers cellular resistance to tumor necrosis factor (TNF)-mediated cytotoxicity to SKBR-3 breast cancer cell lines. To understand the correlation between HER-2/neu expression and TNF resistance, we examined the unique signaling pathways associated with the cytotoxic effects of the immunocytokine scFv23/TNF, recombinant single-chain antibody fusion constructs containing TNF and targeting HER-2/neu, in TNF-resistant SKBR-3-LP cells. We found that treatment of HER-2/neu-overexpressing SKBR-3-LP cells with scFv23/TNF resulted in a 5- to 7-fold higher level of TNF receptor-1 expression 48 hours after exposure. In addition, treatment of SKBR-3-LP cells with scFv23/TNF resulted in down-regulation of Akt phosphorylation and induced apoptosis through cleavage of caspase-8, caspase-3, and poly(ADP-ribose) polymerase. ScFv23/TNF-induced cytotoxicity was inhibited by blocking of the binding of the TNF component of scFv23/TNF to TNF receptor-1 and was dependent on activation of caspase-8 and caspase-3. These results indicate that the immunocytokine scFv23/TNF sensitizes TNF-resistant HER-2/neu-overexpressing SKBR-3-LP cells to TNF-induced apoptosis via the overexpression of TNF receptor-1 and suggest that the overexpression of TNF receptor-1 plays a crucial role in TNF sensitivity in HER-2/neu-overexpressing cancer cells. ScFv23/TNF targeting the HER-2/neu may be an effective cytotoxic agent against HER-2/neu-overexpressing cancer cells, which are inherently resistant to TNF.
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PMID:The immunocytokine scFv23/TNF sensitizes HER-2/neu-overexpressing SKBR-3 cells to tumor necrosis factor (TNF) via up-regulation of TNF receptor-1. 1609 36

Caspase-associated recruitment domains (CARD) are protein-protein interaction modules found extensively in proteins that play important roles in apoptosis. One of the CARD-containing proteins, TUCAN (CARD8), was reported previously as an antiapoptotic protein with a molecular weight of 48 kDa, which was up-regulated in colon cancer cells. We identified a novel isoform of TUCAN with a molecular weight of 54 kDa. The new variant of TUCAN, termed TUCAN-54, was expressed in gastric, colon, and breast cancer tissues but was barely detected in normal noncancerous tissues, whereas 48-kDa TUCAN was detected in tumor tissues and noncancerous tissues. To know the function of TUCAN-54 in the apoptosis of cancer cells, TUCAN-54 was overexpressed in tumor cells by gene transfection. Its overexpression inhibited pro-caspase-9 activation, leading to the suppression of the cell death induced by a protein kinase inhibitor, staurosporine, or a chemotherapeutic reagent, etoposide (VP-16). In contrast, specific small interfering RNA-mediated suppression of TUCAN-54 expression in tumor cells increased the VP-16-induced cell death rate, indicating that expression of TUCAN-54 might be associated with chemoresistance of tumor cells. In addition, it inhibited caspase-8 activation as well, thereby suppressing Fas-induced cell death. It was revealed that Fas-associated death domain was physically associated with TUCAN-54 but not with 48-kDa TUCAN. Thus, TUCAN-54 might be a novel tumor-specific antiapoptotic molecule expressed in a variety of human cancer tissues, which might aggravate malignant potential of cancer cells, such as chemoresistance and immunoresistance.
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PMID:A novel isoform of TUCAN is overexpressed in human cancer tissues and suppresses both caspase-8- and caspase-9-mediated apoptosis. 1620 39

Chemotherapy has been used for treatment of breast cancer but with limited success. We characterized the effects of bcl-2 antisense and cisplatin combination therapy in two human isogenic breast carcinoma cells p53(+)MCF-7 and p53(-)MCF-7/E6. The transferrin-facilitated lipofection strategy we have developed yielded same transfection efficiency in both cells. Bcl-2 antisense delivered with this strategy significantly induced more cell death, apoptosis, and cytochrome c release in MCF-7/E6 than in MCF-7, but did not affect Fas level in both cells and activated caspase-8 equally. Cisplatin exerted same effects on cell viability and apoptosis in both cells, but released smaller amounts of cytochrome c while activated more caspase-8 in MCF-7/E6. The combination treatment yielded greater effects on cell viability, apoptosis, cytochrome c release, and caspase-8 activation than individual treatments in both cells although p53(-) cells were more sensitive. The potentiated activation of caspase-8 in the combination treatment suggested that caspase-8-mediated (but cytochrome c-independent) apoptotic pathway is the major contributor of the enhanced cell killing. Thus, bcl-2 antisense delivered with transferrin-facilitated lipofection can achieve the efficacy of killing breast cancer cells and sensitizing them to chemotherapy. Bcl-2 antisense and cisplatin combination treatment is a potentially useful therapeutic strategy for breast cancer irrespective of p53 status.
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PMID:BCL-2 antisense and cisplatin combination treatment of MCF-7 breast cancer cells with or without functional p53. 1622 92

We have recently demonstrated the antiproliferative and apoptotic activities of herbal traditional Chinese medicines, including the analomous fruit extract of Gleditsia sinensis, the fresh juice of Scutellaria barbata and the warmed water extract of Radix Sophorae Tonkinensis on a series of human carcinoma cells. Here, we further report the potential anti-cancer activity of the warmed water extract of Brucea javanica (BJE). Four cancer cell lines, including A549 non-small cell lung cancer, Hep3B hepatocellular carcinoma, MDA-MB231 breast cancer and SLMT-1 oesophageal squamous cell carcinoma, were incubated with BJE and strong apoptotic induction was observed under inverted microscopic investigation for all of the four cell lines tested. Using the MDA-MB231 breast cancer cell line as an experimental model, additional analyses supported the hypothesis that the mitochondrial membrane potential depolarization pathway was induced by BJE. The APO-1/Fas receptor death induction pathway was not activated under the influence of BJE, as studied by staining with Fas ligand and Fas receptor specific antibodies. Accordingly, only weak activation of caspase 8 was observed upon BJE treatment. On the other hand, caspase 3 activity was stimulated up to five-fold in BJE-treated cells compared to untreated controls. Oligonucleosomal DNA fragmentation formation was detected by labelling the nucleic acid ladders with TdT-mediated dUTP nick end labelling. Collectively, BJE-induced cancer cell death proceeds through a mitochondrial dependent pathway associated with caspase 3 activation.
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PMID:Antiproliferative and apoptosis-inducing activity of Brucea javanica extract on human carcinoma cells. 1627

Trichosanthis kirilowii MAXIM has been used as a folk remedy to treat diabetes, leukemia, and breast cancer. In the present study, the apoptotic mechanism of the methylene chloride fraction of Trichosanthis Fructus (MCTF) was investigated in human leukemic U937 cells. MCTF exhibited antiproliferative effectsagainst U937 cells (IC50=ca. 8 microg/ml). Apoptotic bodies were observed in MCTF-treated U937 cells in the TUNEL assay. We also confirmed that MCTF significantly increases annexin V(+)/propidium iodide-cells using FACS analysis. MCTF treatment activated caspase-8, -9 and -3, and led to cleaved poly (ADP-ribose) polymerase and release of cytochrome c into cytosol in a concentration-dependent manner, while MCTF did not affect Bax or Bcl-2 protein levels as shown by Western blot analysis. Taken together, these results indicate that MCTF can induce apoptosis in U937 cells chiefly via a mitochondrial-mediated pathway and suggest that Trichosanthis Fructus can be used in cancer treatment as a chemopreventive agent.
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PMID:The methylene chloride fraction of Trichosanthis Fructus induces apoptosis in U937 cells through the mitochondrial pathway. 1639 3

The dose-dependent cardiotoxicities of doxorubicin (DOX) significantly limits its anti-cancer efficacies. One of the ways to augment the efficacies of DOX at a relatively low cumulative dose is to use a chemical sensitizer. Here, we demonstrated that schisandrin B (Sch B) significantly enhanced DOX-induced apoptosis of SMMC7721, a human hepatic carcinoma cell line, and of MCF-7, a human breast cancer cell line. This enhancement was irrelevant to the action of Sch B on P-glycoprotein or other drug-transporters, but associated with the activation of caspase-9 rather than caspase-8. The loss of mitochondria membrane potential was observed when cells were treated with DOX and Sch B combined. On the other hand, at the same experimental conditions, Sch B did not enhance the DOX-induced apoptosis of primary rat cardiomyocytes and primary human fibroblasts. Therefore, it is speculative that Sch B may bring benefit to clinical chemotherapy by reducing significantly the cumulative doses of DOX and its associated cardiotoxicities.
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PMID:Schisandrin B enhances doxorubicin-induced apoptosis of cancer cells but not normal cells. 1640 22

While the apoptosis-inducing ligand Apo2L/TRAIL is a promising new agent for the treatment of cancer, the sensitivity of cancer cells for induction of apoptosis by Apo2L/TRAIL varies considerably. Identification of agents that can be used in combination with Apo2L/TRAIL to enhance apoptosis in breast cancer cells would increase the potential utility of this agent as a breast cancer therapeutic. Here, we show that the histone deacetylase inhibitor, suberoylanilide hydroxamic acid (SAHA), can sensitize Apo2L/TRAIL-resistant breast cancer cells to Apo2L/TRAIL-induced apoptosis. Importantly, neither Apo2L/TRAIL alone, nor in combination with SAHA, affected the viability of normal human cells in culture. Apo2L/TRAIL-resistant MDA-MB-231 breast cancer cells, generated by long-term culture in the continuous presence of Apo2L/TRAIL, were resensitized to Apo2L/TRAIL-induced apoptosis by SAHA. The sensitization of these cells by SAHA was accompanied by activation of caspase 8, caspase 9 and caspase 3 and was concomitant with Bid and PARP cleavage. The expression of the proapoptotic protein, Bax, increased significantly with SAHA treatment and high levels of Bax were maintained in the combined treatment with Apo2L/TRAIL. Treatment with SAHA increased cell surface expression of DR5 but not DR4. Interestingly, SAHA treatment also resulted in a significant increase in cell surface expression of DcR1. Taken together, our findings indicate that the use of these 2 agents in combination may be effective for the treatment of breast cancer.
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PMID:The histone deacetylase inhibitor, suberoylanilide hydroxamic acid, overcomes resistance of human breast cancer cells to Apo2L/TRAIL. 1655 Jun 2

Breast cancer is one of the most common malignancies diagnosed in women and it is increasing in incidence. Siegesbeckia glabrescens (SG) has been used in traditional oriental medicine to treat cardiovascular diseases such as hypertension and angina pectoris. This study examined whether or not SG could induce apoptosis in human breast carcinoma cells. The treatment of estrogen-receptor (ER)-positive (MCF-7) and ER-negative (MDA-MB-231) cells with a variety of SG concentrations (0-1.0 mg/ml) resulted in a dose-dependent sequence of events that were marked by apoptosis. Furthermore, this apoptosis was accompanied by the cleavage of procaspase-9 and -3, and poly(ADP-ribose) polymerase (PARP) in the MCF-7 cells, and procaspase-8 and -3 and PARP in the MDA-MB-231 cells. Although, the SG-induced apoptosis was associated with a decrease in the level of Bcl-2 mRNA expression and an increase in the level of Bax mRNA expression in MCF-7 cells, there was no detectable change in the MDA-MB-231 cells. This suggests that SG might exert anti-proliferative action in human breast carcinoma cells via two different apoptotic pathways, namely an intrinsic signal in MCF-7 cells and an extrinsic signal in MDA-MB-231 cells. Therefore, regardless of the ER status, SG might be a promising pro-apoptotic agent for treating breast cancer.
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PMID:Siegesbeckia glabrescens induces apoptosis with different pathways in human MCF-7 and MDA-MB-231 breast carcinoma cells. 1668 80

The epidermal growth factor (EGF) receptor (EGFR) plays an important role in the growth and progression of breast cancer. Overexpression of EGFR or the high activity of EGFR signal pathway has been related with increases in cell proliferation and a poor prognosis in patients with breast cancer. Several human breast cancer cell lines depend on estrogen for their proliferation. EGF may bypass the requirement of estrogen for the proliferation of breast cancer cells. To evaluate this hypothesis, MCF-7 breast cancer cells were stimulated with EGF and the effects on cell proliferation, signal pathways, and cell cycle progression were determined. The results demonstrate that EGF stimulation in the absence of others growth factors induced a modest effect on cell proliferation and the induction of a cellular arrest in the G(1) phase of the cell cycle. Although phosphorylation of AKT and ERK proteins were detected, this phosphorylation was insufficient to support of cell cycle progression. Cellular arrest in G(1) phase was accompanied by an increase in p21(CIP1) protein, down regulation of the BCL-2 protein, induction of caspase-8, and ARHI/NOEY2 an imprinted tumor suppressor gene. These results indicate that EGFR activation by itself is not sufficient for the proliferation of breast cancer cells and suggest the existence of a mechanism that induces apoptosis upon EGFR activation.
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PMID:Cell death of MCF-7 human breast cancer cells induced by EGFR activation in the absence of other growth factors. 1686 4

The cyclin-dependent kinase inhibitor flavopiridol is undergoing clinical trials as an antitumor drug. We show here that pretreatment of different human breast cancer cell lines with flavopiridol facilitates tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis. In breast tumor cells, apoptosis induction by TRAIL is blocked at the level of apical caspase-8 activation. Flavopiridol treatment enhances TRAIL-induced formation of death-inducing signaling complex and early processing of procaspase-8. Subsequently, a TRAIL-induced, mitochondria-operated pathway of apoptosis is activated in cells treated with flavopiridol. Down-regulation of cellular FLICE-inhibitory proteins (c-FLIP; c-FLIP(L) and c-FLIP(S)) is observed on flavopiridol treatment. c-FLIP loss and apoptosis sensitization by flavopiridol are both prevented in cells treated with an inhibitor of the ubiquitin-proteasome system. Furthermore, targeting c-FLIP directly with small interfering RNA oligonucleotides also sensitizes various human breast tumor cell lines to TRAIL-induced apoptosis. Our results indicate that flavopiridol sensitizes breast cancer cells to TRAIL-induced apoptosis by facilitating early events in the apoptotic pathway, and this combination treatment could be regarded as a potential therapeutic tool against breast tumors.
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PMID:Flavopiridol induces cellular FLICE-inhibitory protein degradation by the proteasome and promotes TRAIL-induced early signaling and apoptosis in breast tumor cells. 1695 Dec 3


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