Design and synthesis of a pro-drug of vinblastine targeted at treatment of prostate cancer with enhanced efficacy and reduced systemic toxicity

Chemotherapy of prostate cancer with antimitotic agents such as vinblastine and doxorubicin is only marginally effective, due to dose-limiting systemic toxicity. Herein we report the development of peptidyl conjugate 5 of the cytotoxic agent vinblastine (1), along with the results of its in vitro and in vivo evaluation as a pro-drug targeted at prostate cancer cells. Prostate-derived tumors are known to produce significant amounts of prostate specific antigen (PSA), a serine protease with chymotrypsin-like properties. Earlier work in these laboratories established that an appropriately engineered peptidyl pro-drug will release active cytotoxic agent strictly within the microenvironment of the tumor tissue (Garsky, V. M., et al. J. Med.Chem. 2001, 44, 4216-4224). Conjugate 5, which features an octapeptide segment attached by an ester linkage at the 4-position of vinblastine (1), undergoes rapid cleavage by PSA (T(1/2) = 12 min) between the Gln and Ser residues. In nude mouse xenograft studies, 5 reduced circulating PSA levels by 99% and tumor weight by 85% at a dose just below its MTD. By contrast, the putative end-point metabolite, the cytotoxic agent des-acetyl vinblastine (1b), was ineffective in reducing PSA levels and tumor burden at its maximum tolerated doses. Additional data from metabolism studies on 5 support the supervention of a novel in vivo processing mechanism, the spontaneous release of 1b from a dipeptidyl intermediate driven by favorable diketopiperazine formation.     

Activity of MKT 077, a rhodacyanine dye, against human tumor colony-forming units.

MKT 077 is related to rhodamine 123 dye and demonstrates preferential accumulation in the mitochondria of cancer cells compared to normal cells. This difference in retention between cancer and normal cells led to the finding that MKT 077 selectively inhibits the growth of cancer cells in vitro. To define the preclinical activity profile of MKT 077, the compound was tested in vivo against a large variety of human tumors utilizing the human tumor-cloning assay. MKT 077 was studied using a sequential 2 h exposure separated by 24 h (2-24-2 h) and a 24 h exposure at final concentrations of 0.1, 0.2, 1.0, 2.0, 10.0 and 20.0 microg/ml. MKT 077 was also studied using continuous exposure at final concentrations of 0.1, 1.0 and 10 microg/ml. A decrease in tumor colony formation was considered significant if survival of colonies treated with MKT 077 was 50% or less compared to untreated controls. A total of 149 specimens was treated with MKT 077 with 51, 58 and 34 evaluable specimens with the 2-24-2 h, the 24 h and the continuous exposure, respectively. The results of the present study suggest a positive relationship between concentration and response. No relationship between exposure schedule and activity was observed. Inhibitory effects were obtained against multiple tumor types. High cytotoxic activity was obtained against breast, ovary, endometrial, colon and non-small cell lung cancer with concentrations of 2 microg/ml or above. In conclusion, the broad spectrum of cytotoxicity of MKT 077 in the human tumor-cloning assay and the unique mechanism of action of MKT 077 encourage additional preclinical and clinical studies with this compound and other rhodacyanine dyes.     

Frondoside A inhibits human breast cancer cell survival, migration, invasion and the growth of breast tumor xenografts

Breast cancer is a major challenge for pharmacologists to develop new drugs to improve the survival of cancer patients. Frondoside A is a triterpenoid glycoside isolated from the sea cucumber, Cucumaria frondosa. It has been demonstrated that Frondoside A inhibited the growth of pancreatic cancer cells in vitro and in vivo. We investigated the impact of Frondoside A on human breast cancer cell survival, migration and invasion in vitro, and on tumor growth in nude mice, using the human estrogen receptor-negative breast cancer cell line MDA-MB-231. The non-tumorigenic MCF10-A cell line derived from normal human mammary epithelium was used as control. Frondoside A (0.01-5 μM) decreased the viability of breast cancer cells in a concentration- and time-dependent manner, with 50%-effective concentration (EC50) of 2.5 μM at 24h. MCF10-A cells were more resistant to the cytotoxic effect of Frondoside A (EC50 superior to 5 μM at 24 h). In the MDA-MB-231 cells, Frondoside A effectively increased the sub-G1 (apoptotic) cell fraction through the activation of p53, and subsequently the caspases 9 and 3/7 cell death pathways. In addition, Frondoside A induced a concentration-dependent inhibition of MDA-MB-231 cell migration and invasion. In vivo, Frondoside A (100 μg/kg/dayi.p. for 24 days) strongly decreased the growth of MDA-MB-231 tumor xenografts in athymic mice, without manifest toxic side-effects. Moreover, we found that Frondoside A could enhance the killing of breast cancer cells induced by the chemotherapeutic agent paclitaxel. These findings identify Frondoside A as a promising novel therapeutic agent for breast cancer.     

Cancer stem cells and novel targets for antitumor strategies

Cancer stem cells (CSCs) were identified in human leukemias in landmark studies of John Dick and his colleagues. Subsequently, similar cancer stem-like cells were identified in solid tumors of the breast, colon, brain and other sites. CSCs have distinct markers and are highly tumorigenic compared to other subsets. They can differentiate into all the cell phenotypes of the parental tumor. Other key features include activation of pluripotency genes (Oct4, Sox2, Nanog), self-renewal, formation of tumor spheres in low-adherence cultures, and multi-drug resistance. Clinically, drug resistance is probably the most important feature, because CSCs resist conventional cancer therapies and are likely to play a major role in cancer relapse. Based on their properties, several molecules have been targeted for therapy with drugs as follows. 1) The self-renewal pathways Wnt/β-catenin, Hedgehog and Notch. 2) The aryl hydrocarbon receptor (AHR), with tranilast and other AHR agonists. 3) Cytokines and inflammatory pathways (e.g., IL-6, IL-8, NF-κB). 4) TGF-β and epithelial- to-mesenchymal transition (EMT) pathways. 5) Homing molecules involved in metastasis; most notably CXCR4 or its ligand CXCL12. 6) Growth factors, their receptors and coreceptors (such as neuropilin-1), and signaling components (e.g., tyrosine kinases). 7) Cell-surface markers (CD44 and integrins). Several drugs have been identified by screening or other observations (salinomycin, metformin, tesmilifene, sulforaphane, curcumin, piperine and others). Some of these drugs are at preclinical or early clinical phases of development, and it remains to be seen how many will progress to clinical application. This review focuses on some promising new developments in anti-CSC drug therapy.     

间充质干细胞来源的外泌体抑制乳腺癌细胞生长的研究

摘要： 目的 研究脐带间充质干细胞来源的外泌体 （MSCs-Exo） 对乳腺癌细胞生长的影响。方法 利用生物发光成像技术的双报告基因 （萤火虫荧光素酶-绿色荧光蛋白, Fluc-GFP） 载体, 通过慢病毒转染构建人乳腺癌MDA- MB-231细胞系 （231-Fluc-GFP）, 以便在体内可以对细胞进行实时监测。分别采用MSCs-Exo （MSCs-Exo组） 和PBS （对照组） 处理细胞, 体外实验对2组细胞进行形态学观察、 增殖、 存活、 STAT3及其下游基因表达的检测; 通过皮下注射2组细胞建立裸鼠体内乳腺癌模型, 对不同处理条件下的细胞成瘤情况进行分析。结果 体外实验结果显示 MSCs-Exo处理后乳腺癌MDA-MB-231细胞增殖受到了抑制, 在处理第3天时2组细胞数差异有统计学意义 （P＜ 0.05）; 处理后细胞存活率降低 （P＜0.01）; 外泌体处理组STAT3及其下游基因C-MYC, BCL-XL, NANOG, OCT4, SOX2 表达下降。体内实验结果显示MSCs-Exo处理组肿瘤细胞在体内的生长受到抑制。结论 脐带间充质干细胞来源的外泌体抑制乳腺癌细胞的生长。     

Detection of trastuzumab efficacy using 1H MRI ex vivo of breast cancer cells

This study is aimed on Magnetic resonance imaging (MRI) modalities for monitoring Herceptin (trastuzumab) efficacy in breast cancer cells ex vivo. The efficacy profile of trastuzumab (0.010?μg/ml) was examined using T₂ relaxivity measurements prior to and after 24, 48, and 72?h treatment. The untreated MCF-7 cells were considered as a control. MRI results show early tumor response to treatment while comparing pre- and post-treatment T₂. The changes of T₂ MRI correspond to tumor growth inhibition. The study shows that MRI can be used for the non-invasive monitoring of cancer cells’ death caused by immuno-targeting in preclinical testing of efficacy and treatment regimens.     

Activation of the aryl hydrocarbon receptor by TCDD inhibits mammary tumor metastasis in a syngeneic mouse model of breast cancer

Treatment with aryl hydrocarbon receptor (AhR) agonists can slow or reverse the growth of primary mammary tumors in rodents, which has fostered interest in developing selective AhR modulators for treatment of breast cancer. However, the major goal of breast cancer therapy is to inhibit metastasis, the primary cause of mortality in women with this disease. Studies conducted using breast cancer cell lines have demonstrated that AhR agonists suppress proliferation, invasiveness, and colony formation in vitro; however, further exploration using in vivo models of metastasis is warranted. To test the effect of AhR activation on metastasis, 4T1.2 mammary tumor cells were injected into the mammary gland fat pad of syngeneic Balb/c mice treated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Primary tumor growth was monitored for 4 weeks, at which time metastasis was determined. TCDD treatment suppressed metastasis by approximately 50%, as measured both in the lung and in mammary glands at sites distant from the primary tumor. Primary tumor growth was not suppressed by TCDD exposure nor was proliferation of 4T1.2 cells affected by TCDD treatment in vitro. Taken together, these results suggest that the protective effect of AhR activation was selective for the metastatic process and not simply the result of a direct decrease in tumor cell proliferation or survival at the primary site. These observations in immunologically intact animals warrant further investigation into the mechanism of the protective effects of AhR activation and support the promise for use of AhR modulators to treat breast cancer.     

SLT-VEGF Reduces Lung Metastases, Decreases Tumor Recurrence, and Improves Survival in an Orthotopic Melanoma Model

SLT-VEGF is a recombinant cytotoxin comprised of Shiga-like toxin (SLT) subunit A fused to human vascular endothelial growth factor (VEGF). It is highly cytotoxic to tumor endothelial cells overexpressing VEGF receptor-2 (VEGFR-2/KDR/Flk1) and inhibits the growth of primary tumors in subcutaneous models of breast and prostate cancer and inhibits metastatic dissemination in orthotopic models of pancreatic cancer. We examined the efficacy of SLT-VEGF in limiting tumor growth and metastasis in an orthotopic melanoma model, using NCR athymic nude mice inoculated with highly metastatic Line IV Cl 1 cultured human melanoma cells. Twice weekly injections of SLT-VEGF were started when tumors became palpable at one week after intradermal injection of 1 × 10(6) cells/mouse. Despite selective depletion of VEGFR-2 overexpressing endothelial cells from the tumor vasculature, SLT-VEGF treatment did not affect tumor growth. However, after primary tumors were removed, continued SLT-VEGF treatment led to fewer tumor recurrences (p = 0.007), reduced the incidence of lung metastasis (p = 0.038), and improved survival (p = 0.002). These results suggest that SLT-VEGF is effective at the very early stages of tumor development, when selective killing of VEGFR-2 overexpressing endothelial cells can still prevent further progression. We hypothesize that SLT-VEGF could be a promising adjuvant therapy to inhibit or prevent outgrowth of metastatic foci after excision of aggressive primary melanoma lesions.     

Synthesis and reactivity of a potential carcinogenic metabolite of tamoxifen: 3,4-dihydroxytamoxifen-o-quinone

Although tamoxifen is approved for the treatment of hormone-dependent breast cancer as well as for the prevention of breast cancer in high-risk women, several studies in animal models have shown that tamoxifen is heptocarcinogenic, and in humans, tamoxifen has been associated with an increased risk of endometrial cancer. One potential mechanism of tamoxifen carcinogenesis could involve metabolism of tamoxifen to 3,4-dihydroxytamoxifen followed by oxidation to a highly reactive o-quinone which has the potential to alkylate and/or oxidize cellular macromolecules in vivo. In the study presented here, we synthesized the 3,4-dihydroxytamoxifen, prepared its o-quinone chemically and enzymatically, and studied the reactivity of the o-quinone with GSH and deoxynucleosides. The E (trans) and Z (cis) isomers of 3,4-dihydroxytamoxifen were synthesized using a concise synthetic pathway (four steps). This approach is based on the McMurry reaction between the key 4-(2-chloroethoxy)-3,4-methylenedioxybenzophenone and propiophenone, followed by selective removal of the methylenedioxy ring of (E, Z)-1-[4-[2-(N,N-dimethylamino)ethoxy]phenyl]-1-(3, 4-methylenedioxyphenyl)-2-phenyl-1-butene with BCl(3). Oxidation of 3,4-dihydroxytamoxifen by activated silver oxide or tyrosinase gave 3,4-dihydroxytamoxifen-o-quinone as a mixture of E and Z isomers. The resulting o-quinone has a half-life of approximately 80 min under physiological conditions. Reaction of the o-quinone with GSH gave two di-GSH conjugates and three mono GSH conjugates. Incubation of 3,4-dihydroxytamoxifen with GSH in the presence of microsomal P450 gave the same GSH conjugates which were also detected in incubations with human breast cancer cells (MCF-7). Reaction of 3, 4-dihydroxytamoxifen-o-quinone with deoxynucleosides gave only thymidine and deoxyguanosine adducts; neither deoxyadenosine nor deoxycytosine adducts were detected. Preliminary studies conducted with human breast cancer cell lines showed that 3, 4-dihydroxytamoxifen exhibited cytotoxic potency similar to that of 4-hydroxytamoxifen and tamoxifen in an estrogen receptor negative (ER(-)) cell line (MDA-MB-231); however, in the ER(+) cell line (MCF-7), the catechol metabolite was about half as toxic as the other two compounds. Finally, in the presence of microsomes and GSH, 4-hydroxytamoxifen gave predominantly quinone methide GSH conjugates as reported in the previous paper in this issue [Fan, P. W., et al. (2000) Chem. Res. Toxicol. 13, XX-XX]. However, in the presence of tyrosinase and GSH, 4-hydroxytamoxifen was primarily converted to o-quinone GSH conjugates. These results suggest that the catechol metabolite of tamoxifen has the potential to cause cytotoxicity in vivo through formation of 3,4-dihydroxytamoxifen-o-quinone.     

meso-1,2-bis(2,6-dichloro-4-hydroxyphenyl) ethylenediamine]dichloroplatinum(II), a compound with a specific activity on hormone-sensitive breast cancers--evidence for a diethylstilbestrol-like mode of action

[meso-1,2-Bis(2,6-dichloro-4-hydroxyphenyl)ethylenediamine]- dichloroplatinum(II) (meso-1-PtCl2), an estrogenic and cytotoxic platinum complex, shows activity against ER+ but not against ER- breast cancers in vivo (ER: estrogen receptor; ER+ and ER- indicate the presence or absence of the ER). To clarify whether its estrogenic or its cytotoxic potency or both properties are the cause of this specific inhibitory effect, we tested meso-1-PtCl2 comparatively in vivo on an ER+ and an ER- murine breast cancer (MXT-M-3.2 MC and MXT-M-3.2(ovex) MC, respectively), and in vitro on two cell lines derived from the former in vivo models (MXT+ and MXT-, respectively). The estrogens diethylstilbestrol (DES) and the ligand of meso-1-PtCl2 (meso-1), responsible for the hormonal effect of meso-1-PtCl2, and the cytotoxic drug cisplatin (cDDP) were used as comparative substances. Meso-1-PtCl2. DES and cDDP showed a strong and comparable activity on the ER+ MXT-M-3.2 MC in vivo, meso-1 being somewhat less inhibitory. In experiments on the murine, ER- MXT-M-3.2(ovex) MC only cDDP caused a marked inhibitory effect. The other compounds were inactive or only marginally active. In accordance with the in vivo results cDDP was also very active on the MXT+ and MXT- breast cancer cell line. In contrast to this meso-1-PtCl2, meso-1, and DES proved to be only weakly active or inactive on both cell lines. From these results it can be concluded that there is only little if any contribution of the cytotoxic PtCl2 moiety of meso-1-PtCl2 to the anti-breast cancer activity in vivo. On the ER+ MXT-M-3.2 MC transplanted into ovariectomized mice meso-1-PtCl2 yielded a biphasic dose activity curve, i.e. an increase of the tumor growth at low doses followed by a decrease at high doses, identical with those of the estrogens DES and meso-1. These results indicate that meso-1-PtCl2 inhibits ER+ breast cancers by its estrogenicity in the same manner as meso-1 and DES. The complex mechanism of anti-breast cancer active estrogens involves presumably the endocrine and/or the immune system. Its investigation is the subject of further studies.     

Trastuzumab emtansine (T-DM1) for HER2-positive breast cancer

Abstract

Background:

Trastuzumab emtansine (T-DM1), a novel drug developed for the treatment of HER2-positive breast cancer, is a human epidermal growth factor receptor (HER2) targeted antibody drug conjugate, composed of trastuzumab, a stable thioether linker, and the potent cytotoxic agent DM1 (derivative of maytansine). It has been shown that, in preclinical studies, it has anti-tumor activity in trastuzumab refractory cancer cells. In this review, we aim to show the clinical data about trastuzumab-DM1 (T-DM1) therapy and to discuss the therapy advantages for the management of patients with HER2-positive breast cancer.     

Synthesis and antiproliferative activity in vitro of new propargyl thioquinolines

The series of new 3,4-disubstituted thioquinolines which possess one or two O, S, Se-propargyl groups has been synthesized on the basis of the reaction of thioquinanthrene with alkoxides. All the compounds obtained were tested for their antiproliferative activity in vitro against the cells of three human cancer cell lines: SW707 (colon cancer), T47D (breast cancer), and HCV29T (bladder cancer). Two compounds, 4-(3-hydroxypropoxy)-3'-propargylthio-3,4'-diquinolinyl sulfide (3) and 3-methylthio-4-propargylselenoquinoline (13) exhibited significant cytostatic activity (ID50 < 4 micrograms/ml) against the cells of all the human cancer lines used and are good candidates for further anticancer activity studies in vitro using a broad panel of human and murine cell lines and for in vivo preclinical screening in different mouse transplantable tumor models.     

Acute phorbol ester treatment inhibits thapsigargin-induced cell death in porcine aortic smooth muscle cells

Both mycelium and fruiting body of Antrodia camphorate, a traditional medicinal fungus of the family Polyporaceae in Taiwan, have been suggested to possess multiple biological functions. However, there is little information on the anticancer components and actions of mycelium of Antrodia camphorate. In the present study, the anticancer potential of synthesized maleimide derivatives, which have been isolated from mycelium of Antrodia camphorate, is examined. Comparing the cytotoxicity of two synthesized maleimide derivatives in four human cancer cell lines, camphorataimide B displayed potent efficacy. Then we investigated the impact of camphorataimide B on cell survival and cell cycle progression in vitro, and tumor growth in vivo in MDA-MB-231 breast cancer cells. Camphorataimide B decreased the cell viability and foci formation of MDA-MB-231 breast cancer cells. Further, camphorataimide B triggered apoptosis and blocked cell cycle progression of MDA-MB-231 breast cancer cells. Using immunoblotting analysis, camphorataimide B decrease the expression of cyclin-A and cyclin-B1. Moreover, we demonstrated for the first time that camphorataimide B inhibited cyclooxygenase-2 (COX-2) activity and protein expression in MDA-MB-231 cells. In nude mice study, camphorataimide B administration retarded the xenograft tumor growth of MDA-MB-231 cells. By immunohistochemical analysis, camphorataimide B decreased the expression of Ki-67 in xenograft tumor in vivo. It implied that camphorataimide B blocked cell cycle progression. Consistent with the cell culture investigation, camphorataimide B also reduced the expression of cyclin-A, cyclin-B1 and COX-2 in xenograft tumor. Thus, camphorataimide B may play a crucial role in prevention and therapy of malignant breast cancer.     

CD70 as a therapeutic target in human malignancies

Background: Expression of CD70, a member of the tumor necrosis factor superfamily, is restricted to activated T and B lymphocytes and mature dendritic cells. CD70 has also been detected on hematological tumors and on carcinomas. The restricted expression pattern of CD70 in normal tissues and its widespread expression in various malignancies makes it an attractive target for antibody-based therapeutics. Investigations to exploit CD70 as a cancer target have lead to the identification of potential antibody-based clinical candidates. Anti-CD70 antibodies for therapeutic use have been developed and used to validate CD70 as a target for cancers. Antibodies are also used as a vehicle to deliver potent cytotoxic drugs to target CD70⁺malignant cells. Both unconjugated antibodies and antibody–drug conjugates targeting CD70 have been tested in animal models of human cancers. Objective: To describe the expression of CD70 in cancer cells and the development of antiboy-based therapies against CD70. Methods: A review of the available literature. Results/conclusions: Humanized anti-CD70 antibodies have shown significant antitumor activity in preclinical xenograft models of cancer. Additionally, anti-CD70 antibody-drug conjugates exhibit potent antitumor activity in solid tumor xenograft models, confirming increased therapeutic efficacy through cytotoxic drug delivery. Thus, preclinical animal models have provided strong evidence that targeting CD70 either with unconjugated antibodies or with antibody-drug conjugates represents a promising approach to treat human malignancies.     

Antiphospholipid autoantibodies promote breast tumor progression by tissue factor-dependent vascular normalization

OBJECTIVE To identify antiphospholipid autoantibodies(a PLs) as one of patientcharacteristics in breast tumor progression and explore the underlying mechanism. METHODS We examined the circulating a PLs levels in breast cancer patients. We determined the effects of human a PLs on tumor progression in multiple in vivo models of breast cancer and evaluatedthe histopathological characteristics by hemotoxylin and eosin staining and immunohistochemistry staining. Knockdown and neutralization studies were incorporated to confirm the effects of a PLs. RESULTS We observed that high levels of circulating a PLs among breast cancer patients is specifically associated with invasive-stage tumors. a PL Ig G from patients' serum rapidly stimulated tumor angiogenesis and consequent tumor progression, specifically in slow-growing avascular tumors in breast tumor mouse models. a PLs elicited leukocytic infiltration in the tumor site. Tumor cells treated with a PL Ig G expressed multiple proangiogenic genes, including vascular endothelial growth factor, tissue factor(TF), and colony-stimulating factor 1. Knockdown and neutralization studies demonstrated that the effects of a PLs on tumor angiogenesis and growth were dependent on tumor cel derived TF. Tumorderived TF induced by Apl was essential for vascular normalization by improving pericyte coverage of tumor microvessels mediated by chemokine ligand 2. CONCLUSION Antiphospholipid autoantibodies action as a potential patient-specific endogenous factor promoting the transition of indolent tumors to an angiogenic malignant state through a TF-mediated pathogenic mechanism.     

Ganoderic acids suppress growth and angiogenesis by modulating the NF-kappaB signaling pathway in breast cancer cells

It has been demonstrated that ganoderma acids suppress growth, angiogenesis and invasiveness of highly invasive and metastatic breast cancer cells in vitro and vivo. However, the mechanism of action of ganoderma acids in breast cancer remains unknown. In the present study, we looked into the effect of ganoderic acid Me (GA-Me) on cellular phenotypes and tumor growth in the MDA-MB-231 breast cancer cell line. The results indicated the GA-Me inhibited nuclear factor kappaB (NF-κB) activity at 24 h in MDA-MB-231 cells. When MDAMB- 231 cells were stimulated with tumor necrosis factor-alpha (TNF-α), the inhibitory effects of GA-Me were still maintained. We demonstrated that GA-Me inhibited proliferation and invasion and induced apoptosis in MDA-MB-231 cells via suppressing the NF-κB activity. However, GA-Me did not inhibit the phosphorylation and degradation of IkappaB-α (IkB-α). GA-Me down-regulated the expression of various NF-κB-regulated genes including genes involved in cell proliferation (c-Myc and cyclin D1), anti-apoptosis (Bcl-2), invasion (MMP-9) and angiogenesis (VEGF, interleukin (IL)-6 and -8). I.P. administration of GA-Me inhibited tumor growth of MDA-MB-231 cells in vivo. Our results demonstrated that GA-Me inhibited proliferation, angiogenesis, invasion and induced apoptosis in MDA-MB-231 cells via suppressing NF-κB activity and the expression profile of its downstream genes. These findings provide evidence for a novel role of GA-Me in the prevention and treatment of breast cancer by its ability to modulate the NF-κB signaling pathway.     

Matrine exerts an anti-tumor effect via regulating HN1 in triple breast cancer both in vitro and in vivo

The treatment of triple-negative breast cancer (TNBC) cannot meet medical needs, and it is urgent to find new drugs for intervention. This study aimed to investigate the anti-tumor effect of matrine on the proliferation and apoptosis of TNBC cells based on HN1 regulation in vitro and in vivo. TNBC cell lines (MDA-MB-453 and HCC-1806) were treated with varying concentrations of matrine (0, 1.0, 2.0, 3.0, 4.0, and 5.0 mM). CCK-8, colony formation assay, transwell assay, and flow cytometry assay were employed to detect proliferation, clone formation, invasion, and apoptosis of TNBC cells. Western blot analysis was applied to detect the protein expression of apoptosis HN1. The effects of matrine on tumor growth, protein expression of HN1, and apoptosis in vivo were validated by xenograft tumor models and histology. It was found that matrine inhibited proliferation, colony formation, and invasion and promoted apoptosis of TNBC cells in vitro. HN1 expression was suppressed by matrine. HN1 overexpression perceptibly reversed the above-mentioned additive effect in vitro. In vivo experiments found that matrine inhibited tumor growth and the expression of HN1 protein but promoted the protein expression of Cleared-Caspase-3. Above all, this study demonstrated that matrine inhibited proliferation and promoted apoptosis of TNBC cells via suppressing HN1 expression. Targeting HN1 by matrine may provide new insights into the therapeutic management of patients with TNBC.     

Betulinic acid delivered in liposomes reduces growth of human lung and colon cancers in mice without causing systemic toxicity

Betulinic acid (BetA) is a plant-derived pentacyclic triterpenoid with potent anticancer capacity that targets the mitochondrial pathway of apoptosis. BetA has a broad efficacy in vitro against prevalent cancer types, including lung, colorectal, prostate, cervix and breast cancer, melanomas, neuroblastomas, and leukemias. The cytotoxic effects of the compound against healthy cells are minimal, rendering BetA a promising potential anticancer drug. However, because of the weak hydrosolubility of BetA, it has been difficult to study its efficacy in vivo and a pharmaceutical formulation is not yet available. We report the development of a liposome formulation of BetA and show its successful application in mice. Large liposomes, assembled without cholesterol to reduce their rigidity, efficiently incorporated BetA. Nude mice xenografted with human colon and lung cancer tumors were treated intravenously with the BetA-containing liposomes. Tumor growth was reduced to more than 50% compared with the control treatment, leading to an enhanced survival of the mice. Oral administration of the liposomal formulation of BetA also slowed tumor growth. Any signs of systemic toxicity caused by BetA treatment were absent. Thus, liposomes are an efficient formulation vehicle for BetA, enabling its preclinical development as a nontoxic compound for the treatment of cancers.