Microenvironment of mammary fat pads affected the characteristics of the tumors derived from the induced cancer stem cells

Breast cancer is the first common cause of cancer-related death in women worldwide. Since the malignancy and aggressiveness of breast cancer have been correlated with the presence of breast cancer stem cells, the establishment of a disease model with cancer stem cells is required for the development of a novel therapeutic strategy. Here, we aimed to evaluate the availability of cancer stem cell models developed from mouse induced pluripotent stem cells with the conditioned medium of different subtypes of breast cancer cell lines, the hormonal-responsive T47D cell line and the triple-negative breast cancer BT549 cell line, to generate in vivo tumor models. When transplanted into the mammary fat pads of BALB/c nude mice, these two model cells formed malignant tumors exhibiting pronounced histopathological characteristics similar to breast cancers. Serial transplantation of the primary cultured cells into mammary fat pads evoked the same features of breast cancer, while this result was perturbed following subcutaneous transplantation. The tumors formed in the mammary fat pads exhibited immune reactivities to prolactin receptor, progesterone receptor, green florescent protein, Ki67, CD44, estrogen receptor alpha/beta and cytokeratin 8, while all of the tumors and their derived primary cells exhibited immunoreactivity to estrogen receptor alpha/beta and cytokeratin 8. Cancer stem cells can be developed from pluripotent stem cells via the secretory factors of cancer-derived cells with the capacity to inherit tissue specificity. However, cancer stem cells should be plastic enough to be affected by the microenvironment of specific tissues. In summary, we successfully established a breast cancer tumor model using mouse induced pluripotent stem cells developed from normal fibroblasts without genetic manipulation

Chlorotoxin-Fc Fusion Inhibits Release of MMP-2 from Pancreatic Cancer Cells

Chlorotoxin (CTX) is a 36-amino acid peptide derived from Leiurus quinquestriatus (scorpion) venom, which inhibits low-conductance chloride channels in colonic epithelial cells. It has been reported that CTX also binds to matrix metalloproteinase-2 (MMP-2), membrane type-1 MMP, and tissue inhibitor of metalloproteinase-2, as well as CLC-3 chloride ion channels and other proteins. Pancreatic cancer cells require the activation of MMP-2 during invasion and migration. In this study, the fusion protein was generated by joining the CTX peptide to the amino terminus of the human IgG-Fc domain without a hinge domain, the monomeric form of chlorotoxin (M-CTX-Fc). The resulting fusion protein was then used to target pancreatic cancer cells (PANC-1) in vitro. M-CTX-Fc decreased MMP-2 release into the media of PANC-1 cells in a dose-dependent manner. M-CTX-Fc internalization into PANC-1 cells was observed. When the cells were treated with chlorpromazine (CPZ), the internalization of the fusion protein was reduced, implicating a clathrin-dependent internalization mechanism of M-CTX-Fc in PANC-1 cells. Furthermore, M-CTX-Fc clearly exhibited the inhibition of the migration depending on the concentration, but human IgG, as negative control of Fc, was not affected. The M-CTX-Fc may be an effective instrument for targeting pancreatic cancer

In Vitro and In Vivo Antitumor Activity of Indolo[2,3-b] Quinolines, Natural Product Analogs from Neocryptolepine Alkaloid

Neocryptolepine (5-methyl-5H-indolo[2,3-b] quinoline) analogs were synthesized and evaluated in vitro and in vivo for their effect versus Ehrlich ascites carcinoma (EAC). The analogs showed stronger cytotoxic activity against EAC cells than the reference drug. The in vivo evaluation of the target compounds against EAC-induced solid tumor in the female albino Swiss mice revealed a remarkable decrease in the tumor volume (TV) and hepatic lipid peroxidation. A noticeable increase of both superoxide dismutase (SOD) and catalase (CAT) levels was reported (p < 0.001), which set-forth proof of their antioxidant effect. In addition, the in vitro antioxidant activity of the neocryptolepine analogs was screened out using the DPPH method and showed promising activities activity. The histopathological investigations affirmed that the tested analogs have a remarkable curative effect on solid tumors with minimal side-effect on the liver. The study also includes illustrated mechanism of the antitumor activity at the cell level by flow cytometry. The cell cycle analysis showed that the neocryptolepine analogs extensively increase the aggregation of tumor cells in three phases of the cell cycle (G0/G1, S and G2/M) with the emergence of a hypo-diploid DNA content peak (sub-G1) in the cell cycle experiments, which is a clear-cut for the apoptotic cell population. Furthermore, the immunological study manifested a significant elevation in splenic lymphocyte count (p < 0.001) with the elevation of the responsiveness of lymphocytes to phytohemagglutinin (PHA). These results indicate that these naturally-based neocryptolepine alkaloids exhibit marked antitumor activity in vivo and represent an important lead in the development of natural-based anticancer drugs

Synthesis and In Vitro Antiproliferative Activity of 11-Substituted Neocryptolepines with a Branched ω-Aminoalkylamino Chain

Neocryptolepine, which is a kind of tetracyclic indoloquinoline alkaloid, exhibits the inhibition of topoisomerase II and shows antiproliferative activity. The present study describes the synthesis and antiproliferative evaluation of several neocryptolepine analogues carrying a branched, functionalized dibasic side chain at C11. These 2-substituted 5-methyl-indolo[2,3-b]quinoline derivatives were prepared by nucleophilic aromatic substitution (SNAr) of 11-chloroneocryptolepines with appropriate 1,2- and 1,3-diamines. Some of the 11-(ω-aminoalkylamino) derivatives were further transformed into 11-ureido and thioureido analogues. Many of the prepared neocryptolepine derivatives showed submicromolar antiproliferative activity against the human leukemia MV4-11 cell line. Among them, 11-(3-amino-2-hydroxy)propylamino derivatives 2h and 2k were the most cytotoxic with a mean IC50 value of 0.042 μM and 0.057 μM against the MV4-11 cell line, 0.197 μM and 0.1988 μM against the A549 cell line, and 0.138 μM and 0.117 μM against the BALB/3T3 cell line, respectively

In Vitro and In Vivo Antitumor Activity of Indolo[2,3-<i>b</i>] Quinolines, Natural Product Analogs from Neocryptolepine Alkaloid

Neocryptolepine (5-methyl-5H-indolo[2,3-b] quinoline) analogs were synthesized and evaluated in vitro and in vivo for their effect versus Ehrlich ascites carcinoma (EAC). The analogs showed stronger cytotoxic activity against EAC cells than the reference drug. The in vivo evaluation of the target compounds against EAC-induced solid tumor in the female albino Swiss mice revealed a remarkable decrease in the tumor volume (TV) and hepatic lipid peroxidation. A noticeable increase of both superoxide dismutase (SOD) and catalase (CAT) levels was reported (p p < 0.001) with the elevation of the responsiveness of lymphocytes to phytohemagglutinin (PHA). These results indicate that these naturally-based neocryptolepine alkaloids exhibit marked antitumor activity in vivo and represent an important lead in the development of natural-based anticancer drugs

Alpinia zerumbet (Pers.) : Food and Medicinal Plant with Potential In Vitro and In Vivo Anti-Cancer Activities

Background/Aim: Plants play an important role in anti-cancer drug discovery, therefore, the current study aimed to evaluate the biological activity of Alpinia zerumbet (A. zerumbet) flowers. Methods: The phytochemical and biological criteria of A. zerumbet were in vitro investigated as well as in mouse xenograft model. Results: A. zerumbet extracts, specially CH2Cl2 and MeOH extracts, exhibited the highest potent anti-tumor activity against Ehrlich ascites carcinoma (EAC) cells. The most active CH2Cl2 extract was subjected to bioassay-guided fractionation leading to isolatation of the naturally occurring 5,6-dehydrokawain (DK) which was characterized by IR, MS, H-1-NMR and C-13-NMR. A. zerumbet extracts, specially MeOH and CH2Cl2 extracts, exhibited significant inhibitory activity towards tumor volume (TV). Furthermore, A. zerumbet extracts declined the high level of malonaldehyde (MDA) as well as elevated the levels of superoxide dismutase (SOD) and catalase (CAT) in liver tissue homogenate. Moreover, DK showed anti-proliferative action on different human cancer cell lines. The recorded IC50 values against breast carcinoma (MCF-7), liver carcinoma (Hep-G2) and larynx carcinoma cells (HEP-2) were 3.08, 6.8, and 8.7 mu g/mL, respectively. Conclusion: Taken together, these findings open the door for further investigations in order to explore the potential medicinal properties of A. zerumbet

Targeting Glioblastoma Cells Expressing CD44 with Liposomes Encapsulating Doxorubicin and Displaying Chlorotoxin-IgG Fc Fusion Protein

We recently have established a successful xenograft model of human glioblastoma cells by enriching hyaluronic acid-dependent spheroid-forming populations termed U251MG-P1 cells from U251MG cells. Since U251MG-P1 cells have been confirmed to express CD44 along with principal stemness marker genes, OCT3/4, SOX2, KLF4 and Nanog, this CD44 expressing population appeared to majorly consist of undifferentiated cells. Evaluating the sensitivity to anti-cancer agents, we found U251MG-P1 cells were sensitive to doxorubicin with IC50 at 200 nM. Although doxorubicin has serious side-effects, establishment of an efficient therapy targeting undifferentiated glioblastoma cell population is necessary. We previously designed a chlorotoxin peptide fused to human IgG Fc region without hinge sequence (M-CTX-Fc), which exhibited a stronger growth inhibitory effect on the glioblastoma cell line A172 than an original chlorotoxin peptide. Combining these results together, we designed M-CTX-Fc conjugated liposomes encapsulating doxorubicin and used U251MG-P1 cells as the target model in this study. The liposome modified with M-CTX-Fc was designed with a diameter of approximately 100–150 nm and showed high encapsulation efficiency, adequate loading capacity of anticancer drug, enhanced antitumor effects demonstrating increasing uptake into the cells in vitro; M-CTX-Fc-L-Dox shows great promise in its ability to suppress tumor growth in vivo and it could serve as a template for targeted delivery of other therapeutics