Chemotherapy in vivo against M109 murine lung carcinoma with cytochalasin B by localized, systemic, and liposomal administration

Integrated Mini-Pillar Platform for Wireless Real-Time Cell Monitoring

Cell culture as the cornerstone of biotechnology remains a labor-intensive process requiring continuous manual oversight and substantial time investment. In this work, we propose an integrated mini-pillar platform for in situ monitoring of multiple cellular metabolism processes, which achieves media anchoring and cell culture through an arrayed mini-pillar chip. The assembly of polyaniline (PANI)/dendritic gold-modified microelectrode biosensors exhibits high sensitivity (63.55 mV/pH) and excellent interference resistance, enabling real-time acquisition of biosensing signals. We successfully employed such integrated devices to real-time measuring pH variations in multiple cells and real-time monitoring of cell metabolism under drug interventions and to facilitate in situ assisted cultivation of 3-dimensional (3D) cell spheroids. This mini-pillar array-based cell culture platform exhibits excellent biosensing sensitivity and real-time monitoring capability, offering considerable potential for the advancement of biotechnology and medical drug development.

Cytochalasin Q exerts anti-melanoma effect by inhibiting creatine kinase B

Due to the pivotal role of microfilament in cancer cells, targeting microfilaments with cytochalasins is considered a promising anticancer strategy. Here, we obtained cytochalasin Q (CQ) from Xylaria sp. DO1801, the endophytic fungi from the root of plant Damnacanthus officinarum, and discovered its anti-melanoma activity in vivo and in vitro attributing to microfilament depolymerization. Mechanistically, CQ directly bound to and inactivated creatine kinase B (CKB), an enzyme phosphorylating creatine to phosphocreatine (PCr) and regenerating ATP to cope with high energy demand, and then inhibited the creatine metabolism as well as cytosolic glycolysis in melanoma cells. Preloading PCr recovered ATP generation, reversed microfilament depolymerization and blunted anti-melanoma efficacy of CQ. Knockdown of CKB resulted in reduced ATP level, perturbed microfilament, inhibited proliferation and induced apoptosis, and manifested lower sensitivity to CQ. Further, we found that either CQ or CKB depletion suppressed the PI3K/AKT/FoxO1 pathway, whereas 740Y-P, a PI3K agonist, elevated protein expression of CKB suppressed by CQ. Taken together, our study highlights the significant anti-melanoma effect and proposes a PI3K/AKT/FoxO1/ CKB feedback circuit for the activity of CQ, opening new opportunities for current chemotherapy.

Tropism of Extracellular Vesicles and Cell-Derived Nanovesicles to Normal and Cancer Cells: New Perspectives in Tumor-Targeted Nucleic Acid Delivery

The main advantage of extracellular vesicles (EVs) as a drug carrier system is their low immunogenicity and internalization by mammalian cells. EVs are often considered a cell-specific delivery system, but the production of preparative amounts of EVs for therapeutic applications is challenging due to their laborious isolation and purification procedures. Alternatively, mimetic vesicles prepared from the cellular plasma membrane can be used in the same way as natural EVs. For example, a cytoskeleton-destabilizing agent, such as cytochalasin B, allows the preparation of membrane vesicles by a series of centrifugations. Here, we prepared cytochalasin-B-inducible nanovesicles (CINVs) of various cellular origins and studied their tropism in different mammalian cells. We observed that CINVs derived from human endometrial mesenchymal stem cells exhibited an enhanced affinity to epithelial cancer cells compared to myeloid, lymphoid or neuroblastoma cancer cells. The dendritic cell-derived CINVs were taken up by all studied cell lines with a similar efficiency that differed from the behavior of DC-derived EVs. The ability of cancer cells to internalize CINVs was mainly determined by the properties of recipient cells, and the cellular origin of CINVs was less important. In addition, receptor-mediated interactions were shown to be necessary for the efficient uptake of CINVs. We found that CINVs, derived from late apoptotic/necrotic cells (aCINVs) are internalized by in myelogenous (K562) 10-fold more efficiently than CINVs, and interact much less efficiently with melanocytic (B16) or epithelial (KB-3-1) cancer cells. Finally, we found that CINVs caused a temporal and reversible drop of the rate of cell division, which restored to the level of control cells with a 24 h delay.

Preparation of ROS active and photothermal responsive hydroxyapatite nanoplatforms for anticancer therapy

Photothermal responsive nanoplatforms are attracting for photothermal therapy (PTT) of cancer. Herein, we propose a strategy to prepare IR-780 modified hydroxyapatite (HAP) nanorods as photothermic agents (HAP@IR-780). The results demonstrated that the obtained HAP@IR-780 was photothermal responsive under near-infrared laser irradiation the photothermal conversion efficiency was 69.3%, and it remained photostability after 4 cycles of irradiation. This advantage overcomes the optical instability of IR780. MTT and cellular uptake research proved that HAP@IR-780 was biocompatible in appropriate concentration range (0-20 μg/mL) without laser irradiation. Concentration-dependent internalization and reactive oxygen species (ROS) related apoptosis of HAP@IR-780 for MCF-7 cells were observed. Animal experiments showed that the gathered HAP@IR-780 at the tumor site reached a photothermal responsive temperature up to 57.9 °C, which could almost ablate the tumor with volumes as large as 1500 mm³. In general, our photothermal material has good photothermal conversion characteristics, and may have the least safety problems while showing excellent therapeutic effects. Therefore, HAP@IR-780 has a brilliant prospect in the field of tumor photothermal therapy.

Comparative genome analysis proposes three new Aureobasidium species isolated from grape juice

Aureobasidium pullulans is the most abundant and ubiquitous species within the genus and is also considered a core component of the grape juice microflora. So far, a small number of other Aureobasidium species have been reported, that in contrast to A. pullulans, appear far more constrained to specific habitats. It is unknown whether grape juice is a reservoir of novel Aureobasidium species, overlooked in the course of conventional morphological and meta-barcoding analyses. In this study, eight isolates from grape juice taxonomically classified as Aureobasidium through ITS sequencing were subjected to whole-genome phylogenetic, synteny and nucleotide identity analyses, which revealed three isolates to likely represent newly discovered Aureobasidium species. Analyses of ITS and metagenomic sequencing datasets show that these species can be present in grape juice samples from different locations and vintages. Functional annotation revealed the Aureobasidium isolates possess the genetic potential to support growth on the surface of plants and grapes. However, the loss of several genes associated with tolerance to diverse environmental stresses suggest a more constrained ecological range than A. pullulans.

Antiplasmodial and Cytotoxic Cytochalasins from an Endophytic Fungus, Nemania sp. UM10M, Isolated from a Diseased Torreya taxifolia Leaf

Bioassay-guided fractionation of an EtOAc extract of the broth of the endophytic fungus Nemania sp. UM10M (Xylariaceae) isolated from a diseased Torreya taxifolia leaf afforded three known cytochalasins, 19,20-epoxycytochalasins C (1) and D (2), and 18-deoxy-19,20-epoxy-cytochalasin C (3). All three compounds showed potent in vitro antiplasmodial activity and phytotoxicity with no cytotoxicity to Vero cells. These compounds exhibited moderate to weak cytotoxicity to some of the cell lines of a panel of solid tumor (SK-MEL, KB, BT-549, and SK-OV-3) and kidney epithelial cells (LLC-PK₁₁). Evaluation of in vivo antimalarial activity of 19,20-epoxycytochalasin C (1) in a mouse model at 100 mg/kg dose showed that this compound had weak suppressive antiplasmodial activity and was toxic to animals.

The biosynthesis of cytochalasans

This highlight summarises the recent advances in elucidating and engineering the biosynthesis of cytochalasan natural products.

Recent Advances in the Development of Antineoplastic Agents Derived from Natural Products

Through years of evolutionary selection pressures, organisms have developed potent toxins that coincidentally have marked antineoplastic activity. These natural products have been vital for the development of multiagent treatment regimens currently employed in cancer chemotherapy, and are used in the treatment of a variety of malignancies. Therefore, this review catalogs recent advances in natural product-based drug discovery via the examination of mechanisms of action and available clinical data to highlight the utility of these novel compounds in the burgeoning age of precision medicine. The review also highlights the recent development of antibody-drug conjugates and other immunotoxins, which are capable of delivering highly cytotoxic agents previously deemed too toxic to elicit therapeutic benefit preferentially to neoplastic cells. Finally, the review examines natural products not currently used in the clinic that have novel mechanisms of action, and may serve to supplement current chemotherapeutic protocols.

Actin-binding doliculide causes premature senescence in p53 wild type cells

Addressing the actin cytoskeleton as future anticancer target can be an innovative chemotherapeutic approach to combat malignancies. Doliculide is a potent stabilizer of actin filaments and can be used as tool and therapeutic lead in cancer research. Though a variety of molecules are known to bind to actin and lead to either its over- or depolymerization little is known about the pharmacological consequences of these effects within the cancer cell. In this work we used p53 wild-type cells to dissect the reaction of these cells towards subtoxic doses of doliculide. We could show that doliculide leads to a transient change in actin cytoskeleton dynamics that are reversible. The cells react towards the treatment with the induction of premature senescence, an established anti-cancer mechanism, in concentrations that are not cytotoxic. Furthermore, we investigated the signaling pathways that are involved in the induction and maintenance of senescence by a pathway directed mRNA PCR-array. This analysis revealed that under doliculide treatment up to 13% of senescence related genes are altered. Taken together, our data provide evidence for an antitumoral potential of actin binding agents in p53 wild type cells and brings the strategy of targeting the actin cytoskeleton closer to clinical application.

Preparation, In Vivo Administration, Dose-Limiting Toxicities, and Antineoplastic Activity of Cytochalasin B

An effective and inexpensive protocol for producing cytochalasins A and B is being disclosed to propose a viable method by which to examine the in vivo antineoplastic activity of these congeners in preclinical tumor-bearing mammalian models. In addition, we determine the maximum tolerated doses of cytochalasin B using multiple routes and formulations, characterize the tissue distribution of intravenous bolus cytochalasin B, and assess the in vivo antineoplastic activity of cytochalasin B in comparison in doxorubicin in Balb/c mice challenged intradermally with M109 murine lung carcinoma. We also examine the effects of cytochalasin B against several other murine neoplastic cell lines (Lewis lung, LA4, B16F10, and M5076). Finally, we examine a potential mechanism of the antimetastatic activity of cytochalasin B by observing the effects of the agent on the secretion of N-acetylglucosaminidase (GlcNACase) by B16BL6 and B16F10 murine melanomas in vitro. The results of the study can be summarized as follows: 1) Cytochalasin B can be safely administered intravenously, intraperitoneally, and subcutaneously in murine models, with the maximum tolerated dose of all routes of administration being increased by liposome encapsulation. 2) Cytochalasin B can significantly inhibit the growth of tumors in mice challenged with M109, Lewis lung, LA4, B16F10, or M5076, producing long-term survival against lung carcinomas and adenocarcinomas (M109, Lewis lung, and LA4) and B16F10 melanoma, but not M5076 sarcoma. These effects were comparable to intraperitoneally administered doxorubicin. 4) Low concentrations of cytochalasin B inhibit the secretion of GlcNACase, indicating that cytochalasin B may inhibit metastatic progression by mechanisms not directly associated with its influence on cell adhesion and motility.

The actin depolymerizing factor (ADF)/cofilin signaling pathway and DNA damage responses in cancer

The actin depolymerizing factor (ADF)/cofilin protein family is essential for actin dynamics, cell division, chemotaxis and tumor metastasis. Cofilin-1 (CFL-1) is a primary non-muscle isoform of the ADF/cofilin protein family accelerating the actin filamental turnover in vitro and in vivo. In response to environmental stimulation, CFL-1 enters the nucleus to regulate the actin dynamics. Although the purpose of this cytoplasm-nucleus transition remains unclear, it is speculated that the interaction between CFL-1 and DNA may influence various biological responses, including DNA damage repair. In this review, we will discuss the possible involvement of CFL-1 in DNA damage responses (DDR) induced by ionizing radiation (IR), and the implications for cancer radiotherapy.

Chemotherapy with cytochalasin congeners in vitro and in vivo against murine models

Background Despite inherent differences between the cytoskeletal networks of malignant and normal cells, and the clinical antineoplastic activity of microtubule-directed agents, there has yet to be a microfilament-directed agent approved for clinical use. One of the most studied microfilament-directed agents has been cytochalasin B, a mycogenic toxin known to disrupt the formation of actin polymers. Therefore, this study sought to expand on our previous work with the microfilament-directed agent, along with other less studied cytochalasin congeners. Materials and Methods We determined whether cytochalasin B exerted significant cytotoxic effects in vitro on adherent M109 lung carcinoma and B16BL6 and B16F10 murine melanomas, or on suspension P388/ADR murine leukemia cells. We also examined whether cytochalasin B, its reduced congener 21, 22-dihydrocytochalasin B (DiHCB), or cytochalasin D could synergize with doxorubicin (ADR) against ADR-resistant P388/ADR leukemia cells, and produce significant cytotoxicity in vitro. For in vivo characterization, cytochalasins B and D were administered intraperitoneally (i.p.) to Balb/c mice challenged with drug sensitive P388-S or multidrug resistant P388/ADR leukemias. Results Cytochalasin B demonstrated higher cytotoxicity against adherent lung carcinoma and melanoma cells than against suspension P388/ADR leukemia cells, as assessed by comparative effects on cell growth, and IC₅₀ and IC₈₀ values. Isobolographic analysis indicated that both cytochalasin B and DiHCB demonstrate considerable drug synergy with ADR against ADR-resistant P388/ADR leukemia, while cytochalasin D exhibits only additivity with ADR against the same cell line. In vivo, cytochalasins B and D substantially increased the life expectancy of mice challenged with P388/S and P388/ADR leukemias, and in some cases, produced long-term survival. Conclusion Taken together, it appears that cytochalasins have unique antineoplastic activity that could potentiate a novel class of chemotherapeutic agents.