Reversal effects of hyaluronan oligosaccharides on adriamycin resistance of K562/A02 cells

Hyaluronic acid oligosaccharide-modified zeolitic imidazolate framework-8 nanoparticles loaded with oxaliplatin as a targeted drug-delivery system for colorectal cancer therapy

Aim: Exploring a nanoscale targeted drug-delivery system (DDS) for oxaliplatin (Oxa) to improve its therapeutic effect in colorectal cancer. Materials & methods: Nanoparticles were prepared using zeolitic imidazole framework-8 (ZIF-8) modified by hyaluronic acid oligosaccharide (oHA) as an Oxa carrier (oHA@ZIF-8@Oxa). After multiple characterizations, the therapeutic efficacy of the DDS was evaluated by cytotoxicity testing and a nude mouse tumor transplantation experiment in vivo. Results: The results of characterization showed the DDS was homogeneous in morphology and uniform in dispersion. The drug loading of Oxa was 11.82% and the encapsulation efficiency was 90.8%. The cytotoxicity test and in vivo experiments showed that oHA@ZIF-8@Oxa had a more significant anticolorectal cancer effect than free Oxa. Conclusion: This work offers a promising potential DDS for enhancing the anticolorectal cancer effect of Oxa.

The ability of hyaluronan fragments to reverse the resistance of C6 rat glioma cell line to temozolomide and carmustine

Aim of the study

Hyaluronan (HA) is an extracellular matrix (ECM) polymer that may contribute to the emergence of anti-cancer drug resistance. Attempts to reverse drug resistance using small hyaluronan oligomers (oHA) are being made. The initial reports suggest that the oHA fraction may effectively reverse anti-cancer drug resistance in glioma models. However, the reversal effects of oHA of defined molecular length on glioma cells have not been investigated yet. In this study, we examined HA fragments containing 2 disaccharide units (oHA-2), 5 disaccharide units (oHA-5), and 68 kDa hyaluronan polymer (HA-68k) as agents possibly reversing the resistance of a C6 rat glioma cell line to temozolomide (TMZ) and carmustine (BCNU).

Material and methods

A 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) viability assay was used to assess the cytotoxicity of TMZ and BCNU in the presence or absence of the hyaluronan fragments. By comparing viability of the cells, the reversal effects of HA fragments on TMZ and BCNU resistance in C6 glioma cells were assessed.

Results

We found statistically significant decreases in the viability of cells in the presence of TMZ+oHA-5 as compared to TMZ alone (51.2 ±4.5 vs. 74.2 ±5.8, p = 0.0031), BCNU+o-HA5 as compared to BCNU alone (49.3 ±4.4 vs. 65.6 ±5.7, p = 0.0119), and BCNU+HA-68k as compared to BCNU alone (55.2 ±2.3 vs. 65.6 ±5.7, p = 0.0496).

Conclusions

Conclusions: Hyaluronan oligomers of 5 disaccharide units (oHA-5) significantly reversed the resistance of C6 cells to TMZ and BCNU. The results are only preliminary and a more thorough follow-up investigation is required to assess their actual role.

Hyaluronan: towards novel anti-cancer therapeutics

The understanding of the role of hyaluronan in physiology and various pathological conditions has changed since the complex nature of its synthesis, degradation and interactions with diverse binding proteins was revealed. Initially perceived only as an inert component of connective tissue, it is now known to be involved in multiple signaling pathways, including those involved in cancer pathogenesis and progression. Hyaluronan presents a mixture of various length polymer molecules from finely fragmented oligosaccharides, polymers intermediate in size, to huge aggregates of high molecular weight hyaluronan. While large molecules promote tissue integrity and quiescence, the generation of breakdown products enhances signaling transduction, contributing to the pro-oncogenic behavior of cancer cells. Low molecular weight hyaluronan has well-established angiogenic properties, while the smallest hyaluronan oligomers may counteract tumor development. These equivocal properties make the role of hyaluronan in cancer biology very complex. This review surveys recent data on hyaluronan biosynthesis, metabolism, and interactions with its binding proteins called hyaladherins (CD44, RHAMM), providing themolecular background underlying its differentiated biological activity. In particular, the article critically presents current ideas on actual role of hyaluronan in cancer. The paper additionally maps a path towards promising novel anti-cancer therapeutics which target hyaluronan metabolic enzymes and hyaladherins, and constitute hyaluronan-based drug delivery systems.

Human leukemic cell lines synthesize hyaluronan to avoid senescence and resist chemotherapy

Hyaluronan (HA) is one of the major components of the extracellular matrix. Several solid tumors produce high levels of HA, which promotes survival and multidrug resistance (MDR). HA oligomers (oHAs) can block HA effects. However, little is known about the role of HA in hematological malignancies. The aim of this work was to determine whether HA or its oligomers can modulate the proliferation of leukemia cells as well as their effect on MDR. Receptors and signaling pathways involved were also analyzed. For this purpose, the human leukemic cell lines K562 and Kv562, which are sensitive and resistant to Vincristine (VCR), respectively, were used. We demonstrated that HA induced cell proliferation in both cell lines. On K562 cells, this effect was mediated by cluster differentiation 44 (CD44) and activation of both phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) and mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) pathways, whereas on Kv562 cells, the effect was mediated by receptor for hyaluronan-mediated motility (RHAMM) and PI3K/Akt activation. The inhibition of HA synthesis by 4-methylumbelliferone (4MU) decreased cell line proliferation and sensitized Kv562 to the effect of VCR through P-glycoprotein (Pgp) inhibition, in both cases with senescence induction. Moreover, oHAs inhibited K562 proliferation mediated by CD44 as well as Akt and ERK down-regulation. Furthermore, oHAs sensitized Kv562 cells to VCR by Pgp inhibition inducing senescence. We postulate that the synthesis of HA would promote leukemia progression mediated by the triggering of the above-mentioned proliferative signals. These findings highlight the potential use of oHAs and 4MU as coadjuvant for drug-resistant leukemia.

Role of versican, hyaluronan and CD44 in ovarian cancer metastasis

There is increasing evidence to suggest that extracellular matrix (ECM) components play an active role in tumor progression and are an important determinant for the growth and progression of solid tumors. Tumor cells interfere with the normal programming of ECM biosynthesis and can extensively modify the structure and composition of the matrix. In ovarian cancer alterations in the extracellular environment are critical for tumor initiation and progression and intra-peritoneal dissemination. ECM molecules including versican and hyaluronan (HA) which interacts with the HA receptor, CD44, have been shown to play critical roles in ovarian cancer metastasis. This review focuses on versican, HA, and CD44 and their potential as therapeutic targets for ovarian cancer.