In vitro chemosensitivity test of human brain tumors using a three-dimensional organ culture with a collagen gel matrix

Discoidin Domain Receptors, DDR1b and DDR2, Promote Tumour Growth within Collagen but DDR1b Suppresses Experimental Lung Metastasis in HT1080 Xenografts

The Discoidin Domain Receptors (DDRs) constitute a unique set of receptor tyrosine kinases that signal in response to collagen. Using an inducible expression system in human HT1080 fibrosarcoma cells, we investigated the role of DDR1b and DDR2 on primary tumour growth and experimental lung metastases. Neither DDR1b nor DDR2 expression altered tumour growth at the primary site. However, implantation of DDR1b- or DDR2-expressing HT1080 cells with collagen I significantly accelerated tumour growth rate, an effect that could not be observed with collagen I in the absence of DDR induction. Interestingly, DDR1b, but not DDR2, completely hindered the ability of HT1080 cells to form lung colonies after intravenous inoculation, suggesting a differential role for DDR1b in primary tumour growth and lung colonization. Analyses of tumour extracts revealed specific alterations in Hippo pathway core components, as a function of DDR and collagen expression, that were associated with stimulation of tumour growth by DDRs and collagen I. Collectively, these findings identified divergent effects of DDRs on primary tumour growth and experimental lung metastasis in the HT1080 xenograft model and highlight the critical role of fibrillar collagen and DDRs in supporting the growth of tumours thriving within a collagen-rich stroma.

Three dimensional in vitro models of cancer: Bioprinting multilineage glioblastoma models

Three dimensional (3D) bioprinting of multiple cell types within optimised extracellular matrices has the potential to more closely model the 3D environment of human physiology and disease than current alternatives. In this study, we used a multi-nozzle extrusion bioprinter to establish models of glioblastoma made up of cancer and stromal cells printed within matrices comprised of alginate modified with RGDS cell adhesion peptides, hyaluronic acid and collagen-1. Methods were developed using U87MG glioblastoma cells and MM6 monocyte/macrophages, whilst more disease relevant constructs contained glioblastoma stem cells (GSCs), co-printed with glioma associated stromal cells (GASCs) and microglia. Printing parameters were optimised to promote cell-cell interaction, avoiding the 'caging in' of cells due to overly dense cross-linking. Such printing had a negligible effect on cell viability, and cells retained robust metabolic activity and proliferation. Alginate gels allowed the rapid recovery of printed cell protein and RNA, and fluorescent reporters provided analysis of protein kinase activation at the single cell level within printed constructs. GSCs showed more resistance to chemotherapeutic drugs in 3D printed tumour constructs compared to 2D monolayer cultures, reflecting the clinical situation. In summary, a novel 3D bioprinting strategy is developed which allows control over the spatial organisation of tumour constructs for pre-clinical drug sensitivity testing and studies of the tumour microenvironment.

Adult medulloblastoma: multiagent chemotherapy with cisplatinum and etoposide: a single institutional experience

In 1991, a prospective phase II trial was initiated to evaluate the efficacy of treatment for adults with medulloblastoma (MB). After surgery, patients were staged with a neuroradiologic examination of the brain and neuroaxis and by cerebrospinal fluid cytology. All patients received three cycles of upfront cisplatinum (cisplatinum) and etoposide (VP16) chemotherapy followed by cranio-spinal radiation therapy. The current article reports on the long-term results from that trial. After a median follow-up of 14.9 years, among a total of 28 adults with MB, the overall progression-free survival and overall survival (OS) rates at 5 years were 57.6 and 80%, respectively. The median OS for the whole group of patients was 11.3 years. The observed toxicity was mainly hematological, with leukopenia and thrombocytopenia (16% of grades 3 and 4). In summary, in our small series of patients, the role of combination administration of CDDP + VP16 started before the initiation of radiotherapy in reducing recurrences, particularly distant recurrences, remains unclear. To know whether adding chemotherapy to craniospinal radiation in adult therapy increases relapse-free and overall survival, we must await the results of a larger randomized controlled clinical trial.

Collagen gel matrix assay as an in vitro chemosensitivity test for malignant astrocytic tumors

BACKGROUND

The efficacy of individual chemotherapy based on chemosensitivity has scarcely been studied.

METHODS

We examined the chemosensitivites for four anticancer agents - 1-(4-amino-2-methyl-5-pyrimidinyl) methyl-3 (2-chloroethyl)-3-nitrosourea hydrochloride (ACNU), carboplatin, cisplatin, and etoposide - of 43 malignant astrocytic tumors (21 anaplastic astrocytomas and 22 glioblastomas) by using a collagen gel matrix assay, and we also determined the survival periods of the tumor-bearing patients. The chemosensitivity was evaluated in terms of the growth inhibition rate, using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) method.

RESULTS

For the anaplastic astrocytomas, the mean growth inhibitory rate was 33.2% with cisplatin, 37.2% with carboplatin, 28.0% with ACNU, and 24.8% with etoposide. For the glioblastomas, these rates were 36.9%, 42.3%, 23.2%, and 34.8%, respectively. The median overall and progression-free survivals of anaplastic astrocytoma-bearing patients who had undergone chemotherapy with two anticancer drugs, both of which showed significant anticancer activity (growth inhibitory rate >30%) were significantly longer than those of the patients who had been treated with two drugs, one or both of which did not show significant anticancer activity. On the other hand, there was no significant difference in the overall or the progression-free survivals in the two corresponding groups of glioblastoma-bearing patients.

CONCLUSION

The collagen gel matrix assay is clinically useful to determine in vitro chemosensitivity that reflects in vivo chemosensitivity. Individual chemotherapy for malignant astrocytic tumors, based on chemosensitivity data, could contribute to longer survival, particularly in anaplastic astrocytoma-bearing patients.

Matrix metalloproteinases-2, -3, and -9 secreted by explants of benign and malignant lesions of the uterine cervix

Elevated expression of matrix metalloproteinases (MMPs) plays a critical role in extracellular matrix (EM) degradation in tumor development and prognosis of different human carcinomas. In cervical carcinoma (Ce Ca), the role of these proteinases in the biological development of this neoplasm is controversial. In the present study, we compared the secretion of MMP-2, MMP-3 and MMP-9 among 29 benign and premalignant cervical lesions (cervicitis and cervical intraepithelial neoplasias) and 46 tumoral explants of Ce Ca. The explants were cultured for 48 h. The gelatinases secreted into conditioned medium were revealed by zymography and quantified by densitometry. The results showed high levels of MMP-3 and MMP-9 in tumoral explants. In contrast, only the pro-MMP-2 was higher in benign cervical lesions, although both active and inactive MMP-2 species are associated with advanced clinical stages in tumoral samples, and only the secretion of MMP-3 was associated with unresponsiveness to radiotherapy. We can conclude that the expression of MMPs is related to the invasive process in Ce Ca and suggest that they may play a role in degradation of the EM during local invasion. In addition, MMP-3 secretion could be a marker of poor prognosis in Ce Ca.