The density of infiltrating T cells and macrophages in the parental tumour correlates with growth rate of tumoroids established from colorectal adenocarcinoma

The aim of the present study was to investigate the correlation between the density of infiltrating T cells and macrophages in the parental colorectal cancer (CRC) and the growth rate of tumoroids (i.e. a patient-derived in vitro 3D model). Tumoroids were established from fresh specimens of primary and metastatic CRC from 29 patients. The in vitro growth rate of tumoroids was monitored by automated imaging. The density of infiltrating T cells and macrophages was determined in the centre of the tumour (CT) and at the invasive margin (IM) of the parental tumours. This was performed by digital image analysis on the whole-slide scanned images using Visiopharm^® software. Tumoroids with higher density of infiltrating CD3+ lymphocytes in the IM of their parental tumour showed a higher growth rate (P < .0005). The average relative growth rate (log10) during the period from day 1 to day 11 was 0.364 ± 0.006 (mean ± SD) for the CD3+ (IM)-high group and 0.273 ± 0.008 (mean ± SD) for the CD3+ (IM)-low group. In contrast, the density of CD68+ infiltrating macrophages in the parental tumours showed significant inverse effect on the growth rate of the tumoroids (P < .0005). The present study showed that the density of immune cells in the parental CRC correlates with the growth rate of the tumoroids. The future perspective for such a 3D model could be in vitro investigations of the tumour-associated inflammatory microenvironment as well as personalized cancer immunotherapy.

Nuclear competence and genetic expression of growth differentiation factor-9 (GDF-9) of canine oocytes in 3D culture

To evaluate the ability of a 3D culture system in improving the nuclear and molecular competence of canine oocytes, barium alginate microcapsules were used for in vitro maturation (IVM) and the expression profile of one selected oocyte-secreted factor, the growth differentiation factor-9 (GDF-9) was analysed. In Experiment I, canine grade I cumulus-oocyte complexes (COCs) were in vitro matured in 3D microcapsules in a controlled atmosphere for 72 hr, and meiosis resumption rates were compared to those of oocytes cultured in traditional 2D microdrops of medium. In Experiment II, a primer pair specific for canine GDF-9 was designed, and preliminary tested in conventional PCR on genomic DNA. Total RNA content was isolated from oocytes at different time intervals (T0-T24-T48-T72) during in vitro 3D culture, and a reverse transcription to cDNA was performed. The expression of target gene was assessed by quantitative Reverse Transcription Real-Time PCR (qRT-PCR), and the obtained amplicons were sequenced to check the specificity of the analysis. Canine COCs resumed meiosis at higher rates in 3D microcapsules than in 2D microdrops (p < 0.05), even though no significant differences in the proportions of oocytes achieving full maturational stages were obtained. A significant dynamic decrease in GDF-9 expression was recorded during culture: after 72 hr of IVM, the GDF-9 transcription significantly dropped (p = 0.018) compared to 24 and 48 hr. In conclusion, in vitro 3D culture represents an efficient system for IVM of canine oocytes, and the expression profile of GDF-9 well reflects temporal dynamics for the acquisition of developmental competence in this species.

A three-dimensional cell culture system as an in vitro canine mammary carcinoma model for the expression of connective tissue modulators

In this study, derived complex carcinoma (CC) and simple carcinoma (SC) cell lines were established and cultured under two-dimensional (2D) and three-dimensional (3D) conditions. The 3D was performed in six-well AlgiMatrix™ (LifeTechnologies®, Carlsbad, CA, USA) scaffolds, resulting in spheroids sized 50-125 µm for CC and 175-200 µm for SC. Cell viability was demonstrated up to 14 days for both models. Epidermal growth factor receptor (EGFR) was expressed in CC and SC in both systems. However, higher mRNA and protein levels were observed in SC 2D and 3D systems when compared with CC (P < 0.005). The connective tissue modulators, metalloproteinases-1, -2, -9 and -13 (MMPs), relaxin receptors 1 and 2 (RXR1 and RXR2) and E-cadherin (CDH1) were quantitated. All were upregulated similarly when canine mammary tumour (CMT)-derived cell lines were cultured under 3D AlgiMatrix, except CDH1 that was downregulated (P < 0.005). These results are promising towards the used of 3D system to increase a high throughput in vitro canine tumour model.

Human single follicle growth in vitro from cryopreserved ovarian tissue after slow freezing or vitrification

STUDY QUESTION

What is the effect of human ovarian tissue cryopreservation on single follicular development in vitro?

SUMMARY ANSWER

Vitrification had a greater negative effect on growth and gene expression of human ovarian follicles when compared with fresh follicles.

WHAT IS KNOWN ALREADY

For human ovarian cortex cryopreservation, the conventional option is slow freezing while more recently vitrification has been demonstrated to maintain good quality and function of ovarian tissues.

STUDY DESIGN, SIZE, DURATION

Ovarian tissues were collected from 11 patients. For every patient, the ovarian cortex was divided into three samples: Fresh, slow-rate freezing (Slow) and vitrification (Vit). Tissue histology was performed and follicles were isolated for single-cell mRNA analysis and in vitro culture (IVC) in 1% alginate for 8 days.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Follicle morphology was assessed with hematoxylin-eosin analysis. Follicles were individually embedded in alginate (1% w/v) and cultured in vitro for 8 days. Follicle survival and growth were assessed by microscopy. Follicle viability was observed after Calcein-AM and ethidium homodimer-I (Ca-AM/EthD-I) staining. Expression of genes, including GDF9 (growth differentiation factor 9), BMP15 (bone morphogenetic protein 15) and ZP3 (zona pellucida glycoprotein 3) in oocytes and AMH (anti-Mullerian hormone), FSHR (FSH receptor), CYP11A (cholesterol side-chain cleavage cytochrome P450) and STAR (steroidogenic acute regulatory protein) in GCs, was evaluated by single-cell mRNA analysis.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 129 follicles were separated from ovarian cortex (Fresh n = 44; Slow n = 40; Vit n = 45). The percentage of damaged oocytes and granulosa cells was significantly higher in both the Slow and Vit groups, as compared with Fresh control (P< 0.05). The growth of follicles in vitro was significantly delayed in the Vit group compared with the Fresh group (P< 0.05). Both slow freezing (P< 0.05) and vitrification (P< 0.05) down-regulated the mRNA levels of ZP3 and CYP11A compared with Fresh group, while there was no significant difference between the Slow and Vit groups (P> 0.05). Vitrification also down-regulates AMH mRNA levels compared with Fresh group (P< 0.05).

LIMITATIONS, REASONS FOR CAUTION

Only short-term IVC studies (8 days) are reported. Further study should be performed to examine and improve follicular development in a long-term culture system after cryopreservation.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first comparison of gene expression and growth of single human ovarian follicles in vitro after either slow freezing or vitrification. With the decreased gene expression and growth during IVC, damage by cryopreservation still exists and needs to be minimized during the long-term IVC of follicles in the future for eventual clinical application.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by the National Natural Science Foundation of China (31230047, 81571386, 81471508, 31429004 and 81501247), National Natural Science Foundation of Beijing (7142166) and Mega-projects of Science Research for the 12th five-year plan (2012ba132b05). There are no conflicts of interest to declare.

Basic fibroblast growth factor promotes the development of human ovarian early follicles during growth in vitro

STUDY QUESTION

What is the effect of basic fibroblast growth factor (bFGF) on the growth of individual early human follicles in a three-dimensional (3D) culture system in vitro?

SUMMARY ANSWER

The addition of 200 ng bFGF/ml improves human early follicle growth, survival and viability during growth in vitro.

WHAT IS KNOWN ALREADY

It has been demonstrated that bFGF enhances primordial follicle development in human ovarian tissue culture. However, the growth and survival of individual early follicles in encapsulated 3D culture have not been reported.

STUDY DESIGN, SIZE, DURATION

The maturation in vitro of human ovarian follicles was investigated. Ovarian tissue (n= 11) was obtained from 11 women during laparoscopic surgery for gynecological disease, after obtaining written informed consent. One hundred and fifty-four early follicles were isolated by enzymic digestion and mechanical disruption. They were individually encapsulated into alginate (1% w/v) and randomly assigned to be cultured with 0, 100, 200 or 300 ng bFGF/ml for 8 days.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Individual follicles were cultured in minimum essential medium α (αMEM) supplemented with bFGF. Follicle survival and growth were assessed by microscopy. Follicle viability was evaluated under confocal laser scanning microscope following Calcein-AM and Ethidium homodimer-I (Ca-AM/EthD-I) staining.

MAIN RESULTS AND THE ROLE OF CHANCE

After 8 days in culture, all 154 follicles had increased in size. The diameter and survival rate of the follicles and the percentage with good viability were significantly higher in the group cultured with 200 ng bFGF/ml than in the group without bFGF (P < 0.05). The percentage of follicles in the pre-antral stage was significantly higher in the 200 ng bFGF/ml group than in the group without bFGF (P < 0.05), while the percentages of primordial and primary follicles were significantly lower (P < 0.05).

LIMITATIONS, REASONS FOR CAUTION

The study focuses on the effect of bFGF on the development of individual human early follicles in 3D culture in vitro and has limited ability to reveal the specific effect of bFGF at each different stage. The findings highlight the need to improve the acquisition and isolation of human ovarian follicles.

WIDER IMPLICATIONS OF THE FINDINGS

The in vitro 3D culture of human follicles with appropriate dosage of bFGF offers an effective method to investigate their development. Moreover, it allows early follicles to be cultured to an advanced stage and therefore has the potential to become an important source of mature oocytes for assisted reproductive technology; particularly as an option for fertility preservation in women, including patients with cancer.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the National Basic Research Program of China (2011|CB944504, 2011CB944503) and the National Natural Science Foundation of China (81200470, 81000275, 31230047, 8110197). There are no conflicts of interest to declare.