Human Carcinoma Cell Types Research Articles

In vitro 3D blood/lymph-vascularized human stromal tissues for preclinical assays of cancer metastasis

Tumour models mimicking in vivo three-dimensional (3D) microenvironments are of increasing interest in drug discovery because of the limitations inherent to current models. For example, preclinical assays that rely on monolayer or spheroid cell cultures cannot easily predict 3D cancer behaviours because they have no vasculature. Furthermore, there are major differences in cancer behaviour between human and animal experiments. Here, we show the construction of 3D blood/lymph-vascularized human stromal tissues that can be combined with cancer cells to mimic dynamic metastasis for real-time throughput screening of secreted proteinases. We validated this tool using three human carcinoma cell types that are known to invade blood/lymph vessels and promote angiogenesis. These cell types exhibited characteristic haematogenous/lymphogenous metastasis and tumour angiogenesis properties. Importantly, these carcinoma cells selectively secreted different matrix metalloproteinases depending on their metastasis stage and target vasculature, suggesting the possibility of developing drugs that can target each secreted proteinase. We conclude that the 3D tissue tool will be a powerful throughput system for predicting cancer cell responses and time-dependent secretion of molecules in preclinical assays.

Bioengineering Novel Chimeric microRNA-34a for Prodrug Cancer Therapy: High-Yield Expression and Purification, and Structural and Functional Characterization.

Development of anticancer treatments based on microRNA (miRNA/miR) such as miR-34a replacement therapy is limited to the use of synthetic RNAs with artificial modifications. Herein, we present a new approach to a high-yield and large-scale biosynthesis, in Escherichia coli using transfer RNA (tRNA) scaffold, of chimeric miR-34a agent, which may act as a prodrug for anticancer therapy. The recombinant tRNA fusion pre-miR-34a (tRNA/mir-34a) was quickly purified to a high degree of homogeneity (>98%) using anion-exchange fast protein liquid chromatography, whose primary sequence and post-transcriptional modifications were directly characterized by mass spectrometric analyses. Chimeric tRNA/mir-34a showed a favorable cellular stability while it was degradable by several ribonucleases. Deep sequencing and quantitative real-time polymerase chain reaction studies revealed that tRNA-carried pre-miR-34a was precisely processed to mature miR-34a within human carcinoma cells, and the same tRNA fragments were produced from tRNA/mir-34a and the control tRNA scaffold (tRNA/MSA). Consequently, tRNA/mir-34a inhibited the proliferation of various types of human carcinoma cells in a dose-dependent manner and to a much greater degree than the control tRNA/MSA, which was mechanistically attributable to the reduction of miR-34a target genes. Furthermore, tRNA/mir-34a significantly suppressed the growth of human non-small-cell lung cancer A549 and hepatocarcinoma HepG2 xenograft tumors in mice, compared with the same dose of tRNA/MSA. In addition, recombinant tRNA/mir-34a had no or minimal effect on blood chemistry and interleukin-6 level in mouse models, suggesting that recombinant RNAs were well tolerated. These findings provoke a conversation on producing biologic miRNAs to perform miRNA actions, and point toward a new direction in developing miRNA-based therapies.

Synthesis of O-Me Ulongamide B and O-Me Ulongamide C, Natural Modified Cyclodepsipeptides

Synthesis of O-Me ulongamide B and O-Me ulongamide C, modified natural cyclodepsipeptides, was achieved by a convergent route. The respective dipeptides and tridepsipeptides were coupled, obtaining linear depsipentapeptides, which were then deprotected and cyclized. These compounds were tested against three different types of human carcinoma cells and showed only moderate activity.

Association of overexpressed proline-directed protein kinase F(A) with chemoresistance, invasion, and recurrence in patients with bladder carcinoma.

It has been shown previously that proline-directed protein kinase F(A) (PDPK F(A)) is overexpressed in various human malignancies compared with its expression in normal controls, and the suppression of overexpressed PDPK F(A) is capable of inhibiting the growth of various types of human carcinoma cells, suggesting a role for this PDPK in human malignancies. In this report, the authors combine immunohistologic, molecular, cellular, and clinicopathologic studies to demonstrate further an essential critical role for overexpressed PDPK F(A) in bladder carcinoma invasion, chemoresistance, and poor prognosis. The expression and localization of PDPK F(A) were analyzed by the immunohistochemical staining of specimens obtained from patients with primary transitional cell carcinoma (TCC) of the bladder. The stable antisense clones of human bladder carcinoma cells with specific suppression of overexpressed PDPK F(A) were established for invasion and chemosensitivity studies. The immunohistochemical study revealed that PDPK F(A) was overexpressed preferentially in the invasive bladder carcinoma tissues. It was found that the stable antisense clones with specific suppression of overexpressed PDPK F(A) to approximately 40% of the parental control level were capable of inhibiting the invasive activity and simultaneously enhancing the chemosensitivity of bladder carcinoma cells to various therapeutic drugs, such as vinblastine, vincristine, paclitaxel, and bleomycin. Clinicopathologic studies also revealed a correlation between overexpressed PDPK F(A) and disease recurrence/survival in patients with primary TCC (P < 0.05). Taken together, the results demonstrate an essential critical role of overexpressed PDPK F(A) in invasion, chemoresistance, and poor prognosis. Suppression of overexpressed PDPK F(A) may provide a new potential target for therapeutic intervention aimed at preventing chemoresistance, disease progression, and recurrence in patients with bladder carcinoma.