Differences in chemosensitivity between primary and paired metastatic lung cancer tissues: In vitro analysis based on the collagen gel droplet embedded culture drug test (CD-DST)

Radiosensitivity of Breast Cancer Cells Is Dependent on the Organ Microenvironment

Background

Distant metastasis is the leading risk factor of death in breast cancer patients, with lung and liver being commonly involved sites of distant seeding. Ongoing clinical trials are studying the benefit from additional local treatment to these metastatic sites with radiation therapy. However, little is known about the tissue-specific microenvironment and the modulating response to treatments due to limitations of traditional in vitro systems. By using biomatrix scaffolds (BMSs) to recreate the complex composition of extracellular matrices in normal organs, we chose to study the radiotherapy response with engineered breast cancer “metastases” in liver and lung organ-specific tissues.

Methods

Liver and lung BMSs were prepared for tissue culture. Human breast cancer cell lines were passaged on normal tissue culture plates or tissue culture plates coated with Matrigel, liver BMSs, and lung BMSs. Clonogenic assays were performed to measure cell survival with varying doses of radiation. Reactive Oxygen Species (ROS) detection assay was used to measure ROS levels after 6 Gy irradiation to cancer cells.

Results

The response of breast cell lines to varying doses of radiotherapy is affected by their in vitro acellular microenvironment. Breast cancer cells grown in liver BMSs were more radiosensitive than when grown in lung BMSs. ROS levels for breast cancer cells cultured in lung and liver BMSs were higher than that in plastic or in Matrigel plate cells, before and after radiotherapy, highlighting the interaction with surrounding tissue-specific growth factors and cytokines. ROSs in both lung and liver BMSs were significantly increased after radiotherapy delivery, suggesting these sites create prime environments for radiation-induced cell death.

Conclusions

The therapeutic response of breast cancer metastases is dependent on the organ-specific microenvironment. The interaction between tissue microenvironment in these organs may identify sensitivity of therapeutic drug targets and radiation delivery for future studies.

Benefits of functional assays in personalized cancer medicine: more than just a proof-of-concept

As complex and heterogeneous diseases, cancers require a more tailored therapeutic management than most pathologies. Recent advances in anticancer drug development, including the immuno-oncology revolution, have been too often plagued by unsatisfying patient response rates and survivals. In reaction to this, cancer care has fully transitioned to the “personalized medicine” concept. Numerous tools are now available tools to better adapt treatments to the profile of each patient. They encompass a large array of diagnostic assays, based on biomarkers relevant to targetable molecular pathways. As a subfamily of such so-called companion diagnostics, chemosensitivity and resistance assays represent an attractive, yet insufficiently understood, approach to individualize treatments. They rely on the assessment of a composite biomarker, the ex vivo functional response of cancer cells to drugs, to predict a patient's outcome. Systemic treatments, such as chemotherapies, as well as targeted treatments, whose efficacy cannot be fully predicted yet by other diagnostic tests, may be assessed through these means. The results can provide helpful information to assist clinicians in their decision-making process. We explore here the most advanced functional assays across oncology indications, with an emphasis on tests already displaying a convincing clinical demonstration. We then recapitulate the main technical obstacles faced by researchers and clinicians to produce more accurate, and thus more predictive, models and the recent advances that have been developed to circumvent them. Finally, we summarize the regulatory and quality frameworks surrounding functional assays to ensure their safe and performant clinical implementation. Functional assays are valuable in vitro diagnostic tools that already stand beyond the “proof-of-concept” stage. Clinical studies show they have a major role to play by themselves but also in conjunction with molecular diagnostics. They now need a final lift to fully integrate the common armament used against cancers, and thus make their way into the clinical routine.

Lopinavir-NO, a nitric oxide-releasing HIV protease inhibitor, suppresses the growth of melanoma cells in vitro and in vivo

We generated a nitric oxide (NO)-releasing derivative of the anti-HIV protease inhibitor lopinavir by linking the NO moiety to the parental drug. We investigated the effects of lopinavir and its derivative lopinavir-NO on melanoma cell lines in vitro and in vivo. Lopinavir-NO exhibited a twofold stronger anticancer action than lopinavir in vitro. These results were successfully translated into syngeneic models of melanoma in vivo, where a significant reduction in tumour volume was observed only in animals treated with lopinavir-NO. Both lopinavir and lopinavir-NO inhibited cell proliferation and induced the trans-differentiation of melanoma cells to Schwann-like cells. In melanoma cancer cell lines, both lopinavir and lopinavir-NO induced morphological changes, minor apoptosis and reactive oxygen species (ROS) production. However, caspase activation and autophagy were detected only in B16 cells, indicating a cell line-specific treatment response. Lopinavir-NO released NO intracellularly, and NO neutralization restored cell viability. Treatment with lopinavir-NO induced only a transient activation of Akt and inhibition of P70S6 kinase. The results of this study identify lopinavir-NO as a promising candidate for further clinical trials in melanoma and possibly other solid tumours.

Acquisition of Cholangiocarcinoma Traits during Advanced Hepatocellular Carcinoma Development in Mice

Past studies have identified hepatic tumors with mixed hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC) characteristics that have a more aggressive behavior and a poorer prognosis than classic HCC. Whether this pathologic heterogeneity is due to a cell of origin of bipotent liver progenitors or the plasticity of cellular constituents comprising these tumors remains debated. In this study, we investigated the potential acquisition of CC-like traits during advanced development of HCC in mice. Primary and rare high-grade HCC developed in a genetic mouse model. A mouse model of highly efficient HCC invasion and metastasis by orthotopic transplantation of liver cancer organoids propagated from primary tumors in the genetic model was further developed. Invasive/metastatic tumors developed in both models closely recapitulated advanced human HCC and displayed a striking acquisition of CC-related pathologic and molecular features, which was absent in the primary HCC tumors. Our study directly demonstrates the pathologic evolution of HCC during advanced tumor development, providing the first evidence that tumors with mixed HCC and CC features, or at least a subset of these tumors, represent a more advanced developmental stage of HCC. Finally, liver cancer organoid-generated high-grade tumors exhibited significantly increased extracellular vesicle secretion, suggesting that identifying tumor-specific extracellular vesicle proteins in plasma may be a promising tool for liver cancer detection.

Effect of wound fluid on chemotherapy sensitivity of T24 bladder cancer cells with different enhancer of zeste homolog 2 status

The present study investigated the effect of zeste homolog 2 (EZH2) and wound fluid (WF) on chemotherapy sensitivities of T24 bladder cancer cells by using a collagen gel droplet embedded culture-drug sensitivity test (CD-DST). T24 bladder cancer cells with different EZH2 expression levels were co-cultured with postoperative WF from patients with bladder cancer. The CD-DST was performed to detect the sensitivity of tumor cells to gemcitabine and cis-diamminedichloridoplatinum (II) (cisplatin, DDP). The survival rates of the bladder cancer cells were used to determine the drug's chemotherapeutic effect. EZH2 knockdown increased the sensitivity of the cells to gemcitabine and DDP, whereas EZH2 overexpression decreased the chemotherapeutic sensitivity. Except for the situation of EZH2 overexpression, co-culturing with WF induced significantly higher drug resistance in tumor cells. Overexpression of EZH2 and surgery-induced WF promoted the drug resistance of bladder cancer cells to the investigated chemotherapeutic agents, suggesting that more studies are needed to investigate the key mechanisms underlying the EZH2- and WF-induced reduction of susceptibility to chemotherapy drugs.

Impact of in vitro chemosensitivity test-guided platinum-based adjuvant chemotherapy on the surgical outcomes of patients with p-stage IIIA non-small cell lung cancer that underwent complete resection

The impact of in vitro chemosensitivity test-guided platinum-based adjuvant chemotherapy on the surgical outcomes of patients undergoing complete resection for locally advanced non-small cell lung cancer (NSCLC) has yet to be elucidated. In the present study, the utility of adjuvant chemotherapy based on the collagen gel droplet embedded culture drug sensitivity test (CD-DST) in patients with p (pathology)-stage IIIA NSCLC was retrospectively analyzed. A series of 39 patients that had received platinum-based adjuvant chemotherapy following complete resection between 2007 and 2012 were enrolled. Their surgical specimens were subjected to the CD-DST. The patients were subsequently classified into two groups on the basis of in vitro anti-cancer drug sensitivity data obtained using the CD-DST: The sensitive group (25 patients) were treated with regimens including one or two of the anti-cancer drug(s) that were indicated to be effective by the CD-DST, whereas the non-sensitive group (14 patients) were treated with chemotherapy regimens that did not include any CD-DST-selected anti-cancer drugs. There were no significant differences in the background characteristics of the two groups [including in respect of the pathological TN (tumor-lymph node) stage, tumor histology, epidermal growth factor receptor mutation status, the frequency of each chemotherapy regimen, and the number of administered cycles]. The 5-year disease-free survival (DFS) rate of the sensitive group was 32.3%, whereas that of the non-sensitive group was 14.3% (P=0.037). In contrast, no difference in overall survival (OS) was observed (P=0.76). Multivariate analysis revealed that adjuvant chemotherapy based on the CD-DST had a significant favorable effect on the DFS (P=0.01). Therefore, the present study has demonstrated that CD-DST data obtained from surgical specimens aid the selection of effective platinum-based adjuvant chemotherapy regimens for patients undergoing complete resection for p-stage IIIA NSCLC. The use of CD-DST-guided platinum-based regimens may have a beneficial impact on the DFS of such patients.

Influence of wound fluid on chemotherapy sensitivity in primary breast cancer cells

Objective

To investigate the effect of WF on chemotherapy sensitivities of primary breast cancer cells from breast cancer patients by using CD-DST.

Results

In general, the WF-treated cells showed remarkable increase in survival rates as compared to the control cells cultured without WF among different anticancer drug subgroups. This trend was generally observed in all the tumor cells from the premenopausal, postmenopausal, T2, N0, N1, luminal B, and TN patients.

Methods

The sensitivities of WF-treated primary breast cancer cells, from 21 patients who underwent a radical resection for breast cancer from September 2014 to July 2015, to anticancer drugs: EPI, CDDP, DOC, VNR, 5-FU+LV, and PAC, were obtained using CD-DST. The survival rates of the breast cancer cells were recorded and used to gauge the chemotherapeutic effect.

Conclusions

Surgery-induced WF promotes the drug resistance of primary breast cancer cells to chemotherapy, suggesting that surgery may have adverse effects on breast cancer patients. More studies are needed to investigate the key factors in WF that enhance the susceptibility to chemotherapy drugs.

Chemosensitivity and resistance testing in malignant effusions with focus on primary malignant mesothelioma and metastatic adenocarcinoma

Cell based chemosensitivity and resistance testing is an attractive approach that offers functional measurement of drug response ex vivo with the ultimate goal to guide the choice of chemotherapy for various cancers. Thus, it has a great potential to select patients for the optimal treatment option, thereby offering a tool for personalized cancer therapy. Despite several decades of intensive scientific efforts ex-vivo tests are still not incorporated in the standard of care. Limited access to fresh tumor tissue, unsatisfactory models and single readout as endpoint constitute major hindrance. Thus, establishing and validating clinically useful and reliable model systems still remains a major challenge. Here we present malignant effusions as valuable sources for ex-vivo chemosensitivity and resistance testing. Accumulation of a malignant effusion in the pleura, peritoneum or pericardium is often the first diagnostic material for both primary malignant mesothelioma and a broad spectrum of metastatic adenocarcinoma originating from lung-, breast-, ovary- and gastro-intestinal organs as well as lymphoma. In contrast to biopsies, in these effusions malignant cells are easily accessible and often abundant. Effusion derived cells can occur dissociated or forming three-dimensional papillary structures that authentically recapitulate the biology of the corresponding tumor tissue and offer models for ex vivo testing. In addition, effusions have the advantage of being available prior to or concurrent with the pathological review, thus constituting an excellent source of viable cells for simultaneous molecular profiling, biomarker analysis and for establishing primary cells for studying tumor biology and resistance mechanisms. For a reliable test, however, a careful validation is needed, taking into account the inherited heterogeneity of malignant tumors, but also the complex interplay between malignant and benign cells, which are always present in this setting.

Application of single-cell RNA sequencing in optimizing a combinatorial therapeutic strategy in metastatic renal cell carcinoma

BACKGROUND

Intratumoral heterogeneity hampers the success of marker-based anticancer treatment because the targeted therapy may eliminate a specific subpopulation of tumor cells while leaving others unharmed. Accordingly, a rational strategy minimizing survival of the drug-resistant subpopulation is essential to achieve long-term therapeutic efficacy.

RESULTS

Using single-cell RNA sequencing (RNA-seq), we examine the intratumoral heterogeneity of a pair of primary renal cell carcinoma and its lung metastasis. Activation of drug target pathways demonstrates considerable variability between the primary and metastatic sites, as well as among individual cancer cells within each site. Based on the prediction of multiple drug target pathway activation, we derive a combinatorial regimen co-targeting two mutually exclusive pathways for the metastatic cancer cells. This combinatorial strategy shows significant increase in the treatment efficacy over monotherapy in the experimental validation using patient-derived xenograft platforms in vitro and in vivo.

CONCLUSIONS

Our findings demonstrate the investigational application of single-cell RNA-seq in the design of an anticancer regimen. The approach may overcome intratumoral heterogeneity which hampers the success of precision medicine.

An engineered three-dimensional gastric tumor culture model for evaluating the antitumor activity of immune cells in vitro

Monolayer tumor culture models have been used for evaluating the antitumor activity of immune cells in vitro. However, their value in this research is limited. We used human gastric cancer cells (BGC823) and collagen hydrogel as a matrix to establish an engineered three-dimensional (3-D) tumor culture model in vitro. Tumor cells grew in 3-D culture and formed spheroids in the collagen matrix. Evaluation of the antitumor activity of cytokine-induced killer (CIK) cells revealed that, compared with the 2-D cell culture models, CIK cells migrated towards the tumor cells and destroyed the spheroids and tumor cells in the engineered 3-D tumor culture model. The cytotoxicity of CIK cells against the tumor cells in the engineered 3-D tumor culture model was lower than that in 2-D tumor culture models at 12–36 h post-interaction, but there was no significant difference in the cytotoxicity at later time points. Further analysis indicated that dendritic cell-activated CIK cells had a significantly higher level of cytotoxicity against tumor cells, compared with CIK and anti-CEA/CD3-treated CIK cells, in the engineered 3-D tumor culture model. Our data suggest that the engineered 3-D gastric tumor culture model may better mimic the interaction of immune cells with tumor cells in vivo than the 2-D tumor culture models, and may be used for evaluating the antitumor activity of immune cells in vitro.