Stem cells in cancer therapy: From their role in pathogenesis to their use as therapeutic agents

Tumor Chemosensitivity Assays Are Helpful for Personalized Cytotoxic Treatments in Cancer Patients

Tumor chemosensitivity assays (TCAs), also known as drug response assays or individualized tumor response tests, have been gaining attention over the past few decades. Although there have been strong positive correlations between the results of these assays and clinical outcomes, they are still not considered routine tests in the care of cancer patients. The correlations between the assays' results (drug sensitivity or resistance) and the clinical evaluations (e.g., response to treatment, progression-free survival) are highly promising. However, there is still a need to design randomized controlled prospective studies to secure the place of these assays in routine use. One of the best ideas to increase the value of these assays could be the combination of the assay results with the omics technologies (e.g., pharmacogenetics that gives an idea of the possible side effects of the drugs). In the near future, the importance of personalized chemotherapy is expected to dictate the use of these omics technologies. The omics relies on the macromolecules (Deoxyribonucleic acid -DNA-, ribonucleic acid -RNA-) and proteins (meaning the structure) while TCAs operate on living cell populations (meaning the function). Therefore, wise combinations of TCAs and omics could be a highly promising novel landscape in the modern care of cancer patients.

A new complementary procedure for patients affected by head and neck cancer: Chemo-predictive assay

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Cancer stem cells (CSCs) resist chemotherapy, thereby causing relapse of the disease.

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A new chemotherapy drug response assay (ChemoID), which measures the sensitivity of CSCs to a variety of chemotherapy agents has been developed.

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The ChemoID assay may assist an oncologist in making treatment decisions.

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The ChemoID procedure may lower treatment costs by eliminating ineffective chemotherapies and unnecessary toxicity.

Introduction

Administration of ineffective anticancer therapy is associated with unnecessary toxicity and development of resistant clones. Cancer stem cells (CSCs) resist chemotherapy, thereby causing relapse of the disease. Thus, development of a test that identifies the most effective chemotherapy management offers great promise for individualized anticancer treatments. We have developed an ex vivo chemotherapy drug response assay (ChemoID^®), which measures the sensitivity of CSCs as well as the bulk of tumor cells to a variety of chemotherapy agents to assist an oncologist in making treatment decisions.

Methods

Three patients affected by oral cancer were referred.

Results

Biopsy showed a well-differentiated squamous cell carcinoma (G1) in case 1, a G2 adenocarcinoma in case 2 and a G3 squamous cell carcinoma in case 3. In all of the three cases, after clinical inspection and suspicion of a diagnosis of cancer, a double biopsy was performed. One specimen was sent to the ChemoID laboratory for chemosensitivity assay and the other for histological analysis. Chemotherapy dose response curves were generated, and grouped in 3 categories: 1. No response (less than 30% cell kill), Intermediate (30–60% cell kill), and 3. Sensitive (60% cell kill or above).

Conclusions

This procedure may be useful in helping physicians choose an effective chemotherapy regimen for head and neck cancer patients and lower treatment costs by eliminating ineffective chemotherapies and unnecessary toxicity particularly in elderly patients.

Bone and soft tissue non-Hodgkin lymphoma of the maxillofacial area: report of two cases, literature review and new therapeutic strategies

Primary mandibular non-Hodgkin lymphoma (NHL) and soft tissues NHL of the maxillofacial are extremely rare representing a minimal percentage of the head and neck tumors. Two cases of bone and soft tissue maxillofacial NHL are reported. Clinical, radiological and pathological features are described and the therapeutic procedures are discussed accordingly. Mandibular radiologic features have been carefully analyzed and discussed to achieve an early and accurate diagnosis avoiding improper dental therapies.

Chemo-predictive assay for targeting cancer stem-like cells in patients affected by brain tumors

Administration of ineffective anticancer therapy is associated with unnecessary toxicity and development of resistant clones. Cancer stem-like cells (CSLCs) resist chemotherapy, thereby causing relapse of the disease. Thus, development of a test that identifies the most effective chemotherapy management offers great promise for individualized anticancer treatments. We have developed an ex vivo chemotherapy sensitivity assay (ChemoID), which measures the sensitivity of CSLCs as well as the bulk of tumor cells to a variety of chemotherapy agents. Two patients, a 21-year old male (patient 1) and a 5-month female (patient 2), affected by anaplastic WHO grade-III ependymoma were screened using the ChemoID assay. Patient 1 was found sensitive to the combination of irinotecan and bevacizumab, which resulted in a prolonged disease progression free period of 18 months. Following recurrence, the combination of various chemotherapy drugs was tested again with the ChemoID assay. We found that benzyl isothiocyanate (BITC) greatly increased the chemosensitivity of the ependymoma cells to the combination of irinotecan and bevacizumab. After patient 1 was treated for two months with irinotecan, bevacizumab and supplements of cruciferous vegetable extracts containing BITC, we observed over 50% tumoral regression in comparison with pre-ChemoID scan as evidenced by MRI. Patient 2 was found resistant to all treatments tested and following 6 cycles of vincristine, carboplatin, cyclophosphamide, etoposide, and cisplatin in various combinations, the tumor of this patient rapidly progressed and proton beam therapy was recommended. As expected animal studies conducted with patient derived xenografts treated with ChemoID screened drugs recapitulated the clinical observation. This assay demonstrates that patients with the same histological stage and grade of cancer may vary considerably in their clinical response, suggesting that ChemoID testing which measures the sensitivity of CSLCs as well as the bulk of tumor cells to a variety of chemotherapy agents could lead to more effective and personalized anticancer treatments in the future.

Interpretation of interlocking key issues of cancer stem cells in malignant solid tumors

OBJECTIVE

In this review, several interlinking issues related to cancer stem cells (CSCs) in malignant solid tumors are sequentially discussed.

METHODS

A literature search was performed using PubMed, Web of Science and the Cochrane library, combining the words CSCs, solid tumor, isolation, identification, origination, therapy, target and epithelial-mesenchymal transition.

RESULTS

Because a primary problem is the isolation of CSCs, we first analyzed the advantages and disadvantages of recently used methods, which were mostly based on the physical or immunochemical characteristics of CSCs. Once CSCs are isolated, they should be identified by their stem cell properties. Here, we suggest how to establish a standard identification strategy. We also focused on the origination hypotheses of CSCs. The supporting molecular mechanisms for each theory were thoroughly analyzed and integrated. Especially, epithelial- mesenchymal transition is an increasingly recognized mechanism to generate CSCs that are endowed with a more invasive and metastatic phenotype. Finally, we discuss putative strategies of eliminating CSCs as effective cancer therapies.

CONCLUSION

After several interlocking issues of CSCs are thoroughly clarified, these CSCs in solid malignant tumors may specifically be targeted, which raises a new hope for eliminating these tumors.

Stem cell genes are poorly expressed in chondrocytes from microtic cartilage

OBJECTIVES

This study was aimed to see the difference between chondrocytes from normal cartilage compared to chondrocytes from microtic cartilage. Specific attentions were to characterize the growth of chondrocytes in terms of cell morphology, growth profile and RT-PCR analysis.

STUDY DESIGN

Laboratory experiment using auricular chondrocytes.

METHODS

Chondrocytes were isolated from normal and microtic human auricular cartilage after ear reconstructive surgeries carried out at the Universiti Kebangsaan Malaysia Medical Centre. Chondrocytes were cultured in vitro and subcultured until passage 4. Upon confluency, cultured chondrocytes at each passage (P1, P2, P3 and P4) were harvested and subjected to growth profile and gene expression analyses. Comparison was made between the microtic and normal chondrocytes.

RESULTS

For growth profile analysis cell viability did not show significant differences between both samples. There are no significance differences between both samples in terms of its growth rate, except in passage 1 where microtic chondrocytes were significant lower in their growth rate. Population doubling time and total number of cell doubling of all samples also did not show any significant differences. Gene expression is measured using Real Time-Reverse Transcriptase Polymerase Chain Reaction (RT-PCR). There is no significant differences in the expression of collagen type I, collagen type II, collagen type X, aggrecan core protein, elastin and sox9 genes in both samples. There are significant lower in the expression of sox2, nestin, BST-1 and OCT-4 gene in microtic chondrocytes compared to the normal chondrocytes. Stem cells markers are included in this study as stemness in cells may imply a greater proliferative potential and plasticity in vitro.

CONCLUSION

Chondrocytes from microtic samples have the same properties as chondrocytes from normal samples and hold promises to be used as a starting material in the reconstruction of the external ear in future clinical application. The reduction in sox2, nestin, BST-1 and OCT-4 gene expression in microtic samples could be the possible cause of the arrested development of the external ear.