Also, a potent cancer chemotherapeutic agent (FR901228), a histone deacetylase inhibitor, was able to induce endogenous CAR gene expression in several urogenital cancer cells.
We conclude that loss of CAR expression in cancer cells is, at least in part, mediated through the Raf-MEK-ERK signal transduction pathway and that pharmacological restoration of CAR at the cell surface could improve adenovirus-based treatments of cancer.
However, minimal or absent expression of the adenovirus serotype 5 (Ad5) receptor CAR (coxsackievirus and adenovirus receptor) on cancer cells represents a major limitation for Ad5-based oncolysis.
We also found that CAR expression in the target cancer cells is an important factor for the efficacy of selectively replicated adenovirus-based gene therapy.
In order to overcome the low infectivity of the adenoviral vectors for breast cancer cells, and to increase the safety and efficacy for cancer gene therapy, this vector was further modified on a transductional level by simultaneously ablating the native tropism of the vector to the primary CAR receptor and inserting a RGD-4C peptide into the HI loop of the fiber, which allows the vector to use the alphavbeta3 and alphavbeta5 receptors as alternative receptors.
In conclusion, soluble CAR isoforms 3/7 and 4/7 may play a pivotal role in ovarian cancer biology, possibly by counteracting migration- and growth-inhibitory properties of the membranous hCAR and thus favoring cancer cell dissemination throughout the peritoneal cavity.
However, poor infection efficiency with coxsackievirus and adenovirus receptor (CAR) down-regulated cancer cell lines is one of the major challenges for its practical and extensive application.
Based on these preclinical data, we anticipate that adoptive therapy using CAR-targeted T cells modified to secrete IL-12 will obviate or reduce the need for potentially hazardous conditioning regimens to achieve optimal antitumor responses in cancer patients.
Extending the use of CAR therapies to cancers other than B-cell malignancies will require selective tumor targeting with minimal or acceptable "on-target, off-tumor" effects.
Adoptive transfer of T lymphocytes expressing a CD19-specific chimeric antigen receptor (CAR.CD19) induces complete tumor regression in patients with lymphoid malignancies.
Using optimized electroporation voltage, interleukin-15 alone and co-culturing CAR T cells with peripheral blood mononuclear cells, we were able to expand CAR19 T-cell cultures by up to 765-fold over 3 weeks in normal donors and 180-fold in patients with B-cell malignancies.
These results demonstrate that the Tol2 transposon system could be used to express CD19-CAR in genetically engineered T-cells for the treatment of refractory B-cell malignancies.
Adenovirus (Ad) is a widely used vector for cancer gene therapy but its therapeutic efficacy is limited by low coxsackievirus and adenovirus receptor (CAR) expression in tumors and non-specifically targeted infection.
Clinical trials in patients with advanced B cell malignancies treated with CD19-specific CAR-modified T cells (CAR-T) have shown impressive antitumor efficacy, leading to optimism that this approach will be useful for treating common solid tumors.
A handful of trials are targeting non-CD19 hematological and solid malignancies and represent the vanguard of enormous preclinical efforts to develop CAR T-cell therapy beyond B-cell malignancies.
This first evaluation of the safety and efficacy of HER2-CAR T cells in patients with cancer shows the cells can persist for 6 weeks without evident toxicities, setting the stage for studies that combine HER2-CAR T cells with other immunomodulatory approaches to enhance their expansion and persistence.
Chimeric antigen receptor-modified T cells (CAR-T) have emerged as a new modality for cancer immunotherapy due to their potent efficacy against terminal cancers.
CAR-T cells harness the effector function of the adaptive arm of the immune system and redirect it against cancer cells, overcoming the major challenges of immunotherapy, such as breaking tolerance to self-antigens and beating cancer immune system-evasion mechanisms.