Page 85 - Bio Engineering Approaches to Cancer Diagnosis and Treatment

4.4 Chemo immunotherapy 83

The other subgroup is related to the use of some methods to increase T cell
responses. For instance, increasing tumor antigen presentation can increase the
T cell response. One of the preclinical studies of this subject can be found in
the study of Dewan et al. which was conducted in animal model of mice. They
have injected TSA mouse breast carcinoma cells into mice and after the tumor
was created, they have used an agonist of Toll-like receptor-7 (TLR-7), in com-
bination with three fraction of 8 Gy of RT, and also they have used low-dose
cyclophosphamide before start of treatment with imiquimod and RT. Their results
have shown that with respect to the effect of TLR on the activation of DC and
further increase of T cell response, this therapeutic approach has prevented tumor
growth. And it is important to note that cyclophosphamide has increased the ther-
apeutic effect [35].
The two following methods, vaccine therapy plus RT and the use of monoclonal
antibodies in combination with RT, are important methods that have been considered
in recent years. By introducing tumor antigens, the vaccine therapy stimulates the
immune system against tumor antigens. In a study in 2016, an animal model of mice
with melanoma was used to evaluate the efficacy of RT in combination with vaccine
therapy. Combination treatment with focal RT and LM-based vaccine has been per-
formed. They have used 16 Gy small-animal radiation research platform (SARRP)
7 days after tumor implantation. Then the results of this combined treatment with the
result of using RT alone as a treatment or vaccine alone as treatment, have indicated
that the use of RT as a treatment, minimal inflammation was seen in the treated
tumor. In contrast, by using of LM-vaccination as a treatment, inflammation was
increased. And the results of a treatment with combined method have shown pres-
ence of an intratumoral lymphocyte infiltrate and the results have indicated that the
use of a combined method has led to an increase in the survival of this animal model
with melanoma [36].
The use of antibodies to target antigens in addition to topical radiotherapy as
well as the use of antibodies with other therapeutic methods, such as targeting a spe-
cific cytokine, for instance, TGFβ, to control a cancer treatment has been extremely
attractive for researchers in the last decades. In this regard, Rodríguez-Ruiz et al.
in 2019 has reported the use of monoclonal antibodies with radiotherapy has been
shown to be effective in treating subcutaneous tumors of either 4T1 breast cancer
cells or MC38 colorectal tumors induced in an animal model of mouse. By knowing
that blocking TGFβ leads to an increase in abscopal effect, they have used anti-PD-1
and anti-CD137 monoclonal antibodies plus a TGFβ monoclonal antibody (1D11)
with a regimen local radiotherapy and have managed to find out that the use of this
method has increased the effect of abscopal [37].

4.4 Chemo immunotherapy

As the success rate of antibodies from the earliest humanized forms have not been
less than 15%.