Adenosine And Imunosuppression

A key factor in the development of tumors is the ability of cancerous cells to evade recognition from the bodies’ natural defense against cancer, the immune system. Immunotherapies effectively block the pathways that shield cancerous cells from being identified, and thus the promote the bodies own anti-tumor response. However, one challenge to immunotherapy has been its combination with chemotherapy, the mainstay of cancer treatment. While chemotherapy is extremely effective in stopping the rapid division of cancerous cells, its toxic immunosuppressive side-effect make it difficult to combine with

So, with this increase in toxicity over single agent inhibition of the PD-1 checkpoint, an increase in efficacy would be required to support development of the combination. At the doses of tremelimumab considered tolerable, among PD-L1 positive patients (based on staining in 25% of the cancer cells), the response rate does not appear superior to single agent PD-1 inhibition.2,4 However, among those without high level PD-L1 expression, 4 of 14 patients responded to the combination, while with approved agents, no more than 2 patients would anticipated to respond.2,4

Allison hypothesized that “if the CTLA-4 molecular brake could be temporarily disabled, the immune system would be able to launch a more vigorous attack on cancer cells, resulting in the shrinkage of tumors. ” From this hypothesis, Allison and his colleagues set out to test the theory by delivering a synthetically developed antibody that obstructs CTLA-4 activity to mice. Wolchok did not identify a research question of hypothesis for the studies involving a second immune system-braking molecule known as PD-1, which is a molecule on the surface of many T cells that initiates self-destruction of a cell after coming in contact with cancer cells. Other than the hypothesize provided by James Allison, Wolchok does not provide other specific hypothesis or research questions that are intended to be

Cancer immunotheraphy is a concept that has been around for centuries. Back in the 1800s, a bone surgeon named William Coley injected his patients with a vaccine consisting of killed bacteria hoping it would stimulate the body's defense system. During the 1990s, physicians treated people with cancer with a cytokine treatment. This treatment involved high amounts of interleuken-2 (IL-2) and interferon-γ (IFNγ), also known as inflammatory cytokines. These inflammatory cytokines were released by white blood cells that fight infection (T cells). However, this treatment can have very dangerous side effects such as vascular leakage and kidney damage, but some people that received the cytokine treatment have lived for decades. In the year of 1996,

The normal cancer-fighting response from the immune system activates white blood cells, also called T cells, which target cancer cells in the area. The cancer-fighting cells also

The cancer cells had spread into the dermis and even into the subcutaneous layer of the skin. The cells with pleomorphic nuclei that were in the epidermis were surrounding the main tumor. Since the cancer had reached this stage, the immune system was actively trying to fight this disease.6 The lymphocytes were producing antibodies to combat the cancer cells which were considered as a threat to the body. They were also trying to get rid of the foreign tissue that might be present.

Therefore, dose and duration of treatment is limited, which in turn limits the amount of normal and tumor cell death. A second mechanism is the suppression of cancer cells for variable periods of time without cell death. This mechanism is referred to as remission. Unfortunately, the cancer can return at any time, and it is sometimes stronger. Here another limitation is introduced. Some tumor cells can develop resistance to a particular chemical agent, or several chemical agents, limiting the types of chemotherapeutic agents available for effective use. The last mechanism is cell differentiation, which helps the immune system learn to recognize and fight tumor cells (1).

Knapton, Sarah. "Sleeping Immune Cells in Tumours Can Be 'woken Up' to Fight Cancer." The Telegraph. Telegraph Media Group, 15 Apr. 2016. Web. 16 Apr.

While drugs that inhibit cancer – such as Tecentriq by Genentech – are effective in fighting some cancers, in diabetes, the PD-L1 needed to be boosted. The protein, called an immune checkpoint because it prevents T cells from recognizing and attacking cancer, is instrumental in crippling autoreactive T cells that destroy cells which produce insulin, Fierce Biotech reported.

As the world continues to suffer from these devastating diseases, researchers continue to find alternative therapeutic ways of addressing cancer treatment. It is on this premise that various immunotherapeutic alternatives have emerged and currently garnering the greatest level of attention and already raising hope throughout the world in addressing the treatment of NSCLC. However, this can no longer be viewed as a discovery but a wave in the medicine world that began in the 20th century. Various researchers have found the importance of the role of immune systems in fighting the growth of tumor caused by cancer cells. A study by Huncharek (2000) stated that specific immune boosters are capable of eliminating preclinical cancers. In contrast, Jermal et al. (2011) found that immunotherapy is an effective approach for the treatment of tumors that have already turned into solid. Similarly, the researchers highlighted that immunotherapy can be an effective approach to the treatment of melanoma as well as renal cell cancers (Lasalvia-Prisco, 2008). However, Jemal et al. (2011) noted that immunotherapy cannot achieve much in cancer treatment due to limitation brought about by the emission of immunosuppressive cytokines and subsequent loss of antigen expressions. Recent development in research studies on the immunotherapy approach to cancer treatment continues to elicit mixed reactions among researchers of medicinal ecology (Jadad et al., 1996). However, recent development in

The mechanisms observed from various preliminary studies have led researchers to determine that antibody mediated blockade of the PD-1/PD-L1 pathway should have positive effects on tumor regression. This has led to the development of various drugs to target the PD-1/PD-L1 pathway. In the last decade, checkpoint inhibitory drugs have been utilized to increase cancer survival rates by blocking the PD-1--PD-L1 pathway interactions . By blocking this pathway, various immune cells such as CTLs, NK, and DCs can properly detect cancer cells and trigger T-cell activation thus enabling tumor cell apoptosis.

This letter is written in support of Dr. Rodney Macedo Gonzales application for a CRI Irvington Postdoctoral Fellowship studying the role of chemokine inhibition in the melanoma treatment under the mentorship of Dr. Ran Reshef. During the last few years, I have worked closely and collaborated on several projects with Dr. Reshef. These efforts have resulted in multiple publications using chemokine inhibition for reducing immune-related effects in GvHD and other diseases. Now with Rodney as part of his team, they are planning to use this strategy for improving the effect of PD-1/CTLA-4 blocking in melanoma, as well as reducing the immune-related toxicity observed in these patients after treatment.

At present, chemotherapy is the main systemic treatment option for TNBC patients. This study suggests a potential role for CDK7 in modulating the sensitivity of TNBC cells to the chemotherapeutic agent doxorubicin. This may provide additional therapeutic strategies for the fraction of TNBC patients with poor inherent response to doxorubicin, as well as those displaying residual disease following good initial response to treatment. A moderate level of increased sensitivity was also observed following CDK7 knockdown with carboplatin treatment, but not with docetaxel treatment, suggesting that the apparent protective effect mediated by CDK7 may be limited to genotoxic agents. Previous studies demonstrated that CDK7 played a positive role in DNA

Many trial investigations have served to understand the effectiveness of PD-1—PD-L1 inhibitors in conjunction with current standard therapies such as chemotherapy, radiation, and surgical removal of tumors. In a study conducted by Guo. Et al., Trabectedin, a commonly used therapy used to treat ovarian cancer, and an anti-PD-1 monoclonal antibody were used to provide evidence that combined treatment therapies can have antitumor effects in mice with ovarian cancer(52). Mice underwent tumor transplantations and were treated with either a single (control) or combined Trabectidin and alpha-PD-1 mAb dose. Trabectedin was administered intravenously at a dose of 200 ug/kg body weight once per week for 3 weeks while alpha-PD-1 mAb was peritoneally

Most PD-1/PD-L1 inhibitory drugs have been shown to be relatively safe, with very little evidence of toxicity in patients who receive these drugs (37). In some instances, however, drug related toxicity has occurred. For example, Rosenberg et. al. administered 1200 mg of Atezolizumab daily for a period of 21 days to 315 patients with metastatic urothelial carcinoma. At the end of the study, 310 patients discontinued treatment and of those 193 patients had died. Additionally, 8 patients withdrew and 1 discontinued for other reasons. Adverse events were reported in 300 of the 310 patients which included: fatigue, rash and dyspnoea. A total of 55% of patients experienced a grade 3-4 adverse event , 69% had treatment related adverse events, however, no treatment related deaths occurred.(55)