Oblimersen (INN, trade name Genasense; also known as Augmerosen and bcl-2 antisense oligodeoxynucleotide G3139) is an antisenseoligodeoxyribonucleotide being studied as a possible treatment for several types of cancer, including chronic lymphocytic leukemia, B-cell lymphoma, and breast cancer. It may kill cancer cells by blocking the production of Bcl-2—a protein that makes cancer cells live longer—and by making them more sensitive to chemotherapy.
The antisense oligonucleotide drug oblimersen was developed by Genta Incorporated to target Bcl-2. An antisense DNA or RNA strand is non-coding and complementary to the coding strand (which is the template for producing respectively RNA or protein). An antisense drug is a short sequence of RNA which hybridises with and inactivates mRNA, preventing the protein from being formed.[citation needed]
It was shown that the proliferation of human lymphomacells (with t(14;18) translocation) could be inhibited by antisense RNA targeted at the start codon region of Bcl-2 mRNA. In vitro studies led to the identification of oblimersen, which is complementary to the first 6 codons of Bcl-2 mRNA.[1]
These have shown successful results in Phase I/II trials for lymphoma, and a large Phase III trial was launched in 2004.[2]
By the first quarter 2010, the drug had not received FDA approval due to disappointing results in a melanoma trial. Although its safety and efficacy have not been established for any use, Genta Incorporated still[when?] claims on its website that studies are currently under way to examine the potential role of oblimersen in a variety of clinical indications.
Recent studies in 2023 continue to explore the potential of oblimersen in combination with other therapies. Preclinical models have demonstrated that oblimersen, when combined with vinorelbine, significantly inhibits tumor growth and prolongs survival in NSCLC. These findings suggest that combining oblimersen with other chemotherapeutic agents could enhance its efficacy and potentially overcome previous clinical challenges.
Related Research Articles
Oligonucleotides are short DNA or RNA molecules, oligomers, that have a wide range of applications in genetic testing, research, and forensics. Commonly made in the laboratory by solid-phase chemical synthesis, these small fragments of nucleic acids can be manufactured as single-stranded molecules with any user-specified sequence, and so are vital for artificial gene synthesis, polymerase chain reaction (PCR), DNA sequencing, molecular cloning and as molecular probes. In nature, oligonucleotides are usually found as small RNA molecules that function in the regulation of gene expression, or are degradation intermediates derived from the breakdown of larger nucleic acid molecules.
Chronic lymphocytic leukemia (CLL) is a type of cancer in which the bone marrow makes too many lymphocytes. Early on, there are typically no symptoms. Later, non-painful lymph node swelling, feeling tired, fever, night sweats, or weight loss for no clear reason may occur. Enlargement of the spleen and low red blood cells (anemia) may also occur. It typically worsens gradually over years.
A locked nucleic acid (LNA), also known as bridged nucleic acid (BNA), and often referred to as inaccessible RNA, is a modified RNA nucleotide in which the ribose moiety is modified with an extra bridge connecting the 2' oxygen and 4' carbon. The bridge "locks" the ribose in the 3'-endo (North) conformation, which is often found in the A-form duplexes. This structure provides for increased stability against enzymatic degradation. LNA also offers improved specificity and affinity in base-pairing as a monomer or a constituent of an oligonucleotide. LNA nucleotides can be mixed with DNA or RNA residues in a oligonucleotide.
Bcl-2, encoded in humans by the BCL2 gene, is the founding member of the Bcl-2 family of regulator proteins. BCL2 blocks programmed cell death (apoptosis) while BCL2 family member can either inhibit or induce it. It was the first apoptosis regulator identified in any organism.
Antisense therapy is a form of treatment that uses antisense oligonucleotides (ASOs) to target messenger RNA (mRNA). ASOs are capable of altering mRNA expression through a variety of mechanisms, including ribonuclease H mediated decay of the pre-mRNA, direct steric blockage, and exon content modulation through splicing site binding on pre-mRNA. Several ASOs have been approved in the United States, the European Union, and elsewhere.
In molecular biology and genetics, the sense of a nucleic acid molecule, particularly of a strand of DNA or RNA, refers to the nature of the roles of the strand and its complement in specifying a sequence of amino acids. Depending on the context, sense may have slightly different meanings. For example, the negative-sense strand of DNA is equivalent to the template strand, whereas the positive-sense strand is the non-template strand whose nucleotide sequence is equivalent to the sequence of the mRNA transcript.
Bruton's tyrosine kinase, also known as tyrosine-protein kinase BTK, is a tyrosine kinase that is encoded by the BTK gene in humans. BTK plays a crucial role in B cell development.
Extranodal NK/T-cell lymphoma, nasal type (ENKTCL-NT) is a rare type of lymphoma that commonly involves midline areas of the nasal cavity, oral cavity, and/or pharynx At these sites, the disease often takes the form of massive, necrotic, and extremely disfiguring lesions. However, ENKTCL-NT can also involve the eye, larynx, lung, gastrointestinal tract, skin, and various other tissues. ENKTCL-NT mainly affects adults; it is relatively common in Asia and to lesser extents Mexico, Central America, and South America but is rare in Europe and North America. In Korea, ENKTCL-NT often involves the skin and is reported to be the most common form of cutaneous lymphoma after mycosis fungoides.
Phosphoinositide 3-kinase inhibitors are a class of medical drugs that are mainly used to treat advanced cancers. They function by inhibiting one or more of the phosphoinositide 3-kinase (PI3K) enzymes, which are part of the PI3K/AKT/mTOR pathway. This signal pathway regulates cellular functions such as growth and survival. It is strictly regulated in healthy cells, but is always active in many cancer cells, allowing the cancer cells to better survive and multiply. PI3K inhibitors block the PI3K/AKT/mTOR pathway and thus slow down cancer growth. They are examples of a targeted therapy. While PI3K inhibitors are an effective treatment, they can have very severe side effects and are therefore only used if other treatments have failed or are not suitable.
Genta Incorporated was a biopharmaceutical company started in La Jolla, California, which discovered and developed innovative drugs for the treatment of patients with cancer. Founded in 1989 by a highly skilled entrepreneur, the company focused on a novel technology known as antisense, which targets gene products that are associated with the onset and progression of serious diseases. At that time, only Ionis Pharmaceuticals, Inc. was conducting significant research with this technology. Antisense is a short span of oligonucleotides – modified DNA structures ranging from about 12-24 bases that selectively bind to specific RNA. The intent is to block expression of an aberrant protein that contributes to the disease of interest. Genta in-licensed three different antisense molecules that blocked Bcl-2, a fibroblast growth factor (FGF), and the gene c-myb, respectively.
Gene expression profiling has revealed that diffuse large B-cell lymphoma (DLBCL) is composed of at least 3 different sub-groups, each having distinct oncogenic mechanisms that respond to therapies in different ways. Germinal Center B-Cell like (GCB) DLBCLs appear to arise from normal germinal center B cells, while Activated B-cell like (ABC) DLBCLs are thought to arise from postgerminal center B cells that are arrested during plasmacytic differentiation. The differences in gene expression between GCB DLBCL and ABC DLBCL are as vast as the differences between distinct types of leukemia, but these conditions have historically been grouped together and treated as the same disease.
Ibrutinib, sold under the brand name Imbruvica among others, is a small molecule drug that inhibits B-cell proliferation and survival by irreversibly binding the protein Bruton's tyrosine kinase (BTK). Blocking BTK inhibits the B-cell receptor pathway, which is often aberrantly active in B cell cancers. Ibrutinib is therefore used to treat such cancers, including mantle cell lymphoma, chronic lymphocytic leukemia, and Waldenström's macroglobulinemia. Ibrutinib also binds to C-terminal Src Kinases. These are off-target receptors for the BTK inhibitor. Ibrutinib binds to these receptors and inhibits the kinase from promoting cell differentiation and growth. This leads to many different side effects like left atrial enlargement and atrial fibrillation during the treatment of Chronic Lymphocytic Leukemia.
Navitoclax is an experimental orally active anti-cancer drug, which is a Bcl-2 inhibitor similar in action to obatoclax.
Venetoclax, sold under the brand names Venclexta and Venclyxto, is a medication used to treat adults with chronic lymphocytic leukemia (CLL), small lymphocytic lymphoma (SLL), or acute myeloid leukemia (AML).
Umbralisib, sold under the brand name Ukoniq, is an anti-cancer medication for the treatment of marginal zone lymphoma (MZL) and follicular lymphoma (FL). It is taken by mouth.
Julianna Lisziewicz is a Hungarian immunologist. Lisziewicz headed many research teams that have discovered and produced immunotheraputic drugs to treat diseases like cancer and chronic infections like HIV/AIDS. Some of these drugs have been successfully used in clinical trials.
Custirsen, with aliases including custirsen sodium, OGX-011, and CC-8490, is an investigational drug that is under clinical testing for the treatment of cancer. It is an antisense oligonucleotide (ASO) targeting clusterin expression. In metastatic prostate cancer, custirsen showed no benefit in improving overall survival.
RNA therapeutics are a new class of medications based on ribonucleic acid (RNA). Research has been working on clinical use since the 1990s, with significant success in cancer therapy in the early 2010s. In 2020 and 2021, mRNA vaccines have been developed globally for use in combating the coronavirus disease. The Pfizer–BioNTech COVID-19 vaccine was the first mRNA vaccine approved by a medicines regulator, followed by the Moderna COVID-19 vaccine, and others.
Bisantrene is an anthracenyl bishydrazone with anthracycline-like antineoplastic activity and an antimetabolite. Bisantrene intercalates with and disrupts the configuration of DNA, resulting in DNA single-strand breaks, DNA-protein crosslinking, and inhibition of DNA replication. This agent is similar to doxorubicin in chemotherapeutic activity, but unlike anthracyclines like doxorubicin, it exhibits little cardiotoxicity.
Pirtobrutinib, sold under the brand name Jaypirca, is an anticancer medication that is used to treat mantle cell lymphoma. It inhibits B cell lymphocyte proliferation and survival by binding and inhibiting Bruton's tyrosine kinase (BTK). It is taken by mouth.
References
↑ Dias N, Stein CA (November 2002). "Potential roles of antisense oligonucleotides in cancer therapy. The example of Bcl-2 antisense oligonucleotides". European Journal of Pharmaceutics and Biopharmaceutics. 54 (3): 263–9. doi:10.1016/S0939-6411(02)00060-7. PMID12445555.
This page is based on this Wikipedia article Text is available under the CC BY-SA 4.0 license; additional terms may apply. Images, videos and audio are available under their respective licenses.
(what is this?) (verify) 
