Molecular Science

Basics     T lymphocytes activated in secondary lymphoid organs participate in anti-tumour immune response upon interaction with tumour-specific antigens.  However, tumour cells develop an immune suppressive tumour micro-environment to escape and downregulate the immune system. T-cells are associated with the different immune responses against tumours, CD8+ cells and CD4 + cells (T memory cells) are pro-inflammatory and glutarate anti-tumour responses in Fas ligand, perforin/granzyme pathways (CD8+ cells) or CD8+ cell activation via T memory cells. Whereas, a subset of CD4+ cells, Tregs induce an anti-tumor immune response by inhibiting dendritic cell activation or producing anti-inflammatory cytokines. Dendritic cells present tumour cells to T cells and work in close aid to counter tumour growth for the infiltration of T lymphocytes in the TME, while NK cells kill tumour cells lacking the MHC complex, which is invisible to CD8+ cells. Anti-tumour immune cells are primi...

Cancer Cancer is an uncontrolled, unrelenting proliferative cell disease that is linked to a number of additional complications. Cancer cells, malignant cells, or tumor cells are all names for this aberrant proliferative cell. Cancer cells do not reside at their original location; instead, they infiltrate and metastasize to other organs throughout the body, causing morbidity and mortality in people. Cancer is a major public health issue that ranks second in the world behind heart disease as the primary cause of death. Cancer metastasis is responsible for around 90% of all deaths among cancer patients. Cancer can affect almost any human tissue or organ, however, the likelihood of it happening differs depending on the tissue or organ.  The primary sites of cancer in humans are the tongue, mouth, pharynx, esophagus, stomach, small intestine, colon, rectum, anus, liver, intrahepatic bile duct, gallbladder, pancreas, larynx, lungs, bronchus, heart, skin, uterus, ovary, prostate, testi...

Mitochondria are important organelles in cellular metabolism. Several crucial metabolic pathways such as the energy-producing electron transport chain or the tricarboxylic acid cycle are hosted inside the mitochondria. The proper function of mitochondria depends on the import of proteins, which are encoded in the nucleus and synthesized in the cytosol. Micro-ribonucleic acids (miRNAs) are short non-coding ribonucleic acid (RNA) molecules with the ability to prevent messenger RNA (mRNA)-translation or to induce the degradation of mRNA-transcripts. Although miRNAs are mainly located in the cytosol or the nucleus, a subset of ~150 different miRNAs, called mitomiRs, has also been found localized to mitochondrial fractions of cells and tissues together with the subunits of the RNA-induced silencing complex (RISC); the protein complex through which miRNAs normally act to prevent translation of their mRNA-targets. A number of functions of mitomiRs are possible. Since cytosolic miRNAs inhibit...

  Intracellular generation of ROS/RNS and its signaling mechanism Increased levels of ROS and RNS are found in almost all types of cancers due to various reasons including rapid metabolic switch, increased growth rate, quick cell division, etc. However, tumor cells highly express antioxidants in response to increased oxidative stress. ROS and RNS possess single unpaired electrons in their outermost shell which makes them highly reactive. ROS and RNS include superoxide, hydroxyl radical, nitric oxide, peroxyl radical, nitroxyl anion, nitrosonium cation, higher oxides of nitrogen, etc. Non-radical ROS molecules are hydrogen peroxide and singlet oxygen etc.  Oxidative phosphorylation is the main source of ROS as complexes involving oxidative metabolism release them into the mitochondrial matrix or intermembrane space. The superoxides are generated by complex 1 and complex 3 and are released into intermembrane space or matrix (4). From intermembrane space, ROS are leaked into th...