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Turgor pressure within cells is regulated by osmosis and this also causes the cell wall to expand during growth. Along with size, rigidity of the cell is also caused by turgor pressure; a lower pressure results in a wilted cell or plant structure (i.e. leaf, stalk). One mechanism in plants that regulate turgor pressure is the cell's ...
Otto Warburg postulated this change in metabolism is the fundamental cause of cancer, [8] a claim now known as the Warburg hypothesis. Today, mutations in oncogenes and tumor suppressor genes are thought to be responsible for malignant transformation, and the Warburg effect is considered to be a result of these mutations rather than a cause. [9 ...
Some substances cause cancer primarily through their physical, rather than chemical, effects on cells. [32] A prominent example of this is prolonged exposure to asbestos, naturally occurring mineral fibers which are a major cause of mesothelioma, which is a cancer of the serous membrane, usually the serous membrane surrounding the lungs. [32]
There are multiple ways in which cancer cells can do this: by producing these signals themselves, known as autocrine signaling; by permanently activating the signaling pathways that respond to these signals; or by destroying 'off switches' that prevents excessive growth from these signals (negative feedback). In addition, cell division in ...
The central role of DNA damage and epigenetic defects in DNA repair genes in carcinogenesis. DNA damage is considered to be the primary cause of cancer. [17] More than 60,000 new naturally-occurring instances of DNA damage arise, on average, per human cell, per day, due to endogenous cellular processes (see article DNA damage (naturally occurring)).
A transmissible cancer is a cancer cell or cluster of cancer cells that can be transferred between individuals without the involvement of an infectious agent such as an oncovirus. [ 1 ] [ 2 ] The evolution of transmissible cancer has occurred naturally in other animal species, but human cancer transmission is rare. [ 2 ]
Furthermore, cancer cells with aberrant regulatory modifications in the chromatin of certain genes respond with different kinetics to cell stress, triggering expression of genes that protect them from cytotoxic conditions, and also by activating expression of genes that influence surrounding tissue in a manner that facilitates tumor growth. [14]
Tumor stroma and extracellular matrix in hypoxia. Tumor hypoxia is the situation where tumor cells have been deprived of oxygen.As a tumor grows, it rapidly outgrows its blood supply, leaving portions of the tumor with regions where the oxygen concentration is significantly lower than in healthy tissues.