Cellular level- cancer therapy Dr. P. Suganya Assistant Professor Departement of Biotechnology Sri Klaiswari College(Autonomous), Sivakasi
Cancer It is a group of diseases characterized by uncontrolled cell division leading to the growth of abnormal tissue / tumor Cell Proliferation Cell multiplication in normal Physiological process To replace cells that have been shed as a part of their life cycle ( eg ; skin, mucous membrane, GI tract, etc.)
Defect in Cellular Proliferation Cancer cells are characterized by the loss of contact inhibition Grow on top of one another and on top of or between normal cells Cancer cells respond differently than normal cells to intracellular signals regulating equilibrium Divide indiscriminately and haphazardly
Defect in Cellular Proliferation Once mutated, the cell can Die Recognize damage and repair itself Survive and pass on damage Surviving mutated cells have potential to become malignant
Normal cellular differentiation
Defect in Cellular Proliferation Pyramid effect Each cell division creates two or more offspring cells Continuous tumor growth Protooncogenes Normal cellular genes that are important regulators on normal cellular processes Mutations that alter their expression can activate them to act as oncogenes (tumor-inducing) Tumor suppressor genes Suppress growth of tumors Mutations render them inactive
Benign versus Malignant Tumors Characteristic Benign Malignant Differentiation Well differentiated Anaplastic Growth Rate Slow Rapid Mode of growth Expansive Infiltrative and expansive Metastases None Can spread to distant sites Prognosis Usually harmless Can be fatal if not treated
Development of Cancer Chemical, environmental, genetic, immunologic, viral, or spontaneous in origin Initiation Mutation of genetic structure Has potential to develop into clone of neoplastic cells
Progress of cancer treatment
Development of Cancer Promotion Characterized by the reversible proliferation of altered cells Activities of promotion (e.g. obesity, smoking, alcohol) are reversible Latent period Initial genetic alteration to clinical evidence of cancer
Development of Cancer Progression Characterized by increased growth rate of tumor as well as its invasiveness and metastasis Metastasis = spread of cancer from primary (initial) site to distant site
Role of Immune System Immune response is to reject or destroy cancer cells if perceived as non-self May be inadequate as cancer cells arise from normal human cells Some cancer cells have changes on their surface antigens Tumor-associated antigens (TAAs) Response to TAAs is termed immunologic surveillance Lymphocytes continually check cell surfaces and detect and destroy cells with abnormalities
Tumor Escape Mechanism Blocking antibodies prevent T cells from interacting with TAAs and from destroying the malignant cell
Development of tolerance of immune system Suppression of immune response to products secreted by cancer cells Induction of suppressor T cells Blocking antibodies that bind TAAs
Classification of Cancer Anatomic Site Classification Identified by tissue origin anatomic site behavior of the tumor (benign vs. malignant)
Anatomic Site Classification Carcinomas originate from embryonal ectoderm and endoderm Sarcomas originate from embryonic mesoderm Lymphomas and leukemias originate from hepatopoietic system
Classification of Cancer Histologic Analysis Classification Based on cellular appearance and differentation Grade 1: Differ slightly from normal; well differentiated Grade 2: More abnormal; moderately differentiated Grade 3: Vert abnormal; poorly differentiated Grade 4: Immature, primitive and undifferentiated cells; difficult to determine cell of origin
Classification of Cancer Clinical Staging 0: cancer in situ 1: tumor limited to tissue of origin 2: limited local spread 3: extensive local and regional spread 4: metastasis TNM Classification Tumor size Spread to lymph nodes Metastasis
Cancer Prevention and Detection Reduce or avoid exposure to known or suspected carcinogens Eat balanced diet Exercise regularly Adequate rest Health examination on a regular basis Eliminate, reduce, or change perceptions of stressors and enhance ability to cope Enjoy consistent periods of relaxation and leisure Know 7 warning signs of cancer Self-examination Seek medical care if cancer is suspected
Seven Warning Signs of Cancer C hange in bowel or bladder habits A sore throat that does not heal U nusual bleeding or discharge from body orifice T hickening or lump in breast or elsewhere I ndigestion of difficulty in swallowing O bvious change in wart or mole N agging cough or hoarseness
TYPES OF TUMOR TYPES OF TUMORB 1.Benign tumors 2 . Malignant tumors
Types of cancer Classified by type of cell, in which originates and by the location of the cells Cell Epithelial Blood cells Lymphatic Connective tissue Melanocyte Germ cells Site/location Digestive tract WBC Lymph note Bone Skin Testes/ovary Cancer Carcinoma Leukemia lymphoma Sarcoma Melanoma Terratoma
ETIOLOGY OF CANCER physical Chemical Biological Environmental factors Hormones Genetics Mutation
CYCLINS IN CELL CYCLE PROGRASSIVE CYCLIN D E, A B KINASE CDK4 CDK6 CDK2 CDK1 FUNCTION Prograssive past G1/s Boundary Initiation of DNA synthesis in early S phase Progression from G2 to M
Cancer treatment on a cellular level Radiation and Chemotheraphy Cyctoxin – absorb Nanoscale- lorry (Carrier)- transport the cytotoxin directly to the cancer cells via the blood stream and would prompt the cells to let the “load” in so that the cancer cells were destroyed
Doorways in to the cells A cell has a surrounding membrane that protects the cell against foreign substances But it also has KEYHOLES or RECEPTORS that can open up if the cell wants to let a substances enter. These substances must have a key that fits into the keyholes Sick Cells die, Healthy cells are unaffected The cancer cells actually absorbed packages wit the cytotoxin Cancer cells and healthy cells have very different metabolite and the two types of cells responded different to the encapsulated anti-cancer agents
NPs (Nanoparticles) with the cytotoxin were absorbed by the cancer cells Metabolism of the cancer cells to change and the cells showed signs that they were about to die. The healthy cells, meanwhile, do not show any evidences of absorbing the packages with the cytotoxin. This suggests that the method can be used to send cytotoxin around the body with reduced toxicity and could therefore be potentially safer for healthy cells.
Diagnosis of Cancer Biopsy involves histologic examination by a pathologist of a piece of tissue Needle Incisional Excisional
Collaborative Care of Cancer Goals Cure Control Palliation
Major Treatment Modalities Surgery Radiation Chemotherapy Biologic Therapy Bone marrow or stem cell transplant
Radiation therapy Emission and distribution of energy through space or material medium Energy produced breaks bonds in DNA, leading to death at time of reproduction Affects both cancer as well as normal cells Normal tissues are usually able to recover Surgical therapy to cure or control Slow cancers are most amenable Margin of normal tissue must surround tumor
Radiation therapy Teletherapy Given via external beam from a machine Most common Brachytherapy Radioactive material implanted in or close to the tumor Patient is radioactive Precautions: time, distance, shielding
Chemotheraphy Goal is to reduce number of cancer cells in the tumor site(s) Several factors determine response of cancer cells Cancer cells can escape death by staying in the G phase Main problem is presence of drug- resistant resting and noncycling cells Chemotherapy effects on cells Cell cycle non-specific Cell cycle phase-specific
Chemotherapy Regional Administration Delivery of drug directly into the tumor sites Higher concentrations can be delivered with reduced systemic toxicity