Multidrug resistance in tumor cells is often attributed to extrusion of drugs mediated by overexpression of which of the following proteins?

Related MCQs

• A 29-year-old man was diagnosed with stage II (that is, spread from the primary tumor to retroperitoneal lymph nodes) nonseminomatous germ cell tumor 1 year ago. Treatment included orchiectomy and retroperitoneal lymph node dissection. He now presents with an elevated level of β-human chorionic gonadotropin hormone and multiple pulmonary lesions ranging in size from 0.61 to 3.22 cm. Needle biopsy specimen of the largest lesion reveals a germ cell tumor consistent with the initial diagnosis. He is asymptomatic. What is the best treatment for this patient?
• A 76-year-old male was admitted for symptoms including constipation, change in stool character and weight loss. Colonoscopy revealed multiple polyps in the rectosigmoid area. An adenomatous polyp was removed. Another colonic tumor was seen in the same patient which was flat with irregular “shaggy rug” surface. A biopsy showed frond-like glandular architecture. Atypical epithelial cells in clusters were seen beneath the muscularis mucosae. The most likely diagnosis is:
• A 40-year-old woman has a routine gynecologic examination. At the age of 32 years, she gave birth to twins after receiving fertility drugs. She has just seen a television program on ovarian cancer, and is concerned because previous use of fertility drugs and a family history of ovarian cancer were mentioned as possible risk factors. Her mother developed endometrial cancer at 56 years, and a paternal uncle was diagnosed with a type of lymphoma at 60 years. She has one older sister with hypertension and one younger brother who is healthy. Results of her pelvic examination are unremarkable, but she asks what additional tests she should have to look for ovarian cancer in the early stages that cannot be detected by physical examination. What is the most appropriate management for this patient?
• Mechanism of drug resistance of chemotherapeutic drugs
• A 40 year old female presents with mediastinal hilar lymphadenopathy and she has recently noticed slight weight loss and a cough. Staging shows no other evidence of disease. A trucut biopsy reveals a lymphoma showing large cells with mirror image nuclei, lymphocytes, plasma cells and eosinophils. The following phenotype is seen; CD20 positive, CD3 negative, CLA positive, and CD15 positive
• A 45-year-old woman is evaluated because of a palpable 2-cm right axillary lymph node. The lymph node is completely resected, and histologic study shows adenocarcinoma; hormone receptors are negative. Bilateral mammography is negative, as is MRI of the right breast. CT scans of the chest and abdomen are negative for tumor, and no further lymphadenopathy is detected. Results of bone scan and MRI of the head are also unremarkable. The patient had been previously healthy and has never smoked. Which of the following statements about this patients condition is correct?
• A 50-year-old menstruating woman has a 1 .5-cm moderately differentiated breast cancer. The lesion is completely excised, and the margins of the excision are negative. Axillary node sampling shows that she has three positive nodes. The tumor is negative for estrogen and progesterone receptors and is highly positive for HER2. She is otherwise healthy. Her mother had breast cancer at 62 years and was treated by mastectomy; she is alive and healthy at the age of 80 years. The patients sister had breast cancer at 54 years and was treated by breast conservation therapy; 4 years later she died of a recurrence of breast cancer. The patient has seen two different surgeons with opposing viewpoints regarding the best treatment, and she has been reading extensively on the Internet and has become confused about her options. Which of the following represents the best treatment for this patient?
• A 68-year-old man with a 60-pack-year smoking history is evaluated because of hemoptysis. Radiograph of the chest shows a right hilar mass and mediastinal widening. CT scans of the chest and abdomen confirm the hilar mass and bulky lymphadenopathy in the mediastinum with no other overt metastases. Bronchoscopic biopsy specimen shows small-cell lung cancer. Bone scan and CT scan of the head are negative for tumor. A low serum sodium level and inappropriately high urine osmolality suggest that he has the syndrome of inappropriate antidiuretic hormone secretion. Which of the following is the most appropriate treatment recommendation?
• A 52-year-old woman who is a nonsmoker has a 3-cm right inguinal lymph node.Biopsy specimen shows a poorly differentiated malignancy that is difficult to characterize by light microscopy. The biopsy specimen is negative for leukocyte common antigen, cytokeratin, and estrogen receptors. Which of the following additional tests would best establish the source of this tumor?
• Which of the following statement about tumor markers is correct?