Question: How do autoantibodies affect ion channels in LES and SCLC?

Context:
["The autoantibodies implicated in the Lambert-Eaton myasthenic syndrome (LES), which are known to inhibit ICa and INa in bovine adrenal chromaffin cells, also significantly inhibited INa in SCLC cells.", "These results indicate that (i) action potentials in human SCLC cells result from the regenerative increase in voltage-gated Na+ channel conductance; (ii) fundamental characteristics of SCLC Na+ channels are the same as the classical sodium channels found in a variety of excitable cells; and (iii) in some LES patients, SCLC Na+ channels are an additional target of the pathological IgG present in the patients' sera.", "Clinical features were those of LES and occurred insidiously in this 68-year old man: proximal weakness predominant in the lower limbs, generalized areflexia, dryness of the mouth and partial right eye palsy. Investigations disclosed a small cell lung cancer.", "Voltage-gated Ca2+ channels may be important to the secretion of ectopic hormones and the etiology and pathogenesis of Lambert-Eaton syndrome, an autoimmune disorder of the motor nerve terminal in which autoantibodies directed against voltage-gated Ca2+ channels are produced.", "Lambert-Eaton syndrome is a myasthenia-like syndrome of paraneoplastic origin which is often associated with anaplastic small-cell lung cancer.", "Small-cell lung cancer (SCLC) is the most common cause of LES.", "We report an unusual case of LES associated with large-cell neuroendocrine carcinoma (LCNEC) of the lung.", "The Lambert-Eaton syndrome is caused by antibodies against voltage-gated calcium channels and often occurs in patients with small cell lung cancer.", "A 53 year-old heavy smoker presented with a Lambert-Eaton myasthenic syndrome (LEMS). Bronchoscopy was normal but radiological examinations revealed a lymph node in site 4R. The pathological diagnosis after mediastinoscopy was negative. Twenty-five months later, an opacity on chest X-ray led to a biopsy which revealed a squamous cell carcinoma.", "LEMS is generally associated with small cell lung cancer occurring in three percent of cases.", "However, the case that we report shows the unusual association of LEMS with non small-cell lung cancer and highlights the difficulties associated in the management of this condition.", "LEMS has a high degree of coincidence (approximately 60%) with small cell lung cancer; the remaining 40% of patients with LEMS have no detectable tumor.", "BACKGROUND: To enhance the acknowledgement of Lambert-Eaton syndrome in patients with small cell lung cancer.", "There were 10 cases of Lambert-Eaton syndrome in 332 pathologically diagnosed small cell lung cancer", "Treatment of small cell lung cancer may improve the symptoms of Lambert-Eaton syndrome", "Improving the recognition of Lambert-Eaton syndrome may be helpful to identify early small cell lung cancer and improve the prognosis,as the symptom of muscular weakness usually appears early before the diagnosis of small cell lung cancer.", "The Lambert Eaton syndrome is a paraneoplastic manifestation of small-cell lung cancer in 50% of the cases unlike generalized myasthenia which apparently is never associated with small-cell lung cancer.", "Paraneoplastic Lambert-Eaton myasthenia syndrome is presented in two cases with small cell lung cancer.", "Human small-cell lung cancer (SCLC) cells are believed to express the antigens responsible for the production of pathological antibodies in the Lambert-Eaton syndrome (LES), a Ca2+ channel disorder in which quantal transmitter release from the motor nerve terminal is impaired.", "Lambert-Eaton myasthenic syndrome (LEMS) is a paraneoplastic autoimmune disorder caused by an IgG-mediated reduction in number of presynaptic voltage-gated calcium channels (VGCC) at the neuromuscular junction. In at least 50% of cases, the stimulus for antibody production may be VGCC on small cell lung cancer (SCLC)", "Also, there was no obvious band pattern distinguishing patients with LES from those with LES and concurrent SCLC.", "The cancer associated with LEMS was small-cell lung carcinoma (SCLC) in 15 cases and epidermoid lung carcinoma in 3 cases.", "Etiology of this disease is uncertain but in view of its frequent association with small cell lung cancer, this specific type of neoplasm may be implicated in the initiation of autoimmune response.", "Recent studies indeed support the possibility that the antigenic stimulus in the neoplastic form of LES may arise from voltage-dependent Ca2+ channels found in the lung cancer cells.", "In the majority of LEMS patients, those having detectable tumor, the disease is thought to occur as a result of immune response
["The autoantibodies implicated in the Lambert-Eaton myasthenic syndrome (LES), which are known to inhibit ICa and INa in bovine adrenal chromaffin cells, also significantly inhibited INa in SCLC cells.", "These results indicate that (i) action potentials in human SCLC cells result from the regenerative increase in voltage-gated Na+ channel conductance; (ii) fundamental characteristics of SCLC Na+ channels are the same as the classical sodium channels found in a variety of excitable cells; and (iii) in some LES patients, SCLC Na+ channels are an additional target of the pathological IgG present in the patients' sera.", "Clinical features were those of LES and occurred insidiously in this 68-year old man: proximal weakness predominant in the lower limbs, generalized areflexia, dryness of the mouth and partial right eye palsy. Investigations disclosed a small cell lung cancer.", "Voltage-gated Ca2+ channels may be important to the secretion of ectopic hormones and the etiology and pathogenesis of Lambert-Eaton syndrome, an autoimmune disorder of the motor nerve terminal in which autoantibodies directed against voltage-gated Ca2+ channels are produced.", "Lambert-Eaton syndrome is a myasthenia-like syndrome of paraneoplastic origin which is often associated with anaplastic small-cell lung cancer.", "Small-cell lung cancer (SCLC) is the most common cause of LES.", "We report an unusual case of LES associated with large-cell neuroendocrine carcinoma (LCNEC) of the lung.", "The Lambert-Eaton syndrome is caused by antibodies against voltage-gated calcium channels and often occurs in patients with small cell lung cancer.", "A 53 year-old heavy smoker presented with a Lambert-Eaton myasthenic syndrome (LEMS). Bronchoscopy was normal but radiological examinations revealed a lymph node in site 4R. The pathological diagnosis after mediastinoscopy was negative. Twenty-five months later, an opacity on chest X-ray led to a biopsy which revealed a squamous cell carcinoma.", "LEMS is generally associated with small cell lung cancer occurring in three percent of cases.", "However, the case that we report shows the unusual association of LEMS with non small-cell lung cancer and highlights the difficulties associated in the management of this condition.", "LEMS has a high degree of coincidence (approximately 60%) with small cell lung cancer; the remaining 40% of patients with LEMS have no detectable tumor.", "BACKGROUND: To enhance the acknowledgement of Lambert-Eaton syndrome in patients with small cell lung cancer.", "There were 10 cases of Lambert-Eaton syndrome in 332 pathologically diagnosed small cell lung cancer", "Treatment of small cell lung cancer may improve the symptoms of Lambert-Eaton syndrome", "Improving the recognition of Lambert-Eaton syndrome may be helpful to identify early small cell lung cancer and improve the prognosis,as the symptom of muscular weakness usually appears early before the diagnosis of small cell lung cancer.", "The Lambert Eaton syndrome is a paraneoplastic manifestation of small-cell lung cancer in 50% of the cases unlike generalized myasthenia which apparently is never associated with small-cell lung cancer.", "Paraneoplastic Lambert-Eaton myasthenia syndrome is presented in two cases with small cell lung cancer.", "Human small-cell lung cancer (SCLC) cells are believed to express the antigens responsible for the production of pathological antibodies in the Lambert-Eaton syndrome (LES), a Ca2+ channel disorder in which quantal transmitter release from the motor nerve terminal is impaired.", "Lambert-Eaton myasthenic syndrome (LEMS) is a paraneoplastic autoimmune disorder caused by an IgG-mediated reduction in number of presynaptic voltage-gated calcium channels (VGCC) at the neuromuscular junction. In at least 50% of cases, the stimulus for antibody production may be VGCC on small cell lung cancer (SCLC)", "Also, there was no obvious band pattern distinguishing patients with LES from those with LES and concurrent SCLC.", "The cancer associated with LEMS was small-cell lung carcinoma (SCLC) in 15 cases and epidermoid lung carcinoma in 3 cases.", "Etiology of this disease is uncertain but in view of its frequent association with small cell lung cancer, this specific type of neoplasm may be implicated in the initiation of autoimmune response.", "Recent studies indeed support the possibility that the antigenic stimulus in the neoplastic form of LES may arise from voltage-dependent Ca2+ channels found in the lung cancer cells.", "In the majority of LEMS patients, those having detectable tumor, the disease is thought to occur as a result of immune response

Answer: The autoantibodies implicated in the Lambert-Eaton myasthenic syndrome (LES) inhibit ICa and INa in bovine adrenal chromaffin cells and significantly inhibit INa in SCLC cells.