Increased SPINK1 concentrations have been observed in serum from patients with gastric cancer and this has been associated with advanced stage (67).
Increased SPINK1 concentrations have been found in the serum of renal cell carcinoma (RCC) patients and this has been shown to correlate with stage (71).
SPINK1 expression has been detected by immunohistochemistry in the gallbladder (73) and in cholangiocarcinoma (21 ).
In a study comparing SPINK1 with several other markers, serum SPINK1 was found to be especially useful for diagnosis of esophageal cancer (16).
Serum SPINK1 concentrations, although higher in cancer patients than in controls (76), have not been found to be diagnostically useful in head and neck cancer (77).
Development of RIAs with rabbit antisera facilitated measurement of SPINK1 in serum and urine (4, 13).
SPINK1 in serum and urine can also be determined by LC-MS in combination with immunocapture with magnetic beads (83).
Potential Use of SPINK1 as a Therapeutic Target in Cancer
SPINK1 is expressed in variety of cancers and in the majority of them this indicates poor prognosis.
However, systemic inhibition of SPINK1 may be problematic, as it protects the pancreas against premature activation of trypsinogen, and interference of this mechanism is likely to increase the risk of pancreatitis.
A majority of the oncogenic functions of SPINK1 seem to be mediated by the MAPK pathway (27, 36, 59, 66).
SPINK1 has many important roles in various physiological and pathological processes.